Download Poster Session/ Cornea surgery, refractive

ARVO 2014 Annual Meeting Abstracts
222 Cornea surgery, refractive
Monday, May 05, 2014 8:30 AM–10:15 AM
Exhibit/Poster Hall SA Poster Session
Program #/Board # Range: 1512–1558/C0151–C0197
Organizing Section: Cornea
Program Number: 1512 Poster Board Number: C0151
Presentation Time: 8:30 AM–10:15 AM
A prospective study of corneal sensation following myopic LASIK
with two femtosecond lasers
Jennifer Kung, Edward E. Manche. Byers Eye Institute at Stanford,
Palo Alto, CA.
Purpose: Poor corneal sensation is a critical factor in the
development of post-LASIK dry eye. The purpose of this study is
to compare recovery of corneal sensation following standard versus
inverted side-cut LASIK flaps. Prior studies have suggested that
inverted side-cut LASIK flaps may have increased flap adhesion
post-operatively for better wound healing, more stability compared to
microkeratome flaps, and improved apposition of severed nerves.
Methods: 120 eyes of 60 patients underwent LASIK – one eye with a
150 kHz femtosecond laser using a 130 degree inverted side-cut and
the fellow eye with a 60 kHz femtosecond laser using a conventional
70 degree side-cut. All eyes underwent wavefront-guided ablation
with the AMO CustomVue S4 excimer laser. Cochet-Bonnet
aesthesiometry measured corneal sensation pre-operatively and at
post-operative months one, three, six and twelve.
Results: Cochet-Bonnet values were equal pre-operatively. Postoperative Cochet-Bonnet values were greater with inverted versus
conventional side-cuts with means of 14.5 > 13.2 (p = 0.08) at 1
month, 24.9 > 18.4 (p < 0.01) at 3 months, 51.2 > 42.6 (p < 0.01) at 6
months, and 59.8 > 58.3 (p < 0.01) at 12 months, respectively.
Conclusions: Eyes treated with an inverted side-cut had a faster
recovery of corneal sensation compared to eyes treated with a
conventional side-cut.
Commercial Relationships: Jennifer Kung, None; Edward E.
Manche, AMO (F), Best Doctors, Inc. (C), Calhoun Vision, Inc. (I),
Gerson Lehrmann (C), Krypton Vision, Inc. (I), Refresh Innovations,
Inc. (I), Seros Medical, LLC (I), Veralas, Inc. (I)
Support: Abbott Laboratories SPO#: 52712
Clinical Trial: NCT01365728
Program Number: 1513 Poster Board Number: C0152
Presentation Time: 8:30 AM–10:15 AM
Pachymetry and immunohistochemistry of LASIK flap created
by
different femtosecond lasers in eye-bank corneas
GRAZIELLY M. OLIVEIRA1, Adriana S. Forseto1, Maria Lúcia
Z. Dagli2, Vanessa V. Cordeiro1, Nicolas C. Pereira1, Walton
Nosé3. 1Department of Refractive Surgery, Sorocaba Eye Bank Sorocaba Ophthalmology Hospital, Sorocaba, Brazil; 2Department
of Pathology of the Faculty of Veterinary Medicine and Animal
Sciences, University of Sao Paulo, Sao Paulo, Brazil; 3Department of
Refractive Surgery, Eye Clinic, Sao Paulo, Brazil.
Purpose: The aim of this study was to compare the corneal
cell viability and thickness of the LASIK flap created by three
femtosecond lasers in eye-bank human corneas.
Methods: Forty five eye-bank human cornealscleral buttons (15
corneas in each group) were examined after the creation of 120
mm thickness laser assisted keratomileusis (LASIK) flaps with
the150kHz iFS IntraLase™ (IL), the Z6 Femto LDV™ (LDV) or the
200kHz Wavelight™ FS200 (FS200). The anterior segment optical
coherence tomography (ASOCT - Visante™) was used to measure
the thickness of the flaps vertically and horizontally at +0.5 mm;
+1.0 mm; +2.0 mm and +3.0 mm, and at -0.5 mm; -1.0 mm; -2.0
mm and -3.0 mm from the corneal vertex, and at +0.5 mm and -0.5
mm from the flap edge. Cellular viability was blinded evaluated with
immunohistochemistry for keratocyte apoptosis using anti-caspase 3
antibdy. Statistical analyzes were performed with Prism 5 software
(GraphPad Software Inc., San Diego, CA, USA) and was considered
a significance level set at p <0.05. Kruskal-Wallis test with Dunn’s
post-test was used to evaluate statistical difference in the thickness of
the flaps and keratocyte apoptosis.
Results: There was a statistically significant difference in the corneas
treated by LDV and IL between the flap thickness horizontally and
vertically at +0.5 mm, +1.0 mm, +2.0 mm, +3.00 mm, -0.5 mm, -1.00
mm, showed in table 1.
There was a statistically significant difference in the stromal
keratocyte apoptosis in corneas treated by LDV, FS200 and IL,
showed in table 1. Figure 1 shows corneal stromal keratocyte
apoptosis.
Conclusions: In this study, the flaps created with the IL were more
predictable than those with the LDV, but all the 3 groups showed a
low deviation from the intended flap thickness as described in the
literature. Keratocyte apoptosis was higher in corneas treated with
the LDV followed by those treated with the FS200 and with the
IL. Femtosecond laser technology has the advantage of producing
LASIK flap with good thickness predictability. Different keratocyte
apoptosis occurs with different femtosecond lasers equipments.
Table 1. Comparison of LASIK flap thickness and keratocyte
apoptosis between groups
Figure 1. Corneal stromal keratocytes apoptosis in the retroablation
zone of LASIK. Immunofluorescence in 40x.
Commercial Relationships: GRAZIELLY M. OLIVEIRA, None;
Adriana S. Forseto, None; Maria Lúcia Z. Dagli, None; Vanessa V.
Cordeiro, None; Nicolas C. Pereira, None; Walton Nosé, None
Support: NO SUPPORT
©2014, Copyright by the Association for Research in Vision and Ophthalmology, Inc., all rights reserved. Go to iovs.org to access the version of record. For permission
to reproduce any abstract, contact the ARVO Office at [email protected].
ARVO 2014 Annual Meeting Abstracts
Program Number: 1514 Poster Board Number: C0153
Presentation Time: 8:30 AM–10:15 AM
Correlated Changes of Wavefront and Corneal Topography
Aberrations Before and After Laser Refractive Treatment
Anatoly Fabrikant, Dimitri Chernyak. R&D, AMO Development
LLC, Fremont, CA.
Purpose: The Advanced WaveScan Studio makes multiple
measurements of the eye wavefront (WF) aberrations paired with
simultaneous and co-aligned corneal topography (CT) measurements.
Variations of measured WF may contribute to the errors in a laser
refractive treatment planning. Analysis of the treatment results
makes it necessary to compare WF and CT changes before and after
the surgery. The goal is to estimate precision of the eye WF and CT
measurements and to find out to what degree changes in corneal
anterior surface are responsible for the changes in WF aberrations
Methods: We perform a statistical analysis of pre-operative
measurement data and also paired pre-operative and 6M postoperative data from a retrospective clinical study (143 eyes).
We compare aberration deviations for multiple pre-operative
measurements of the same eye for synchronized WF and CT
measurements data. To make a fair comparison the WF center is
aligned with the corneal vertex, where the CT measurement is
centered. Also the light propagation change after the treatment is
taken into account.
Results: Variability of the WF and CT measurements in terms of
aberrations STD, high order RMS (HORMS) and total RMS (TRMS)
of multiple same eye measurements is shown in the Table 1.
Post-LASIK WF and CT aberration changes are well correlated (Fig.
1), which shows that WF aberration changes are almost entirely
defined by the corneal aberration changes.
Conclusions: Variations of WF aberrations up to TRMS=0.22um
make a substantial contribution to the refractive treatment errors.
Several pre-operative measurements followed with a careful selection
and/or averaging algorithm are necessary to alleviate these errors.
A fair comparison of CT and WF post-operative changes must take
into account WF center deviation from CT vertex position and postoperative optical path change.
A solid correlation between the CT and WF aberration changes,
caused by cornea ablation, shows that changes in the anterior corneal
surface have the greatest effect both on refraction and high-order
aberrations. Post-LASIK changes in the interior structure of the eye
do not affect post-operative aberrations.
Table 1. Variability of multiple measurements for the same eye
(n=367)
Fig.1. WF vs, CT post-LASIK aberration changes
Commercial Relationships: Anatoly Fabrikant, AMO
Development LLC (E); Dimitri Chernyak, AMO Development LLC
(E)
Program Number: 1515 Poster Board Number: C0154
Presentation Time: 8:30 AM–10:15 AM
Retinal nerve fiber layer thickness and ganglion cell complex
following LASIK with femtosecond laser flap creation
Andrew K. Lam1, Kenny K. Tam2, Peter S. Kwok2, Vincent W. Lee2,
3
, Zheng Wang2, Ricky T. Wu2, Elice Chan2, Ricky C. Chau2, Donica
C. Au2, Victor Woo2, 1. 1School of Optometry, The Hong Kong
Polytechnic University, Hong Kong, China; 2The Hong Kong Laser
Eye Centre, Hong Kong, China; 3Department of Ophthalmology,
University of Hong Kong, Hong Kong, China.
Purpose: To study the influence of laser in situ keratomileusis
(LASIK) with femtosecond laser flap creation on the retinal nerve
fiber layer (RNFL) thickness and ganglion cell complex (GCC).
Methods: One hundred eyes from one hundred myopic patients
received uneventful bilateral LASIK were recruited. Corneal flap at
superior hinge was created with femtosecond laser. For each patient,
either the eye with a greater amount of myopia reduction, or the
right eye if both eyes had the same amount of myopia reduction was
included. RNFL and GCC were measured using a spectral-domain
optical coherence tomography at baseline, and one-day and onemonth after the LASIK procedures.
Results: There was no significant difference between the two eyes
at baseline in terms of the amount of myopia (spherical equivalent)
and the central corneal thickness (CCT). On day one, the average (+/standard deviation) myopia reduction was found to be 6.62+/-2.29D
and with CCT thinning of 129.9+/-45.5um. There was no significant
difference in the Average RNFL as well as RNFL at the four
quadrants (Repeated Measures Analysis of Variance, RMANOVA, p
> 0.05). The Average GCC and GCC at both the superior and inferior
regions did not reach any significant difference (RMANOVA, p >
0.05).
Conclusions: Myopia LASIK with femtosecond laser flap does not
affect RNFL and GCC measurements.
Commercial Relationships: Andrew K. Lam, None; Kenny K.
Tam, None; Peter S. Kwok, None; Vincent W. Lee, None; Zheng
Wang, None; Ricky T. Wu, None; Elice Chan, None; Ricky C.
Chau, None; Donica C. Au, None; Victor Woo, None
Program Number: 1516 Poster Board Number: C0155
Presentation Time: 8:30 AM–10:15 AM
Large series comparison between a new high-resolution and
contemporary aberrometer in Wavefront-Guided LASIK to treat
low to moderate myopia
Steven C. Schallhorn1, Julie M. Schallhorn1, Craig S. Schallhorn2.
1
Department of Ophthalmology, University of California San
Francisco, San Francisco, CA; 2University of California San Diego,
San Diego, CA.
Purpose: To provide a retrospective comparison of one month
outcomes of wavefront-guided (WFG) LASIK using a new (iDesign,
Abbott Medical Optics) and contemporary (WaveScan, Abbott
Medical Optics) aberrometer for the treatment of low to moderate
myopia.
Methods: Consecutive WFG LASIK conducted in a multi-center
practice in the UK (Optical Express) performed with either the new
or contemporary aberrometer to treat low to moderate myopia (up to
-6D sphere) and cylinder (up to 6D) were retrospectively analyzed.
Flap creation methods and other surgical parameters were the same
in both groups. Uncorrected visual acuity (UCVA) and predictability
©2014, Copyright by the Association for Research in Vision and Ophthalmology, Inc., all rights reserved. Go to iovs.org to access the version of record. For permission
to reproduce any abstract, contact the ARVO Office at [email protected].
ARVO 2014 Annual Meeting Abstracts
of refraction as well as patient-reported outcomes were evaluated at 1
month postoperative.
Results: There were 8,905 consecutive eyes of 4,721 patients
treated using the new aberrometer and 27,290 eyes of 14,589
patients treated with the contemporary aberrometer included in the
study. Demographic and preop characteristics were well-matched
between the two groups. At 1 month postop, more eyes achieved
20/16 and 20/20 uncorrected distant vision with the new aberrometer
compared to the contemporary (new aberrometer: 84.0% and 95.4%;
contemporary: 79.7% and 93.8% of eyes with 20/16 and 20/20
UCVA, respectively). The refractive predictability was excellent, with
95.4% and 93.9% of eyes were within 0.5 D of intended MSE in the
new and contemporary groups, respectively. The cylinder correction
ratio was >0.9 for all levels of astigmatism correction but the new
aberrometer had less variance in outcomes and a significantly higher
percentage of patients with <=0.5D of cylinder postoperative (95.8%)
compared to the contemporary cohort (92.6%). The loss of > 2 lines
of best corrected visual acuity was very low in both groups (0.1%
and 0.2% in the new and contemporary groups). More patients were
satisfied with the outcome of the procedure outcome with the new
aberrometer (96.5% vs 95.2%, respectively, p=0.01, chi-squared).
Conclusions: In this retrospective evaluation of early postoperative
outcomes, the new aberrometer WFG LASIK had improved efficacy
(UCVA, refractive predictability, and cylinder correction) and higher
patient satisfaction compared to contemporary WFG LASIK.
Commercial Relationships: Steven C. Schallhorn, Abbott Medical
Optics (C); Julie M. Schallhorn, None; Craig S. Schallhorn, None
Program Number: 1517 Poster Board Number: C0156
Presentation Time: 8:30 AM–10:15 AM
LASIK for high hyperopic astigmatism
Timothy Archer1, Dan Z. Reinstein1, 2, Marine Gobbe1. 1London
Vision Clinic, London, United Kingdom; 2Ophthalmology, Columbia
University Medical Center, New York, NY.
Purpose: Report the visual outcomes of high hyperopic LASIK using
the MEL80 excimer laser.
Methods: Retrospective analysis of 798 consecutive high hyperopic
LASIK procedures (651 patients) using the MEL80 excimer laser
and either the Hansatome microkeratome or VisuMax femtosecond
laser. Inclusion criteria were attempted maximum hyperopic meridian
≥+4.00D, CDVA 20/20 or better, and minimum follow-up of 1 year.
Standard outcomes analysis, including contrast sensitivity, was
performed for the primary procedure and including retreatments.
The primary procedure was a partial correction in 160 eyes (20%),
of which 81 (51%) have undergone a retreatment to date. Of the
637 eyes intended for full correction, 220 (35%) have undergone a
retreatment. Prior to retreatment, epithelial thickness and residual
stromal thickness were measured by Artemis VHF digital ultrasound.
A retreatment was performed if the predicted residual stromal
thickness was >250 mm at the location of the maximum ablation and
the minimum epithelial thickness was >30 mm.
Results: Mean attempted SEQ was +4.00±0.90D (+2.00 to +7.64D)
for the primary procedure, and +4.69±1.03D (+2.00 to +9.50D)
including all procedures. Mean attempted maximum hyperopic
meridian including all procedures was +5.21±1.03D (+4.00 to
+9.75D).Preoperatively, mean refractive astigmatism was 1.04±0.86D
(0.00 to 5.25D), mean age was 51±12 years (18 to 70 years), mean
average keratometry was 43.3±1.5D (38.7 to 48.3D). After all
treatments, SEQ relative to the intended target was +0.10±0.69D
(-2.38 to +3.46D) and was ±0.50D in 67% and ±1.00D in 89% of
eyes. Over time, mean SEQ was 0.00D at 3 months (n=753), +0.11D
at 6 months (n=600), +0.24D at 1 year (n=736) and +0.43D at 2 years
(n=452). Postoperatively, refractive astigmatism was 0.77±0.58 D
(0.00 to 3.50 D). UDVA was 20/20 or better in 76% and 20/40 or
better in 98% of eyes. There was a loss of 1 line of CDVA in 26%, 2
lines in 0.5% of eyes, and no eyes lost >2 lines. Contrast sensitivity
was decreased (p<0.05) by <1 patch at 3 and 6 cpd, and by 1 patch
at 12 and 18 cpd. Postoperatively, mean average keratometry was
46.7±1.9D (41.0 to 52.7D). Two patients (3 eyes) experienced diurnal
fluctuation in refraction proven by VHF digital ultrasound to be due
to diurnal epithelial remodelling overnight and unrelated to maximum
postop SimK induced (range 46.0-51.3D).
Conclusions: LASIK for hyperopia up to +9.50 D with the MEL80
excimer laser was found to be safe, effective and stable.
Commercial Relationships: Timothy Archer, None; Dan Z.
Reinstein, ArcScan Inc (I), Carl Zeiss Meditec (C); Marine Gobbe,
None
Program Number: 1518 Poster Board Number: C0157
Presentation Time: 8:30 AM–10:15 AM
Vector analysis of compound myopic astigmatism comparing
wavefront-guided and wavefront-optimized excimer platforms
Brian C. Toy, Edward E. Manche. Byers Eye Institute, Stanford
University School of Medicine, Palo Alto, CA.
Purpose: To compare the astigmatic outcomes of laser in situ
keratomileusis (LASIK) with a single excimer laser platform using
either wavefront-guided (WFG) and a wavefront-optimized (WFO)
modes.
Methods: Seventy-two eyes of 36 patients underwent LASIK for
compound myopic astigmatism with the Alcon Wavelight Allegretto
Eye-Q 400 laser platform. One eye underwent WFG-LASIK, and
the contralateral eye underwent WFO-LASIK. Preoperative and
postoperative assessments were performed and included manifest
refraction, vector analysis, topographic analysis, and wavefront
aberrometry analysis. Eyes were stratified for subgroup analysis
based on preoperative manifest astigmatism: 0.25-1, 1.25-2.25, and
2.5-3.5 diopters. Statistics were calculated using t-tests.
Results: Preoperatively, mean spherical equivalent (SE) was -4.0±1.7
vs -3.9±1. diopters(D) (p=0.67), and mean cylindrical error(CE) was
0.7±0.5 vs 0.8±0.8D (p=0.47) in the Alcon-WFG and Alcon-WFO
groups, respectively. At postoperative month 12, mean SE was -0.2
±0.3 vs -0.3±0.3D (p=0.03), and mean CE was 0.2±0.2 vs 0.1±0.2D
(p=0.46), respectively.
Alpins vector analyses for the Alcon-WFG and Alcon-WFO groups,
respectively, were: surgically-induced-astigmatism (0.8±0.6 vs
0.8±0.8D, p=0.94), error-magnitude (0.1±0.2 vs 0.1±0.2D, p=0.77),
error-angle (10±37° vs 19±44°, p=0.4), correction-index (1.1±0.3
vs 1±0.3, p=0.1), success-index (0.2±0.3 vs 0.2±0.4, p=0.45), and
flattening-index (0.8±0.5 vs 0.9±0.8, p=0.19).
Subgroup analysis by preoperative astigmatism showed no significant
differences.
Conclusions: Minimal difference in outcomes between Alcon-WFG
and Alcon-WFO platforms based on objective Alpins analysis of
astigmatism.
Commercial Relationships: Brian C. Toy, None; Edward E.
Manche, None
Clinical Trial: NCT01138189
Program Number: 1519 Poster Board Number: C0158
Presentation Time: 8:30 AM–10:15 AM
Monocular LASIK in adult patients with anisometropic
amblyopia
Alejandro Tamez, Julio C. Hernandez, Juan F. Lozano, Guillermo
Mendoza, Jesus Lozano, Jorge E. Valdez. Ophthalmology, Tec Salud,
San Pedro Garza Garcia, Mexico.
©2014, Copyright by the Association for Research in Vision and Ophthalmology, Inc., all rights reserved. Go to iovs.org to access the version of record. For permission
to reproduce any abstract, contact the ARVO Office at [email protected].
ARVO 2014 Annual Meeting Abstracts
Purpose: To investigate the efficacy and safety of LASIK for the
correction of anisometropic amblyopia in adult patients.
Methods: A retrospective, case series. From a random sample of
1500 patients from the Cornea and Refractive service, we found
12 amblyopic adult patients that underwent monocular LASIK for
anisometropia. We evaluated the preoperative and postoperative
refractive error, spherical equivalent (SE), uncorrected visual acuity
(UCVA) and best corrected visual acuity (BCVA). Snellen visual
acuity measurements were converted to LogMAR for statistical
purposes.
Results: The mean age was 31.92 (±12.13) years. The average
preoperative SE in the treated eyes was -3.49 (±3.24), the average
SE of the untreated eye was 0.25(±0.30). Preoperative UCVA was
1.12 (±0.3) and average preoperative BCVA was 0.31 (±0.1). All
patients had LASIK with an average follow-up time of 19.1(1-74)
months. The average postoperative SE decreased to -0.28 (±0.48).
Five patients (42%) gained 1 line of vision, 1 (8%) patient gained
2 lines of vision, 1 (8%) patient gained 3 lines of vision and the
rest (42%) remained unchanged compared to preoperative BCVA.
Statistically significant differences were observed between the
preoperative UCVA [1.12 (±0.3)] with the postoperative UCVA [0.27
(±0.1)](p<0.001, paired T-Test) and between the postoperative BCVA
[0.23 (±0.12)] with the preoperative BCVA [0.31 (±0.1)] (p=0.02,,
paired T-Test). There were no complications related to the surgical
procedures.
Conclusions: Monocular refractive surgery in adult patients
with anisometropic amblyopia is a safe and effective therapeutic
option that offers a satisfactory visual outcome, preserving or even
improving the preoperative BCVA.
Commercial Relationships: Alejandro Tamez, None; Julio C.
Hernandez, None; Juan F. Lozano, None; Guillermo Mendoza,
None; Jesus Lozano, None; Jorge E. Valdez, None
Program Number: 1520 Poster Board Number: C0159
Presentation Time: 8:30 AM–10:15 AM
Rate of Ingrowth After Flap-lift LASIK Retreatment
Jessica M. Kang1, Anupam Jayaram2, Pamela Stewart2, Michael A.
Rosenberg2. 1Feinberg School of Medicine, Northwestern University,
Chicago, IL; 2Ophthalmology, Northwestern University, Chicago, IL.
Purpose: The objective of this study is to assess the rate of epithelial
ingrowth after flap-lift LASIK retreatment and secondarily to
evaluate risk factors for ingrowth such as time from primary LASIK,
pre-primary and pre-retreatment refractive error, and method of
original flap creation. This is the largest study to date to examine this,
and includes over 750 eyes. Previous studies report ingrowth with
varying frequency, but more often if retreatment was done over 3
years after primary LASIK, in hyperopic eyes, and with flap creation
by microkeratome as compared to femtosecond laser. Reported rates
of post-retreatment ingrowth in much smaller studies have been as
high as 41%, and up to 6% for ingrowth requiring surgical removal.
Methods: An IRB approved retrospective chart review was
performed of all cases of flap-lift LASIK retreatment done by a
single surgeon (MR) at Northwestern Memorial Faculty Foundation
from July 1999 to May 2013. Eyes without recorded post-procedure
follow up by 1 month were excluded from the study. Time from
primary treatment, method of flap creation, best uncorrected and
pre-retreatment refractive error, patient age at time of procedure,
and incidence of clinically significant ingrowth were recorded.
Ingrowth was classified as either requiring observation or surgical
management. Eyes that were retreated multiple times were included
but analyzed in a separate category.
Results: The average patient age at time of procedure was 38 years.
The average spherical equivalent prior to primary LASIK was
-5.03, and prior to retreat was -0.71. The rate of epithelial ingrowth
after retreatment was as low as 1%. Of note, this rate did not differ
significantly from rate of ingrowth after primary LASIK in eyes
requiring retreatment (2%). Time to retreatment, age at time of
procedure, pre-primary and pre-retreatment refractive error, and
method of original flap creation did not significantly impact risk of
ingrowth.
Conclusions: In this large retrospective study of over 750 eyes
which underwent LASIK retreatment, the rate of epithelial ingrowth
after flap-lifting procedure was low for all patients regardless of
timing and method of original LASIK. When considering methods
for LASIK retreatment, flap lifting may offer a preferable option
compared to PRK in terms of patient comfort and recovery time.
Physicians should not be deterred from flap lifting as an alternative to
PRK out of concern for development of ingrowth.
Commercial Relationships: Jessica M. Kang, None; Anupam
Jayaram, None; Pamela Stewart, None; Michael A. Rosenberg,
None
Program Number: 1521 Poster Board Number: C0160
Presentation Time: 8:30 AM–10:15 AM
INTRAOPERATIVE FLAP COMPLICATIONS IN LASIK
SURGERY PERFORMED BY OPHTHALMOLOGY
RESIDENTS IN TRAINING
Lorena Romero-Díaz-de-León, Juan Carlos Serna- Ojeda, Arturo
J. Ramirez-Miranda, Enrique O. Graue. Instituto de Oftalmología
Conde de Valenciana IAP, Mexico City, Mexico.
Purpose: To determine the incidence of flap-related complications
in LASIK surgery performed by in-training ophthalmology residents
and the risk factors involved in those complications.
Methods: We analyzed 219 flap sections from 118 patients from
March to December 2013. We included all cases performed by 25
ophthalmology residents using a Moria II microkeratome. All patients
were aware that a surgeon-in-training would be operating as part of
the surgical team.
Results: There were 16 flap-related complications out of the 219
flap sections involved (7.3%). The most common complication was
an incomplete flap section (n=8; 3.65%), followed by free-cap (n=4;
1.89%) and flap-buttonhole (n=2;0.94%). There were 2 infrequent
complications of an irregular flap and an oval flap that allowed
ablation.
Ablation treatment was not applied to 11 eyes out of the 16 flaprelated complications (68.75%). Flap-related complications were the
cause of 4 contralateral eye surgical suspensions. The relative risk for
ablation suspension is 1.4 (CI 95% 0.53 to 3.67) when an incomplete
flap section is presented.
There were no significant differences in right or left eye, flat or steep
keratometries, white-to-white diameter, plate size used or spherical
equivalent between complicated and uncomplicated cases. Final
visual acuity after rescheduling laser treatment was also similar
between complicated and uncomplicated groups.
Relative risks for flap-related complications were 1.5 for first flap
section (CI 95% 0.37 to 6.28) ; and 1.89 (CI 95% 0.71 to 5.04) for the
surgeon’s first twenty flap sections.
Conclusions: Flap-related complications are a common
intraoperative complication during LASIK surgery performed by intraining ophthalmologists.
Surgeon’s first twenty corneal sections represent a higher risk for flap
related complications than biometric parameters of patient’s eye.
Our incidence of flap related complications is just above the
incidence reported in literature. This type of complication is a major
cause of surgical suspension and the incidence should be considered
as part of the informed consent in training hospitals, although it does
©2014, Copyright by the Association for Research in Vision and Ophthalmology, Inc., all rights reserved. Go to iovs.org to access the version of record. For permission
to reproduce any abstract, contact the ARVO Office at [email protected].
ARVO 2014 Annual Meeting Abstracts
not seem to affect final visual outcome when the laser treatment is
rescheduled.
Commercial Relationships: Lorena Romero-Díaz-de-León, None;
Juan Carlos Serna- Ojeda, None; Arturo J. Ramirez-Miranda,
None; Enrique O. Graue, None
Program Number: 1522 Poster Board Number: C0161
Presentation Time: 8:30 AM–10:15 AM
Visual outcomes and the identification of static and dynamic
targets of military interest after Wavefront-guided (WFG) and
Wavefront-optimized (WFO) Photorefractive Keratectomy
(PRK)
Denise S. Ryan1, Rose K. Sia1, Dawne M. Deaver2, Tana Maurer2,
Christopher L. Howell2, Lorie A. Logan1, Jennifer B. Eaddy1, Joseph
F. Pasternak3, Richard Stutzman3, Kraig S. Bower4. 1Warfighter
Refractive Surgery and Research Center, Fort Belvoir, VA; 2Night
Vision and Electronic Sensors Directorate, Fort Belvoir, VA;
3
Ophthalmology, Walter Reed National Military Medical Center,
Bethesda, MD; 4The Wilmer Eye Institute, Johns Hopkins University,
Baltimore, MD.
Purpose: To evaluate the visual outcomes and the ability to identify
static and dynamic targets of military interest after WFG and WFO
PRK.
Methods: In this prospective randomized study, 27 myopic military
personnel underwent either WFG (n=14) or WFO PRK (n=13).
Subjective manifest refraction, uncorrected and corrected distance
visual acuities (UDVA and CDVA) were measured preoperatively
and at 1, 3, and 6 months postoperatively. Performance on military
tasks was determined before and after refractive surgery. Participants
were evaluated for their ability to discriminate vehicles and handheld
objects of military interest. Change in probability of identification
(PID) of the two target sets at different ranges was assessed at preop
and 6M postop for each participant. The Fisher exact test was used
to compare visual outcomes and military task performance between
the treatment groups. A p-value of <0.05 was considered statistically
significant.
Results: At 6 months postop, 100% WFG PRK versus 95.8% WFO
PRK treated eyes achieved UDVA ≥20/20. There were 96.4% WFG
PRK compared to 92.3% WFO PRK eyes maintaining manifest
spherical equivalent ±0.5 diopters of emmetropia. None lost more
than 2 lines of CDVA. For handheld object ID, at 6M, 9 of 10 WFG
PRK and 9 of 10 WFO PRK subjects performed equivalent to or
better than preop performance (p=0.99). There was 1 subject in each
group who performed more than one standard deviation (1σ) below
preop PID. For military vehicle ID, at 6M, 10 of 11 WFG PRK
subjects performed equivalent to or better than preop performance
while 9 of 10 WFO PRK subjects performed equivalent to or better at
6M (p=0.99). There was 1 subject in each group who performed more
than one standard deviation (1σ) below preop PID.
Conclusions: Comparing WFG and WFO PRK 6M postoperatively,
visual outcomes were favorable in both groups. Changes in military
task performance for ID of vehicles and handheld objects were
statistically equivalent between the treatment groups.
Commercial Relationships: Denise S. Ryan, None; Rose K. Sia,
None; Dawne M. Deaver, None; Tana Maurer, None; Christopher
L. Howell, None; Lorie A. Logan, None; Jennifer B. Eaddy, None;
Joseph F. Pasternak, None; Richard Stutzman, None; Kraig S.
Bower, None
Support: Dept of Defense W81XWH-09-2-0018
Clinical Trial: NCT01097525
Program Number: 1523 Poster Board Number: C0162
Presentation Time: 8:30 AM–10:15 AM
The Effect of Wavefront-guided (WFG) and Wavefront-optimized
(WFO) Photorefractive Keratectomy (PRK) on Subjective
Quality of Vision (QOV) and Military Task Performance (MTP)
among Active Duty U.S. Soldiers
Richard Stutzman1, Rose K. Sia2, Denise S. Ryan2, Tana Maurer3,
Christopher L. Howell3, Jennifer B. Eaddy2, Bruce A. Rivers2, Lamarr
Peppers2, Joseph F. Pasternak1, Kraig S. Bower4. 1Ophthalmology,
Walter Reed National Military Medical Center, Bethesda, MD;
2
Warfighter Refractive Surgery and Research Center, Fort Belvoir,
VA; 3Night Vision and Electronic Sensors Directorate, Fort Belvoir,
VA; 4The Wilmer Eye Institute, Johns Hopkins University, Baltimore,
MD.
Purpose: To determine the effect of WFG and WFO PRK on
soldiers’ self-reported QOV and the ability to detect and discriminate
human and combat vehicle targets presented in infrared imagery.
Methods: In this prospective study, 27 myopic military personnel
were randomized to undergo either WFG (n=14) or WFO PRK
(n=13). Participants were asked to complete a questionnaire that
focused on general satisfaction and QOV pre- and post-refractive
surgery. MTP was evaluated preoperatively as well as 6 weeks
and 6 months (M) postoperatively. In separate computer-based
tasks, participants were asked to 1) search for human targets in a
high clutter infrared scene; and 2) identify combat vehicle targets
using thermal signatures. Change in probability of detection (Pd)
and probability of identification (PID) at preop and 6M postop
was assessed. Repeat measures analysis of variance and the Fisher
exact test were performed to compare subjective QOV and MTP,
respectively, between the two treatment groups. A p-value of <0.05
was considered significant.
Results: There were no significant differences between WFG and
WFO PRK for self-reported glare (p=0.94), halo (p=0.95) or visual
difficulties in performing daily activities (p=0.27) over the 6M postop
period. On a 10-point scale, one being the highest, overall expectation
for vision was comparable at 6M postop (mean: 2.1 WFG, 1.7 WFO;
p=0.36). There was no significant difference in patient satisfaction
when participants were asked about the chance to have the procedure
again (score: 1.1 WFG, 1.1 WFO; p=0.91). WFG and WFO PRK
were comparable in MTP (p=0.99) at 6M postop. For human search,
8 of 10 WFG subjects scored equivalent to or better than preop Pd,
while 2 subjects decreased Pd by more than 1 standard deviation (σ).
Six of 7 WFO subjects scored equivalent to or better than preop Pd,
while 1 subject decreased Pd by more than 1σ. For combat vehicle
ID, 10 of 11 WFG subjects scored equivalent to or better than preop
PID. Seven of 8 WFO subjects scored equivalent to or better than
preop PID. One subject in each group decreased PID by more than
1σ.
Conclusions: Soldiers who underwent either WFG or WFO PRK
were highly satisfied with their vision overall. Changes in MTP for
human detection and vehicle ID were statistically equivalent between
WFG and WFO PRK.
Commercial Relationships: Richard Stutzman, None; Rose
K. Sia, None; Denise S. Ryan, None; Tana Maurer, None;
Christopher L. Howell, None; Jennifer B. Eaddy, None; Bruce A.
Rivers, None; Lamarr Peppers, None; Joseph F. Pasternak, None;
Kraig S. Bower, None
Support: Department of Defense W81XWH-09-2-0018
Clinical Trial: NCT 01097525
©2014, Copyright by the Association for Research in Vision and Ophthalmology, Inc., all rights reserved. Go to iovs.org to access the version of record. For permission
to reproduce any abstract, contact the ARVO Office at [email protected].
ARVO 2014 Annual Meeting Abstracts
Program Number: 1524 Poster Board Number: C0163
Presentation Time: 8:30 AM–10:15 AM
Contrast Sensitivity after Wavefront-optimized (WFO) and
Wavefront-guided (WFG) Photorefractive Keratectomy (PRK)
and its Effect on Military Target Identification
Rose K. Sia1, Denise S. Ryan1, Steven Moyer2, Tana Maurer2, Lorie A.
Logan1, Bruce A. Rivers1, Joseph F. Pasternak3, Richard Stutzman3,
Lamarr Peppers1, Kraig S. Bower4. 1Warfighter Refractive Surgery
and Research Center, Fort Belvor, VA; 2Night Vision and Electronic
Sensors Directorate, Fort Belvoir, VA; 3Ophthalmology, Walter Reed
National Military Medical Center, Bethesda, MD; 4The Wilmer Eye
Institute, Johns Hopkins University, Baltimore, MD.
Purpose: To determine the effect of contrast sensitivity after WFO
and WFG PRK in the ability to identify armored vehicles of military
interest.
Methods: This is a prospective study of 27 myopic participants
randomized to undergo either WFO (n=13) or WFG PRK
(n=14). Corrected distance high and low contrast visual acuities
were determined preoperatively and at 1, 3, and 6 months
(M) postoperatively. Military task performance was evaluated
preoperatively (corrected visual acuity) as well as 6 weeks and
6M postoperatively (uncorrected visual acuity). Participants
were asked to identify combat vehicles in varying contrasts using
software. Change in probability of identification (PID) for each
observer preoperatively and 6M postoperatively was assessed.
Repeated measures analysis of variance and the Fisher exact test
were performed to compare contrast sensitivity and military task,
respectively, between the treatment groups. A p-value of <0.05 was
considered statistically significant.
Results: WFO PRK seemed to outperform WFG PRK in SuperVision
high contrast, SuperVision low contrast, Night Vision, and 25%
low contrast acuity tests (p≤0.01) but not in 5% low contrast acuity
(p=0.14). There was no significant difference between the treatment
groups in their ability to identify military vehicles (p=0.59) at 6M
postoperatively. Eight of 10 WFO PRK participants performed
equivalent to or better than preoperative PID, while two participants
performed more than one standard deviation (1σ) below preoperative
PID. Ten of 11 WFG PRK participants performed equivalent to or
better than preoperative PID, while one participant performed more
than 1σ below preoperative PID.
Conclusions: Performance in high and low contrast acuity tests
appeared to be better after WFO PRK than after WFG PRK.
However, performance of participants in the WFO and WFG PRK
groups were statistically comparable in their ability to identify
vehicles of military interest presented in varying contrasts.
Commercial Relationships: Rose K. Sia, None; Denise S. Ryan,
None; Steven Moyer, None; Tana Maurer, None; Lorie A. Logan,
None; Bruce A. Rivers, None; Joseph F. Pasternak, None; Richard
Stutzman, None; Lamarr Peppers, None; Kraig S. Bower, None
Support: Dept of Defense W81XWH-09-2-0018
Clinical Trial: NCT01097525
Program Number: 1525 Poster Board Number: C0164
Presentation Time: 8:30 AM–10:15 AM
Visual Performance after Wavefront-guided and Wavefrontoptimized Photorefractive Keratectomy (PRK) and Laser in situ
keratomileusis (LASIK)
Bruce Rivers1, Denise S. Ryan1, Rose K. Sia1, Lamarr Peppers1,
Lorie A. Logan1, Jennifer B. Eaddy1, Joseph F. Pasternak2, Richard
Stutzman2, Samantha B. Rodgers1, Kraig S. Bower3. 1Warfighter
Refractive Surgery and Research Center, Fort Belvoir, VA;
2
Ophthalmology, Walter Reed National Military Medical Center,
Bethesda, MD; 3The Wilmer Eye Institute, Johns Hopkins University,
Baltimore, MD.
Purpose: To compare visual acuity and contrast sensitivity results
after wavefront-guided (WFG) and wavefront-optimized (WFO) PRK
and LASIK.
Methods: This was a prospective study of 213 myopic US military
personnel undergoing either PRK or LASIK randomized to either
WFG or WFO treatment. WFG surgeries were performed using the
VISX Star S4 (Abbott Medical Optics) and WFO surgeries with
the Wavelight Allegretto Wave Eye-Q (Alcon Surgical). Outcome
measures included corrected distance high contrast visual acuity
(HCVA) and small letter (20/25) contrast sensitivity (CS) measured
with the SuperVision back-illuminated letter; corrected low contrast
visual acuities (LCVA) using 5% low contrast chart under photopic
condition and 25% low contrast chart under photopic and mesopic
conditions; and night vision assessed with the 25% low contrast chart
viewed through a dark green night vision filter. Tests were performed
at preop and at 1, 3, and 6 months postop. Repeated measures
analysis of variance was used to compare the groups over time. A
p-value <0.05 was considered statistically significant.
Results: U.S military personnel aged 30.8 years ±6.8 with manifest
spherical equivalent -3.61 diopters ±1.53 participated in this study.
A statistically significant difference was seen among the treatment
groups in 5% LCVA under photopic condition (p=0.04) and 25%
LCVA under mesopic condition (p=0.02). Performance under the
follow testing conditions did not reach statistical significance:
SuperVision HCVA (p=0.63), SuperVision CS (p=0.05), 25% LCVA
under photopic condition (p=0.44) and nigh vision performance
(p=0.32).
Conclusions: Visual acuity and contrast sensitivity up to the 6
months postoperative period did not appear to have a discernible
association to the refractive surgery performed, whether the surgery
was PRK or LASIK, on either WFG or WFO excimer laser platform.
Commercial Relationships: Bruce Rivers, None; Denise S. Ryan,
None; Rose K. Sia, None; Lamarr Peppers, None; Lorie A. Logan,
None; Jennifer B. Eaddy, None; Joseph F. Pasternak, None;
Richard Stutzman, None; Samantha B. Rodgers, None; Kraig S.
Bower, None
Support: Dept of Defense W81XWH-09-2-0018
Clinical Trial: NCT 01097525
Program Number: 1526 Poster Board Number: C0165
Presentation Time: 8:30 AM–10:15 AM
Cases review of Corneal opacification after photorefractive
keratectomy (PRK).
KEESUN TAE, Junggon Cho, Jiwon Hong, Soojeong Lee. Yebon eye
center, Seoul, Republic of Korea.
Purpose: To describe the postoperative results of 3 patients with
various spectra of corneal opacification after PRK.
Methods: Three patients who had corneal opacification after PRK
were reviewed
Results: Case 1
©2014, Copyright by the Association for Research in Vision and Ophthalmology, Inc., all rights reserved. Go to iovs.org to access the version of record. For permission
to reproduce any abstract, contact the ARVO Office at [email protected].
ARVO 2014 Annual Meeting Abstracts
The first patient, a 27-year-old woman, presented with severe pain
and diffuse opacity on postoperative day 1 after PRK. After receiving
intensive antibiotic treatment for the microbial infection of the
cornea, pain was substantially alleviated. However the patient still
had a wide area of persitent epithelial defect, with grade 4 corneal
opacities persisting for more than three month in both eyes. The
patient’s best spectacle–corrected visual acuity (BSCVA)decresed
gradually. We treated the patient with antibiotic eyedrops, autologous
serum eyedrop and preservative free artificial tears. Six months
after the PRK, we performed amniotic membrane transplantation
(AMT) after removal of corneal epithelium and fibrous opacification
materials on the surface of the cornea.
Case 2
A 34-year-old woman, who underwent PRK surgery nine months
ago, experienced thick corneal opacity with decreased BSCVA.
Removal of the corneal opacifications was performed manually with
a blade. In addition, 0.01% mitomycin-C was applied on the cornea
for two minutes after removing opaque fibers. Two months after this
treatment, the patients’ visual acuity recovered to 20/20 without any
occurrence of corneal haze.
Case 3
The third patient, a 37-year-old high myopic male, had corneal
opacity after undergoing enhancement PRK surgery. In the treatment
of this patient, we decided to halt using topical steroid eyedrops
in favor of clinical observation. Corneal opacification cleared
spontaneously after four months, and visual acuity was restored to
20/20.
Conclusions: Corneal opacification after PRK usually results not
only in decreased visual acuity, but also in decreased visual quality
due to the photoactivation of some toxic substance in the eye. In
some instances, microbial infection during epithelial healing may
trigger the opacity. While in many cases it may take several months
for the opacity to clear spontaneously after PRK, the prognosis
is generally good. Nevertheless, in some cases, patients are left
with significant refractive errors, in spite of treatment efforts.
Further research to get more sophisticated understanding of corneal
opacification followed by PRK is necessary, so that better treatment
options may be available in the future.
Commercial Relationships: KEESUN TAE, None; Junggon Cho,
None; Jiwon Hong, None; Soojeong Lee, None
Program Number: 1527 Poster Board Number: C0166
Presentation Time: 8:30 AM–10:15 AM
Refractive Efficency of Transepithelial Photorefractive
Keratectomy (trans-PRK)
Cedric Ghetemme, Adina Agapie, Oualid Guechi, Anne-Laure
Jeancolas, Louis Lhuillier, Shanour Premy, Francois Ameloot, JeanMarc Perone. ophthalmology, Regional Hospital Center of MetzThionville, Metz, France.
Purpose: Evaluate the refractive results from two months onward,
had a focus group of patient who was able to benefit trans-PRK for
ametropia.
Methods: Trans-epithelial PRK, whereas regular PRK, uses laser for
the ablation of the corneal epithelium and is not operated manually.
The retrospective study includes 70 patients (129 eyes) who undergo
surgery for myopia, astigmatism and hyperopia by Trans-PRK
(Excimer Schwind Amaris 500E) between April 2012 and October
2013. The auto-refraction measures preoperative and postoperative
were realized by an auto-refractometer (Luneau L67). The study
parameters were: preoperative and final refractions after 2 months
(based on a spherical equivalent) compared with intended refraction
initially researched. For a majority of the patients, the targeted
refraction was emmetropia, excepted for the youngest myopics
patients for which the targeted refraction was +0.25 D. For fifteen
presbyopics patients, a final residual myopia between -0.50 and
-2.00D were deliberately sought at the master eye.
Results: Our study is focusing on 129 eyes from 70 patients (43
females, 27 males) with a middle age population of 38.3 ±13.7
years old. Patients presented myopia, hyperopia or astigmatism. The
ametropia population was considered as the norm, with a maximal
hyperopia of +4D and a maximal myopia of -8D. The average basis
of corrected myopia were -2.52 ±1.47D, hyperopia one’s of +2.58
±1.05D, finally astigmatism one’s 1.58± 1.09D. On all 96 eyes
intended emmetropia or intended at +0.25D, 64% (61 eyes) had
postoperative acuity of 20/20 and 98% (94 eyes) had acuity of 20/40
or better uncorrected. The mean deviation from intended correction
is 0.455± 0,39D at 2 months (in absolute value), and is not correlated
to the type of ametropia. The mean manifest refractive spherical
equivalent was ≤0.25D for 52% of the eyes (66) and ≤0.50D for 81%
of the eyes (104).
Conclusions: Treatments by transPRK are currently not well
developed, lacking adapted equipment in most of the healing centers.
Refractive results bring satisfaction with a mean deviation from
intended correction of 0.45D, regardless the initial ametropia, which
is conform and equivalent to the results after regular PRK in the
literature data. The transPRK procedure appears as a simple, fast,
uniform and non-operator-dependent method for a refractive result
which appears equivalent to the one obtained through the regular
PRK surgical intervention.
Commercial Relationships: Cedric Ghetemme, None; Adina
Agapie, None; Oualid Guechi, None; Anne-Laure Jeancolas,
None; Louis Lhuillier, None; Shanour Premy, None; Francois
Ameloot, None; Jean-Marc Perone, None
Program Number: 1528 Poster Board Number: C0167
Presentation Time: 8:30 AM–10:15 AM
Femtosecond laser flap parameters and opaque bubble layer
incidence: a novel digital analysis technique
Siddarth Rathi1, Anastasios J. Kanellopoulos1, 2, George Asimellis2.
1
Department of Ophthalmology, NUY Medical School, New York,
NY; 2LaserVision.gr Eye Institute, Athens, Greece.
Purpose: To investigate the extent and rate of incidence on opaque
bubble layer (OBL) and to determine femto-second laser assisted
corneal flap diameter accuracy and precision by a novel digital image
analysis.
Methods: Digital images from 100 flaps captured during routine
LASIK procedures with the FS200 femtosecond laser (Alcon
Surgical, Fort Worth, TX). They were objectively analyzed for flap
size (diameter) by comparing achieved vs intended (programmed)
diameter and investigated OBL incidence and extent (area). Two
groups of study were formed: group-A and group-B, of 50 flaps of
different laser flap parameters (A vs B: increased venting chimney
diameter and decreased spot separation).
Statistics were assessed using paired two-tailed t-tests, coefficient of
determination (R2), trend line linearity, bias, and plots of differences
against means.
Results: The indented flap diameters ranged in both groups from
8.00 to 9.50 mm. The achieved flap diameter was on average -0.16
mm smaller for the programmed 8.00 mm, -0.12 mm for the 8.50
mm, and +0.03 mm larger for the 9.50 mm programmed diameter.
With an average flap area 72.4±9.5 mm2, the average OBL area in
group-B was 4.1±4.3 mm2 (14.34 to 0 mm2), corresponding to a 6%
OBL-to-flap area. 30% of the flaps had zero, and 50% had OBL area
corresponding to less than 2.7% of the total flap area. In group-A,
respectively, the OBL-to-flap area was 2.9±2.3 mm2, corresponding
to a 3.5% OBL-to-flap area.
©2014, Copyright by the Association for Research in Vision and Ophthalmology, Inc., all rights reserved. Go to iovs.org to access the version of record. For permission
to reproduce any abstract, contact the ARVO Office at [email protected].
ARVO 2014 Annual Meeting Abstracts
Conclusions: The FS200 created flaps have impressive
reproducibility. Very small consistent deviations from the indented
diameter are observed. OBL incidence was, for the majority of the
flaps less than 3% of the total area in group-A (improved parameter
settings).
Examples of flaps studied from group-A and group-B showing the
different chimney parameters
Commercial Relationships: Siddarth Rathi, None; Anastasios J.
Kanellopoulos, Alcon (C), Avedro (C); George Asimellis, None
Program Number: 1529 Poster Board Number: C0168
Presentation Time: 8:30 AM–10:15 AM
Variability in thickness and diameter of corneal flap created with
a femtosecond laser
Rafael Paz-Franco, Narlly Ruíz-Quintero, Edna Ángel-Muñoz,
Leandro Linares, Talía Nieto. Cornea, APEC, Coyoacán, Mexico.
Purpose: To determinate the variability of thickness and diameter of
corneal flap programmed versus obtained with femtosecond laser.
Methods: The study design was prospective, transversal,
observational and descriptive. All patients consulting for refractive
surgery Laser Assisted in Situ Keratomileusis (LASIK), in which
the corneal flap was created using the femtosecond laser, were
selected. The thickness and diameter of corneal flap were programed
in Visumax 500Hz femtosecond laser. After three months, a single
observer measured the thickness of the corneal flap with optical
coherence tomography of anterior segment (VISANTE OCT), taking
two images along the axis from 0 to 180 degrees and making three
measurements of the thickness. The diameter of the corneal flap
was measured sing a caliper on the axis from 0 to 180 degrees. The
data analysis regarding mean values, ranges and standard deviations
were calculated with SPSS. Method comparison and evaluation were
made with Bland - Altman Medcal program. We considered clinically
significant a variation up to 10 microns in the programmed flap
versus the obtained.
Results: A total of 80 eyes from 40 patients were comprised. The
mean age of patients included were 23.7 years, (range 20–42 years,
SD 4.88). The programmed flap with Visumax 500Hz femtosecond
laser was 120 microns and the diameter of corneal flap was 7.94 mm.
The obtained flap had a mean thickness of 116.93 micron (range
100-128 microns, SD 4.86). The obtained corneal flap had a mean
diameter of 8.01 mm (7.0 – 8.2 mm, SD 0.53).
Conclusions: When creating a corneal flap, the femtosecond laser
is predictable within clinically acceptable ranges. Comparing
programmed flap versus obtained, the mean variability of thickness
was in the order of 3 microns and the diameter 0.08 mm.
Commercial Relationships: Rafael Paz-Franco, None; Narlly
Ruíz-Quintero, None; Edna Ángel-Muñoz, None; Leandro
Linares, None; Talía Nieto, None
Program Number: 1530 Poster Board Number: C0169
Presentation Time: 8:30 AM–10:15 AM
Incidence and Management of Suction Loss in Refractive
Lenticule Extraction
Kailing Yong1, Cheewai Wong1, 2, Cordelia Chan1, Donald T. Tan1, 2,
Jodhbir S. Mehta1, 2. 1Ophthalmology, Singapore National Eye Centre,
Singapore, Singapore; 2Singapore Eye Research Institute, Singapore,
Singapore.
Purpose: To describe the incidence, management and outcomes of
suction loss in refractive lenticule extraction (ReLEx).
Methods: Case series of all patients who experienced suction loss
during ReLEx in a tertiary eye hospital from 9 March 2010 to 5
August 2013. Preoperative evaluation included uncorrected and
corrected distance visual acuity, slit lamp biomicroscopy, fundoscopy,
corneal topography, ultrasound pachymetry and both manifest and
cycloplegic refraction. Patients were followed up at predetermined
time points. At each follow up visit, uncorrected distance visual
acuity (UDVA) and corrected distance visual acuity (CDVA) were
measured and all patients underwent slit lamp biomicroscopy.
Manifest refraction was performed at postoperative month 1 and 3.
Results: 340 ReLEx procedures were performed during the study
period. The overall cumulative incidence of suction loss was 3.2%.
The incidence of suction loss in each procedure was: 1.9% (3/155)
FLEx,and pSMILE, and 4.4%(8/183) SMILE. At the 3rd postoperative month, the proportion of eyes with UDVA of 20/30 or
better was 8/11 (72.7%) and 9/11 (81.8%) had spherical equivalent
within 0.5D of emmetropia. Four cases of suction loss occurred
during posterior lenticule cut, 5 during anterior lenticule cut and 2
during lamellar flap cut. In 9/11 (81.8%) cases, suction was reapplied
and the procedure was completed without any further complications.
Conclusions: Suction loss during ReLEx is relatively uncommon.
Good visual outcome can be achieved with appropriate management.
Commercial Relationships: Kailing Yong, None; Cheewai Wong,
None; Cordelia Chan, None; Donald T. Tan, None; Jodhbir S.
Mehta, None
Program Number: 1531 Poster Board Number: C0170
Presentation Time: 8:30 AM–10:15 AM
Changes in Ocular Surface and Tear Inflammatory Mediators
after Small-incision Lenticule Extraction and Femtosecond
Laser-assisted Laser in Situ Keratomileusis
Xingwu Zhong, Shaohui Gao. State Key Laboratory of
Ophthalmology, Zhongshan Ophthalmic Center, Guangzhou, China.
Purpose: To compare the effects on ocular surface and levels
of tear inflammatory mediators between small-incision lenticule
extraction(ReLEx smile) and femtosecond laser-assisted laser in situ
keratomileusis(FS-LASIK) surgery.
Methods: fiffeen subjects underwent ReLEx smile and thirty-two
subjects (32 eyes) underwent FS-LASIK were evaluated in this
prospective study. Corneal fluorescein(FL) staining, tear breakup time(TBUT), schirmer I test (SIT) and ocular surface disease
index(OSDI) were estimated. Tears were collected and assayed using
multiplex magnetic bead for interleukin-6(IL-6), tumor necrosis
factor-α
(TNF-α), nerve growth factor(NGF) and intercellular adhesion
molecule-1 (ICAM-1).
The ocular surface parameters and tear inflammatory mediators were
assessed preoperatively as well as at 1 day, 1 week,1 month and 3
months postoperatively.
Results: FL scores in ReLEx smile group were lower than that of
FS-LASIK group at 1 week postoperatively(P=0.010). The longer
TBUT in ReLEx smile group were observed than FS-LASIK at 1
month(P=0.029) and 3 months (P=0.045) after surgery. OSDI in FS-
©2014, Copyright by the Association for Research in Vision and Ophthalmology, Inc., all rights reserved. Go to iovs.org to access the version of record. For permission
to reproduce any abstract, contact the ARVO Office at [email protected].
ARVO 2014 Annual Meeting Abstracts
LASIK group were higher than ReLEx smile at 1 month (P=0.020).
The higher central corneal sensitivity showed in ReLEx smile
group at 1 week(P<0.05), 1 month(P<0.05) and 3 months(P<0.05)
postoperatively. The lower concentrations of IL-6 were detected in
ReLEx smile group than FS-LASIK group at 1 week(P=0.015) and
1 month(P=0.006) after surgery. NGF in tears of FS-LASIK group
was higher than ReLEx smile at any visit(P<0.05). There were no
obvious differences for TNF-α and ICAM-1 between two groups at
any follow-up time. In ReLEx smile group, IL-6 levels correlated
positively with OSDI (r=0.363,P=0.004), and negative correlation
was found between NGF and central corneal sensitivity. In FSLASIK group, IL-6 concentrations correlated positively with FL and
OSDI.
Conclusions: There was a more superior condition of ocular surface
for ReLEx smile than FS-LASIK at early period of postoperation.
IL-6 and NGF were associated with the severity of ocular surface
parameters after two surgeries.
Commercial Relationships: Xingwu Zhong, None; Shaohui Gao,
None
Support: This work was supported by grants from the National
Natural Science Foundation of China (81371046)
Program Number: 1532 Poster Board Number: C0171
Presentation Time: 8:30 AM–10:15 AM
Differences in the corneal biomechanical effects between Small
Incision Lenticule Extraction, Femtosecond Laser LASIK and
LASEK
Di Wu, Yan Wang. Tianjin Eye Hospital, Tianjin Medical University,
Tianjin, China.
Purpose: To investigate the biomechanical properties of the cornea
after small incision lenticule extraction (SMILE) surgery and
compare corneal biomechanical effects between SMILE, LASIK and
surface ablation.
Methods: This prospective study comprised myopic SMILE eyes
(n=37), Femto-LASIK eyes (n=34) and LASEK eyes (n=35). Corneal
hysteresis (CH), corneal resistance factor (CRF), and 37 other
biomechanical waveform parameters were quantitatively assessed
with the use of an Ocular Response Analyzer preoperatively and at
postoperative 1, 3, and 6 months.
Results: CH and CRF decreased significantly after surgery in all 3
groups (P<0.0001). In the SMILE group, the 3-month and 6-month
postoperative CH values showed a significant increase compared
with 1-month values (P<0.003), while this recovery tendency of CH
was not observed in the Femto-LASIK group and LASEK group.
The percentage change in CRF and CH were significantly greater
in the Femto-LASIK group than in the SMILE group and LASEK
group (P=0.022 and P=0.001, CRF; P=0.143 and P=0.009, CH).
Additionally, the correlation between residual stromal thickness
index and the percentage change in CRF and CH were statistically
significant in the ReLEx smile group (r=0.590, P<0.0001, CRF;
r=0.483, P=0.002), whereas no significant correlation was shown in
the Femto-LASIK group and LASEK group. The smallest percentage
change in biomechanical waveform parameters was in the LASEK
group.
Conclusions: Flap creation combined with stromal ablation had
greater effect on the cornea’s viscoelastic properties than flapless
procedures. The smallest change in biomechanical waveform
parameters was in the surface ablation group (LASEK). SMILE
caused a significantly more predictable change in corneal
biomechanics, which correlated strongly with RST index, than the
change with Femto-LASIK and LASEK.
Commercial Relationships: Di Wu, None; Yan Wang, None
Support: National Natural Science Foundation of China (Grant No.
81170873)
Program Number: 1533 Poster Board Number: C0172
Presentation Time: 8:30 AM–10:15 AM
Enhanced Topical Delivery of a Novel Loteprednol Etabonate
Ophthalmic Formulation
Lisa Schopf, Alexey Popov, Elizabeth M. Enlow, James R. Bourassa,
Hongming R. Chen. Preclinical Development, Kala Pharmaceuticals,
Waltham, MA.
Purpose: To improve topical drug delivery to the eye, Kala has
developed mucus penetrating particle (MPP) technology that
facilitates drug penetration through pre-corneal mucus layer,
providing superior delivery of drug to ocular tissues. The objective
of this work was to evaluate a novel MPP formulation of loteprednol
etabonate (LE-MPP).
Methods: Two in vivo distribution studies were conducted in rabbits
to determine the ocular/systemic pharmacokinetic (PK) profiles of LE
following topical administration of various LE-MPP concentrations.
An additional distribution study was performed to compare LE-MPP
1.0% to commercially available Lotemax® (ophthalmic suspension)
0.5%. PK analysis was performed using WinNonlin software. To
support the clinical evaluation of LE-MPP, a 28-day rabbit ocular
toxicity study was conducted and standard ophthalmology, body
weight, clinical signs, and histopathology of all ocular-related tissues
and adrenal glands were evaluated.
Results: The dose-dependent concentration-time profiles of LE in
aqueous humor (AH) revealed a proportional increase, as area under
the curve, with doses from 0.4 to 1.0%, while the peak concentration
plateaued at 0.6% with no further increase seen at 1.0%. The PK
profiles of LE-MPP 1.0% drug product and Lotemax were compared
in the AH, cornea, retina and plasma. The enhancement in LE
exposure in all tissues was most pronounced over the first 3 hours
after a single topical dose of LE-MPP as compared to Lotemax. The
same tissues were examined after topical dosing of LE-MPP 1.0% or
0.25%. This analysis revealed that an increase in dose concentration
increased exposure in the tissues assessed. The administration of
LE-MPP 1.0% drug product to rabbits via ocular instillation four
times daily for 28 days was well-tolerated and resulted in no test
article-related observations except a mild decrease in body weight
and body weight gain, a decrease in absolute lymphocyte count,
adrenal cortical and hair follicle atrophy, effects that are expected for
a corticosteroid and similar to those observed with Lotemax.
Conclusions: The PK results support the premise that the MPP
technology can be used to enhance ocular exposure of topically
applied therapeutic agents. The administration of LE-MPP 1.0% drug
product was well-tolerated and the observed effects were considered
secondary to the expected pharmacology of a corticosteroid and
similar to those previously reported for Lotemax.
Commercial Relationships: Lisa Schopf, Kala Pharmaceuticals (E);
Alexey Popov, Kala Pharmaceuticals (E); Elizabeth M. Enlow, Kala
Pharmaceuticals (E); James R. Bourassa, Kala Pharmaceuticals (E);
Hongming R. Chen, Kala Pharmaceuticals (E)
Program Number: 1534 Poster Board Number: C0173
Presentation Time: 8:30 AM–10:15 AM
Visual outcomes and corneal asphericity effects of Kerarings
implantation for keratoconus treatment
Samantha Bonnel, Marouen Berguiga, Naima Saib, Jean-Remi
Fenolland, Damien Sendon, Camille Rambaud, Mélanie Abrieu,
Françoise Froussart-Maille, Pascale Crepy, Jean-Claude RigalSastourne. ophtalmologie, HIA PERCY, Clamart Cedex, France.
©2014, Copyright by the Association for Research in Vision and Ophthalmology, Inc., all rights reserved. Go to iovs.org to access the version of record. For permission
to reproduce any abstract, contact the ARVO Office at [email protected].
ARVO 2014 Annual Meeting Abstracts
Purpose: To evaluate changes induced by Kerarings implantation in
corneal asphericity, keratometry and visual outcomes.
Methods: This study is a retrospective clinical trial, including 40
eyes of 31 keratoconus patients operated with Keraring between
November 2009 and December 2012. Uncorrected visual activity
(UCVA) and best spectacle-corrected visual acuity (BSCVA)
assessment, keratometry and asphericity (Q factor at 20 degrees)
measurement using Pentacam HR® was performed before and
six months after Kerarings implantation by one experimented
surgeon and according to the manufacturer nomogram. All clinical
examinations were performed in a standardized manner by an
independent examiner. The analyse of the visual acuity (more or less
than a line) enables to differentiate two groups of “good” and “bad”
responders. Biostat TGV, a freeware was used for statistical analysis.
The Wilcoxon signed rank test was applied to assess the significance
of difference between pre- and post-operative data and the WilcoxonMann Whitney test to assess the group comparisons. The Spearman
test was used to assess the correlation between different clinical
variables. The significance level was defined as p≤0.05.
Results: Table 1 shows preoperative and postoperative results.
We found a gain of 3.6 lines for UCVA (0.21 preoperatively to
0.46 postoperatively), 1.1 lines for BSCVA (0.59 to 0.73) and a
decrease in Kmean of 1.4 D (p≤0.001). The Q factor is significantly
improved, from -0.63 to -0.33 (p=0.002). Six months after Ferrara
rings implantation, UCVA has gained more than one line in 70% of
eyes, less than one line in 2,5% of eyes, was stable in 25% of eyes
and decreased in 2.5%. On BSCVA, 47.5% of eyes gained more than
one line, 22.5% gained less than one line 17.5% were stable and only
12.5% decreased their vision. We found no significant difference
between preoperative parameters of “good” and “bad” responders
groups. Before surgery, BSCVA is correlated to the Q factor (p=0.02)
and after surgery, both UCVA and Kmax are correlated to the Q
factor (respectively p=0.02 and p=0.00). But the Kmax variation and
the UCVA or BSCVA gains are not correlated.
Conclusions: Kerarings have good visual outcomes and improve
mean keratometry and asphericity. But there are no predictive factors
of the magnitude of the visual gain and no correlation between this
gain and the asphericity variation.
Commercial Relationships: Samantha Bonnel, None; Marouen
Berguiga, None; Naima Saib, None; Jean-Remi Fenolland, None;
Damien Sendon, None; Camille Rambaud, None; Mélanie Abrieu,
None; Françoise Froussart-Maille, None; Pascale Crepy, None;
Jean-Claude Rigal-Sastourne, None
Program Number: 1535 Poster Board Number: C0174
Presentation Time: 8:30 AM–10:15 AM
Tomographic Analysis and Outcomes of Refractive Surgery
Patients with Posterior Embryotoxon
Edward Trudo. 1Ophthalmology, Storm Eye Institute MUSC,
Charleston, SC; 2Ophthalmology, Warfighter Refractive Surgery
Research Center, Fort Belvoir, VA.
Purpose: To quantify the atypical tomographic features of patients
with posterior embryotoxon of the cornea and review impact on
refractive surgery outcomes.
Methods: Retrospective analysis of 1015 consecutive refractive
surgery patient records wherein all atypical examination and
tomographic features were prospectively monitored as part of a
quality improvement process. Eighteen (18) patients were identified
as having posterior embryotoxon in one or both eyes. Nine (9) of
these patients met the inclusion criteria of available preoperative
Scheimpflug images and seven (7) patients met the requirement of at
least 3 months of postoperative data.
Results: The average patient age was 22.1 years. The mean
preoperative manifest refraction spherical equivalent was -4.01, the
mean cornea pachymetry at the thinnest point was 556.72 microns,
the mean back surface elevation (BSE) of clinically affected eyes was
19.85. The Corneal Thickness Spatial Profile (CTSP) was steeper
than normal in 16/18 (89%) eyes. The I-S ratio mean was 0.76. None
of the patients showed significant anterior surface elevation (mean =
3.72) or significant corneal thinning compared to the pupil position
pachymetry (mean = 1.722 microns) indicative of ectasia risk. The
postoperative uncorrected visual acuity mean was 20/16.4 (range
20/10-20/20) with 3-12 months of data.
Conclusions: Patients who present for refractive surgery evaluation
and show greater than normal BSE and steeper CTSP should be
evaluated for posterior embryotoxon to differentiate these patients
from form fruste keratoconus. The anatomic changes of posterior
embryotoxon may show a greater BSE and steeper CTSP on best fit
sphere. Careful analysis of the I-S ratio, thinnest pachymetry change,
and front surface elevation is helpful is differentiating these patients
from those at risk for ectasia. Short term refractive surgery results
indicate no unfavorable outcomes, irregular healing, or unexpected
astigmatism.
Commercial Relationships: Edward Trudo, None
Support: Research to Prevent Blindness
Program Number: 1536 Poster Board Number: C0175
Presentation Time: 8:30 AM–10:15 AM
Variability of ocular reference center location in normal eyes
Vinod Maseedupally, Daniel Meoli, Bendy Nguyen, Pauline Kang,
Helen A. Swarbrick. School of Optometry and Vision Science,
University of New South Wales, Sydney, NSW, Australia.
Purpose: To determine the variability in the location of various
ocular reference centers.
Methods: Ocular reference center data were collected from right
eyes of 20 young normal subjects aged between 18 and 27 years. The
reference centers included the geometric center (GC), corneal apex
(CA), entrance pupil center (EPC) and corneal sighting center (CSC).
Corneal topographic maps captured using the Medmont E300 corneal
topographer (Melbourne, Australia) were used to locate GC, CA, and
EPC relative to the map’s default center which is the vertex normal
(VN). The GC was defined as the center of a best-fit ellipse fitted
to the limbus. The CA was defined as the centroid of the steepest
corneal portion on the tangential power map. The pupil center values
as determined by the topographer were considered as the EPC. To
determine CSC location, angle lambda was measured along the
horizontal meridian only using a synoptophore (Synoptometer,
©2014, Copyright by the Association for Research in Vision and Ophthalmology, Inc., all rights reserved. Go to iovs.org to access the version of record. For permission
to reproduce any abstract, contact the ARVO Office at [email protected].
ARVO 2014 Annual Meeting Abstracts
Oculus, Germany) and the angle values were converted to millimeters
to give the distance between EPC and CSC at the corneal plane.
Results: The GC was located 0.33 ± 0.13 mm (range 0.12 – 0.64
mm) from the VN. All eyes showed the location of GC temporal
to VN, of which the majority (16 eyes - 80%) were also located
inferiorly. The CA was located at 0.84 ± 0.64 mm (0.21 – 2.25 mm)
from the VN. The majority showed a temporal (15 eyes - 75%) and
superior (11 eyes – 55%) location of CA. The EPC was located 0.18
± 0.12 mm (0 - 0.46 mm) from the VN, of which the majority were
located superiorly (17 eyes - 85%), and temporally (13 eyes - 65%).
The CSC was located at 0.31 ± 0.15 mm (0 - 0.60 mm) nasal to the
EPC.
Conclusions: Among various ocular reference center locations, the
EPC was least variable and CA was most variable. Since CA is the
reference center that governs the centration of rigid contact lenses,
it is likely that lenses may tend to decenter temporally. However,
decentration is likely to vary significantly between individuals. The
variability in the location of CSC also highlights the importance
of centering corneal reshaping procedures such as laser refractive
surgery and orthokeratology to optimize visual outcomes and enhance
patient satisfaction.
Commercial Relationships: Vinod Maseedupally, Bausch + Lomb
Boston (F), BE Enterprises (F), Capricornia Contact Lens Pty Ltd
(F); Daniel Meoli, None; Bendy Nguyen, None; Pauline Kang,
Bausch + Lomb Boston (F), BE Enterprises (F), Capricornia Contact
Lens Pty Ltd (F); Helen A. Swarbrick, Bausch + Lomb Boston (F),
BE Enterprises (F), Capricornia Contact Lens Pty Ltd (F)
Support: Australian Government ARC Linkage Scheme
Program Number: 1537 Poster Board Number: C0176
Presentation Time: 8:30 AM–10:15 AM
Effect of the induction of cyclopegia on corneal topography
Thomas D. Raymond, James Copland, Steve Farrer, Wei Xiong,
Daniel R. Neal. R&D, Abbott Medical Optics, Albuquerque, NM.
Purpose: This retrospective study investigates the effect of
cycloplegia on keratometry and corneal topography. Cycloplegic
drugs are commonly applied to enable measurement of wavefront
over large pupils for LASIK planning. In a previous study Zhou
et al1 found no significant effects to corneal aberrations using a
Placido disk topographer. This study revisits this topic with particular
attention to keratometry and keratometric angle using a spot based
topographer.
Methods: Wavefront refraction, wavefront aberration, keratometry,
corneal topography and pupil diameter measurements were taken
on 76 eyes of 44 subjects with virgin eyes. The measurements were
acquired with the iDesign combined instrument before and after the
application of 1 drop of cyclopentolate 1% at least 30 minutes prior
to induce cycloplegia. In contrast to the previous studies which used
Placido based corneal topography the instrument used here measures
corneal topography with the iDesign spot based corneal topographer
with coverage to the corneal vertex. Keratometry magnitudes, K1 and
K2(steep) and steep meridian axis (K2 Angle) were analyzed using
a matched pairs analysis as were the wavefront aberrations through
fourth order.
Results: The mean pupil diameter increased from 6.31 ± 0.85(1σ)
mm to 7.66 ± 0.62(1σ) upon application of the cycloplegic drug; the
average matched pairs difference was +1.57 ± 0.07 mm. The matched
pairs analysis for K2-K1 and K2 Axis are shown in Figure 1. The
astigmatism magnitude mean difference was -0.036D ± 0.016(1σ)
D which was statistically significant with a P value of 0.01. The
axis mean difference was -0.68 ± 1.98 (1σ) degrees which was not
statistically significant (P value 0.36).
Conclusions: The use of cycloplegic drugs has a statistically
significant effect on corneal astigmatism, but the effect is not
clinically significant. The astigmatism axis was found to be
unchanged. We conclude that the use of cycloplegic drugs did not
significantly alter the corneal astigmatism.
1. F. Zhou, L.N. Thibos and D.T. Miller, The effect of cycloplegic
drugs on corneal and whole–eye aberrations of the human eye, Invest
Ophthalmol Vis Sci 2004;45: E-Abstract 2833; © 2004 ARVO.
All authors are employees of Abbott Medical Optics.
Figure 1 Matched pairs analyses for corneal astigmatism magnitude
and axis.
Commercial Relationships: Thomas D. Raymond, Abbott Medical
Optics (E), Abbott Medical Optics (P); James Copland, Abbott
Medical Optics (E), Abbott Medical Optics (P); Steve Farrer, Abbott
Medical Optics (E), Abbott Medical Optics (P); Wei Xiong, Abbott
Medical Optics (E), Abbott Medical Optics (P); Daniel R. Neal,
Abbott Medical Optics (E), Abbott Medical Optics (P)
Program Number: 1538 Poster Board Number: C0177
Presentation Time: 8:30 AM–10:15 AM
Corneal Thickness in Individuals with Myopia
RAFAEL F. Kobayashi, Maria Flavia Ribeiro, Flavio E. Hirai, Eliane
Nakano, Claudia Francesconi, Mauro Campos. Ophtalmology,
UNIFESP, SAO PAULO, Brazil.
Purpose: To evaluate corneal thickness across corneal meridians in
individuals with myopia
Methods: One hundred and fifteen individuals had both eyes
evaluated. Examinations included refraction and corneal thickness
measured by Pentacam and Oculyzer.
Myopes were categorized as low (spherical equivalent between zero
and -3.00); moderate (-3.00 to -6.00); and severe (higher than -6.00).
Corneal thickness were evaluated 2, 4 and 6mm from the central
corneal thickness in the axis of 0,45,90,135,180, 225, 270 and 315
degrees. (Figure 1)
Corneal thickness were compared across groups and corneal
meridians with repeated measures ANOVA to adjust for the
correlation between eyes.
All p-values < 0.05 were considered statistically significant.
Results: There is no statistically significant difference in corneal
thickness between low, moderate and severe myopes in each axis.
Corneal thickness on the inferior meridians (225, 270 and 315
degrees) are thinner compared to the superior meridians (45, 90 and
135 degrees) for low and moderate myopes (p<0,05).
©2014, Copyright by the Association for Research in Vision and Ophthalmology, Inc., all rights reserved. Go to iovs.org to access the version of record. For permission
to reproduce any abstract, contact the ARVO Office at [email protected].
ARVO 2014 Annual Meeting Abstracts
Conclusions: Corneal thickness did not differ between different
levels of myopia. However, the pachymetric map showed thinner
corneas in the inferior meridians when compared to pachimetry in the
upper half of the cornea.
Commercial Relationships: RAFAEL F. Kobayashi, None; Maria
Flavia Ribeiro, None; Flavio E. Hirai, None; Eliane Nakano,
None; Claudia Francesconi, None; Mauro Campos, None
Program Number: 1539 Poster Board Number: C0178
Presentation Time: 8:30 AM–10:15 AM
A Physics Model for Intraocular Pressure Increase Induced by
Patient Interface
Hong Fu. R&D Engineering, Abbott Medical Optics, Santa Ana, CA.
Purpose: A patient interface is an opto-mechanic device used in a
femtosecond laser eye surgery. It serves two functions: to stabilize
the eye and to couple the laser into the eye to form a sharp focus in
the surgical region. It is well known that docking a patient interface
onto the eye causes a side effect – an increase in intraocular pressure
(IOP). The purpose of this work is to develop a physics model to
describe the key mechanisms that cause the IOP increase.
Methods: We established a physics model that includes three factors
that are known to cause IOP increase: the suction, applanation, and
load force. We made two assumptions: first, the eyeball is a sphere
filled with incompressible fluid, and second, the eyeball surface is
elastic with a uniform Young’s modulus. Under these assumptions,
any deformation made to the eyeball, which can be induced by the
suction, applanation, or load force, will result in a stretch of the
eyeball surface to cause increase in the surface strain. By calculating
the potential energy of the elastically stretched eyeball surface, we
can derive the IOP change.
Results: We derived that Δ(IOP) ≈ α (ΔVS + ΔVA + ΔVL), where
Δ(IOP) is the IOP change, α is a constant proportional to the Young’s
modulus and a geometric factor of the eyeball, ΔVS, ΔVA, and
ΔVL are the volumetric deformations associated to the suction,
applanation, and load force, respectively, which can be evaluated
for given patent interface and docking parameters. Comparing with
the pig eye IOP change data measured at various docking steps, we
estimated that α ≈ 0.3 – 0.7mmHg/mm^3 for pig eyes. Using this
model, we calculated Δ(IOP) for flat and curved patient interfaces
as functions of glass-cornea contacting diameter for different radii
of curvature. Without knowing the specific value of the proportional
constant α, the model explains correctly the signs of Δ(IOP) at
various docking steps, and points out the root causes for IOP increase
as induced by each of the three sources.
Conclusions: We developed a physics model to describe the
mechanisms for IOP increase induced by a patient interface. It
explains why IOP changes the way as observed in various docking
steps, and provides guidelines to the design of a patient interface with
minimum IOP increase.
Commercial Relationships: Hong Fu, Abbott Medical Optics (E)
Program Number: 1540 Poster Board Number: C0179
Presentation Time: 8:30 AM–10:15 AM
Results of Toric ICL Phakic lens implantation at Fundación
Hospital Nuestra Señora de la Luz, IAP
Juan Antonio De la Campa, Regina Velasco, Oscar Baca, Alejandro
Babayan, Cristina Pacheco Del Valle, Elisa D. Alegria, Oscar
Fernandez. Fndtn Hosp Nuestra Senora de la Luz, Mexico, Mexico.
Purpose: To describe the results of the Toric ICL Phakic lens
implantation and to report the complications in a case series study at
the Fundación Hospital Nuestra Señora de la Luz, IAP.
Methods: Descriptive case serial study design of patients subjected
to Toric ICL V4c model for the correction of myopic astigmatism. We
included patients of 18 years or older, who met the following criteria:
refractive stability, endothelial cell count more than 2,000 cels/
mm2, open angle in 4 quadrants, anterior chamber depth more than
3 mm and that were excluded to perform Excimer laser refractive
surgery due a to high refractive error and thin cornea. We measured
preoperative uncorrected visual acuity (UCVA), best spectacle
corrected visual acuity (BSCVA), manifest and cycloplegic refraction,
intraocular pressure, gonioscopy, corneal topography (Orbscan IIz),
anterior chamber depth (OCT Visante) and specular microscopy;
all this data were also obtained at 6 months postoperative. We also
measured the postoperative vault with OCT Visante.
Results: Eight eyes were enrolled in the study. The mean
preoperative: refractive error in terms of spherical equivalent (SE)
was -13.6 D (-7.25 D to -18.00 D), uncorrected visual acuity 1.37
logMAR, intraocular pressure 13.75 mmHg and endothelial density
was 2705 cels/mm2. The mean postoperative: SE was -1.28 D (+0.25
to -2.50 D), uncorrected visual acuity was 0.16 logMAR, intraocular
pressure 16.2 mmHg (13 to 18 mmHg) and endothelial density was
2702 cels/mm2. The mean vault presented in the patients was 0.55
mm (0.42 mm to 0.86 mm). Seventy five percent of the eyes included
reached a visual acuity of 0.30 logMAR or more. None patient lost
a line of vision compared with the preoperative and postoperative
BCVA. The most common complication was the increase in
intraocular pressure.
Conclusions: In our series, as previously described, the toric ICL
lens implantation was an effective method to correct moderate to high
myopia and we did not experience any major complication.
Commercial Relationships: Juan Antonio De la Campa, None;
Regina Velasco, None; Oscar Baca, None; Alejandro Babayan,
None; Cristina Pacheco Del Valle, None; Elisa D. Alegria, None;
Oscar Fernandez, None
Program Number: 1541 Poster Board Number: C0180
Presentation Time: 8:30 AM–10:15 AM
PresbyLASIK treatment for correcting presbyopia in hyperopic
eyes
Alexandra Abdala, Verónica Castrillón, Clara Lopez de Mesa,
Angela M. Gutiérrez. Cornea and Refractive Surgery, Clínica
Barraquer, Bogotá, Colombia.
©2014, Copyright by the Association for Research in Vision and Ophthalmology, Inc., all rights reserved. Go to iovs.org to access the version of record. For permission
to reproduce any abstract, contact the ARVO Office at [email protected].
ARVO 2014 Annual Meeting Abstracts
Purpose: To evaluate binocular outcomes using central presbylasik
technique in hyperopic patients for the treatment of presbyopia.
Methods: A retrospective longitudinal study was performed at the
Clínica Barraquer, Bogotá - Colombia. Forty hypermetropic patients
(80 eyes) underwent central Presbylasik treatment with PresbyMAX
software developed by Schwind eye-tech-solutions and were assessed
10 days (n=80, 100%) and 90 days postoperatively (n=50, 62.5%).
The remaining 30 patients did not attend the respective follow-up.
Average patient age was 53 ± 5 years and mean preoperative manifest
refractive spherical equivalent (MRSE) +1.45 ± 0.97 diopters (D).
Mean preop uncorrected distance visual acuity (UDVA) was 0.45 ±
0.28 LogMAR. Preoperative uncorrected near visual acuity (UNVA)
was investigated as reading speed and presented in LogRAD. The
mean addition corrected was +2.38 ± 0.34 D with a UNVA of >0.48
LogRAD. Data was analyzed with the statistic program IBM SPSS
V. 21.
Results: Ninety days after the refractive treatment the mean
postoperative MRSE was -0.46±0.66 D (p<0.001) with an average
UDVA of 0.22 ± 0.16 LogMAR. The mean postoperative UNVA at
the 10 days follow-up was 0.09 ± 0.10 LogRAD and 0.16 ± 0.16
LogRAD at the 90 days follow-up (p=0.005).
Patients gained on average 1.41 ± 3.82 lines in UDVA at the 10
days follow-up (57.5%), which increased to 2.44 ± 3.78 lines at the
90-days follow-up (66.0%). The loss of lines of UDVA in the first
postoperative control was 27.5%, decreasing to 22.0% at the last
follow-up.
When analyzing the change of corneal aberrations between
preoperative and postoperative results, there was a significant change
in positive spherical aberration toward negative spherical aberrations.
A statistical significance modification in coma was also observed (p
<001).
There was not a significant change in the cylinder, distance best
corrected visual acuity (CDVA) and corrected near visual acuity
(NBCVA).
Conclusions: In conclusion, PresbyMAX can be a therapeutic
treatment option for correcting presbyopia and hyperopia.
Patient selection is essential to achieve good results. Although an
improvement of near and distance uncorrected visual acuity was
observed, further postoperative controls and investigation is required
to evaluate long-term results.
Commercial Relationships: Alexandra Abdala, None; Verónica
Castrillón, None; Clara Lopez de Mesa, None; Angela M.
Gutiérrez, None
Program Number: 1542 Poster Board Number: C0181
Presentation Time: 8:30 AM–10:15 AM
Development and validation of a near vision questionnaire for
assessment of presbyopic surgical correction
Corina van de Pol1, Lisa J. Keay2, Ling Lin1, Wellentina Greer1,
Robin L. Chalmers3. 1AcuFocus, Inc., Irvine, CA; 2Injury Division,
The George Institute for Global Health, Sydney, NSW, Australia;
3
Clinical Trial Consultant, Atlanta, GA.
Purpose: To develop and validate a questionnaire to assess near and
distance vision, symptoms and satisfaction after surgical correction of
presbyopia.
Methods: The AcuFocus Corneal Inlay Presbyopic Questionnaire
(ACIPQ) was developed using FDA Patient-Reported Outcomes
guidance, the U.S. Navy Refractive Questionnaire and applicable
NEI RQL 42 questions. Content and construct validity and reliability
were established through expert and subject review of a pilot survey.
The 46-item ACIPQ was administered to 507 subjects in the US IDE
study of the KAMRA corneal inlay preoperatively and at 3, 6, 12, 18,
24, 30 and 36 months postoperatively. Near items included ratings
for how easy it is to see at near for 6 good lighting and 6 dim lighting
tasks. Validation of 12 near vision items on the ACIPQ included
Rasch modeling (6 month), repeatability at 6 and 12 months, and test
of responsiveness to improvement in near vision (all visits).
Results: The 7 point likert response scale for the near items
demonstrated ordered thresholds on the category probability curve.
The near items fit the Rasch model: reliability measures were
acceptable, with person reliability = 0.96, item reliability = 1.00 and
person separation of 5.0, and the 12 near vision items demonstrated
unidimensionality. The questionnaire was well targeted (item-person
separation 0.48 logits). Sum score for the near tasks improved by
26 points postoperatively from 21.7±12.1 at pre-op to 47.9±14.9 at
6 months (Rasch person scores rescaled to 0-100 scale, p<0.001)
and reflected the significant improvement in unaided near vision
(UCNVA) measured in the trial (25.9±3.8 to 40.3±7.3 letters,
p<0.0001). There was a strong correlation between UCNVA and
Rasch score for near tasks (R2 = 0.44), establishing responsiveness
of the ACIPQ. The overall score for ease of near vision was stable
across all postoperative visits (ANOVA, p>0.05). Assuming stability,
the repeatability of the combined near vision score was assessed
using 6 and 12 months data which showed good repeatability
(Cronhbach’s Alpha 0.86).
Conclusions: The ACIPQ questionnaire assessing presbyopic
correction with the KAMRA corneal inlay appears to be a valid
measure of subjective near vision and reflects the significant
improvement in near visual acuity. The near task items conform to
the Rasch model, are well targeted to the study population and show
good discrimination.
Commercial Relationships: Corina van de Pol, AcuFocus, Inc.
(E); Lisa J. Keay, AcuFocus, Inc. (C); Ling Lin, AcuFocus, Inc.
(E); Wellentina Greer, AcuFocus, Inc. (E); Robin L. Chalmers,
AcuFocus, Inc. (C)
Clinical Trial: NCT00819299
Program Number: 1543 Poster Board Number: C0182
Presentation Time: 8:30 AM–10:15 AM
“Complications associated with placement of phakic intraocular
lens
Pablo D. Urzua, Jesus Jimenez-Roman, Magdalena García-Huerta,
Jesus Jimenez-Arroyo, Mariana Escalante-Castañon, Jorge OzornoZarate. Glaucoma, Asociación para Evitar la Ceguera en México,
México D.F., Mexico.
Purpose: To determine the main complications of phakic lenses
placement and the incidence of withdrawal of phakic intraocular lens
( PIOL ) secondary to them.
Methods: A retrospective cohort study was conducted, inlcuding
patients with phakic intraocular lens removal associated with
complications, obtaining a sample of 65 eyes in 60 patients. We
measured and compared each visual capacity and intraocular pressure
(IOP) before, during and after the placement of PIOL, the endothelial
cell density was measured only prior to placement and prior to
removal of PIOL . The results were analyzed using the t student
method.
Results: The average age of PIOL placement was 31.06 years old (
± 6.8), being predominant in females with 64.6 %.The most common
type of lens asociated with complications was the PIOL artisan with
86%, followed by the PIOL ICL with 9.23 %. The average power
of PIOL withdrew was -14.9 (± 3.85). The associated complications
were presented in the following order: dislocation or subluxation (
56.92 %), corneal decompensation ( 21.53 % ), cataract ( 16.92 %
), ocular hypertension or glaucoma ( 3%) and decreased endothelial
count ( 1.5 % ) .The post implant IOL IOP increased in 1.5mmHg (P:
0.014) . The posterior retirement IOL IOP was not changed prior to
©2014, Copyright by the Association for Research in Vision and Ophthalmology, Inc., all rights reserved. Go to iovs.org to access the version of record. For permission
to reproduce any abstract, contact the ARVO Office at [email protected].
ARVO 2014 Annual Meeting Abstracts
the withdrawal of the phakic IOL. Endothelial count was significantly
lower than prior to the implementation thereof ( 2581 ± 314 vs 1249
± 508) P : 0.001. The average latency for complication was 5.8 ± 2.6
years.
Conclusions: The incidence of withdrawal pIOL asociated with
complications is 10.5%, being the most frequent complication
associated subluxation of the same. We recomend the use of the ICL
PIOL in which the fewest complications occurred. However studies
that prove his long-term safety are needed.
Commercial Relationships: Pablo D. Urzua, None; Jesus JimenezRoman, None; Magdalena García-Huerta, None; Jesus JimenezArroyo, None; Mariana Escalante-Castañon, None; Jorge
Ozorno-Zarate, None
Program Number: 1544 Poster Board Number: C0183
Presentation Time: 8:30 AM–10:15 AM
Effects of a Femtosecond Laser Used During a Cataract
Procedure on a Corneal Inlay
Robert Rivera1, 2, Steve Linn1, Phillip Hoopes1, Yari Mitchell2.
1
Hoopes Vision, Draper, UT; 2AcuFocus, Irvine, CA.
Purpose: To investigate the interaction of two different femtosecond
lasers used for Laser-Assisted Cataract Surgery (LACS) on an
implanted corneal inlay and targeted ocular tissues
Methods: Six KAMRA corneal inlays (AcuFocus, Irvine, CA)
were implanted into femtosecond laser created pockets in six
porcine eyes. The iFS laser (Abbott Medical Optics, Inc, Santa Ana,
CA) and a mask were used to create intrastromal pockets at three
different depths: 100, 200 and 300 microns. The eyes were split
into two groups; Group 1 was treated with the Catalys Precision
Laser System (Abbott Medical Optics, Inc, Sunnyvale, CA), and
Group 2 was treated with the LenSx (Alcon, Inc., Fort Worth, TX)
femtosecond laser. Each group had 3 eyes, 1 per inlay implantation
depth. Lens fragmentation and capsulorhexis were performed on
all eyes with each laser. Arcuate incisions were created in one of
the eyes in Group 1, over an inlay implanted at 100 microns. After
laser phacoemulsification, each eye was assessed under a surgical
microscope. The cornea and inlay were inspected and then removed
to allow visualization of treatment of the crystalline lens and anterior
capsule.
Results: The inlay did not appear to interfere with creation of
corneal arcuate incisions. In all cases, the inlay created an optical
shadow visible on OCT, behind which laser energy was prevented
from reaching target tissues. Anterior capsular treatment appeared
unaffected. Crystalline lens fragmentation was observed in all
cases. For the eyes treated with the Catalys laser, crystalline lens
fragmentation was noted centrally and peripheral to the inlay. No
lens fragmentation peripheral to the inlay outer edge was found in
LenSx treated eyes. Following all procedures, the inlays appeared to
be intact under inspection at the microscope. Further analysis of the
inlays using SEM will be performed.
Conclusions: Femtosecond laser treatment with two cataract lasers
used in this study does not appear to affect the KAMRA corneal
inlay. Corneal arcuate incisions, capsulorhexis and lens fragmentation
are possible in the presence of the inlay, but differences in tissue
treatment are observed between both lasers.
Commercial Relationships: Robert Rivera, AcuFocus (C); Steve
Linn, None; Phillip Hoopes, None; Yari Mitchell, AcuFocus (E)
Program Number: 1545 Poster Board Number: C0184
Presentation Time: 8:30 AM–10:15 AM
The Effect of Pupil Size and Decentration from Pupil Center on
Visual Outcomes after Corneal Inlay Surgery for Presbyopia
Adam J. Roy1, Keith Holliday1, Tonya Porter1, Maggie Young1, Alan
J. Lang1, Edna Favela1, Arturo Chayet2, Enrique Barragan3, Sandra
Gomez3. 1R & D, ReVision Optics, Inc, Lake Forest, CA; 2Codet
Vision Institute, Tijuana, Mexico; 3Laser Ocular Hidalgo, Monterrey,
Mexico.
Purpose: To investigate the effect of preoperative pupil size and
accuracy of centration on the pupil center on the postoperative vision
of patients implanted with a hydrogel corneal inlay (Raindrop® Near
Vision Inlay*, ReVision Optics, Lake Forest, CA) designed to correct
poor near and intermediate vision in presbyopes.
*CAUTION: Investigational device. Limited by Federal (United
States) law to investigational use.
Methods: 249 presbyopic subjects were implanted with a hydrogel
corneal inlay in the non-dominant eye beneath a femtosecond flap.
The meniscus shape of the inlay is designed to change the curvature
of the anterior cornea to progressively increase refractive power from
the pupil center. Patients were a mix of emmetropes, myopes and
hyperopes, some of whom underwent a concurrent LASIK treatment
to correct distance vision. Mesopic and photopic pupil sizes were
recorded preoperatively, and wavefront aberrometry determined
inlay position postoperatively. Visual performance was evaluated via
uncorrected visual acuity (UVA) as measured using an Optec 6500
vision analyzer and by the unaided ability to perform common tasks
under good and dim lighting as indicated by questionnaire responses.
Statistical analyses were conducted to determine the impact of pupil
size and centration on these visual outcomes after inlay implantation.
Results: 1 year after surgery, 78% of all visual tasks could be
‘Easily’ performed in dim lighting without correction, compared
to 43% preoperatively. Patients with larger preoperative mesopic
pupils performed better, and this difference was most noticeable for
intermediate (p = 2 x 10-7) and distance (p = 2 x 10-8) tasks. At 1
month postoperative, 88% of inlays were within 0.5 mm radius of
the targeted pupil center, and 98% were within 1.0 mm radius. The
244 patients within this 1.0 mm radius region had mean monocular
UNVA 0.08, UIVA 0.14, and UDVA 0.17 logMAR and this was not
associated with the level of inlay decentration (UNVA p = 0.9, UIVA
p = 0.9, UDVA p = 0.3).
Conclusions: Preoperative mesopic pupil size is a factor associated
with the ability to perform visual tasks after surgery, in particular
larger pupils improve intermediate and distance task ability. Inlay
centration, within 1 mm of target, is not a factor associated with
visual acuity or visual performance.
Commercial Relationships: Adam J. Roy, ReVision Optics, Inc.
(E); Keith Holliday, ReVision Optics, Inc. (E); Tonya Porter,
ReVision Optics, Inc. (E); Maggie Young, ReVision Optics, Inc. (E);
Alan J. Lang, ReVision Optics, Inc. (E); Edna Favela, ReVision
Optics, Inc. (E); Arturo Chayet, Codet Vision Institute (C); Enrique
Barragan, Laser Ocular Hidalgo (C); Sandra Gomez, Laser Ocular
Hidalgo (C)
Program Number: 1546 Poster Board Number: C0185
Presentation Time: 8:30 AM–10:15 AM
Range of Vision With Near Center Hydrogel Corneal Inlay in
Presbyopic Subjects
Alan J. Lang, Adam J. Roy, Keith Holliday, Tonya Porter, Maggie
Young. R & D, ReVision Optics, Lake Forest, CA.
Purpose: To understand why presbyopic patients with a broad range
of pre-operative refractions can be treated using a single, near-
©2014, Copyright by the Association for Research in Vision and Ophthalmology, Inc., all rights reserved. Go to iovs.org to access the version of record. For permission
to reproduce any abstract, contact the ARVO Office at [email protected].
ARVO 2014 Annual Meeting Abstracts
center, design of intracorneal inlay (Raindrop® Near Vision Inlay*,
ReVision Optics, Lake Forest, CA, USA).
Methods: 142 presbyopic subjects with near add requirement
(NAR) between 1.50 and +2.50 D with manifest refraction spherical
equivalent (MRSE) between -0.50 D and +1.75 D were implanted
with a 2 mm diameter hydrogel corneal inlay in the non-dominant
eye, under IRB-approved protocols. Uncorrected visual acuity (UVA)
for distance, intermediate and near were tested using the Optec 6500
6 months after surgery. Total-eye wavefront differences were used to
estimate the anterior corneal surface change and these were used as
inputs to a finite eye model for ray-trace analysis. Zemax simulations
of letter charts were used to investigate the contribution of adjacent
annular power zones within the pupil in order to explain the clinical
range of vision.
Results: The average uncorrected distance visual acuity (UDVA)
of treated eyes exceeds 0.2 logMAR over the full preop MRSE
range investigated, reaching 0.1 logMAR above +1 D. Residual
accommodation (2.5 D – Add) does not account for the relatively
high UDVA. Zemax letter chart analysis of the contribution of
8 concentric annular zones within a 5 mm pupil reveals that the
relatively weak slope of the induced axial power profile (-1 D at 3
mm pupil diameter to 0 D @ 4.5 mm diameter) has little effect on
UDVA. For a 4 mm diameter pupil, this distance zone comprises
more than 50% of the pupil area. There is a weak correlation
between UDVA and postop MRSE (r2 = 0.40), which is, as expected,
an approximately linear function of the preop MRSE. Average
intermediate UVA remains approximately 0.1 logMAR across the
whole MRSE range investigated. Zemax simulations suggest a
similar rationale, when applied to the more central pupil zones though
the most peripheral region does reduce contrast. Near vision has been
discussed previously (ARVO 2013).
Conclusions: The smooth gradient power profile centered on the
pupil provides a continuous range of functional vision, minimizing
the power profile’s slope within the pupil, which reduces interference
with image quality from adjacent annular zones in the pupil.
*CAUTION: Investigational device. Limited by Federal (United
States) law to investigational use.
Commercial Relationships: Alan J. Lang, ReVision Optics Inc.
(E); Adam J. Roy, ReVision Optics Inc. (E); Keith Holliday,
ReVision Optics Inc. (E); Tonya Porter, ReVision Optics Inc. (E);
Maggie Young, ReVision Optics Inc. (E)
Program Number: 1547 Poster Board Number: C0186
Presentation Time: 8:30 AM–10:15 AM
Visual Recovery following removal of small aperture intracorneal inlay
Srividhya Vilupuru1, Minoru Tomita2. 1Acufocus, Irvine, CA;
2
Shinagawa LASIK Center, Tokyo, Japan.
Purpose: To evaluate visual recovery and safety after removal of a
small aperture intra-corneal inlay.
Methods: Retrospective analysis of 63 patients who had their inlay
removed at 11.3 ± 7.4 months after implantation. All patients were
monitored for 6 months following inlay removal. Uncorrected and
best-corrected distance and near logMAR visual acuities and manifest
spherical equivalent refraction (MRSE) were measured pre-inlay,
pre-removal and at 1 week, 1 month, 3 months and 6 months postremoval. Data is presented as mean ± SD.
Results: The mean age of patients was 52.6 ± 6.4 years. UDVA was
0.13 logMAR ± 0.26 pre-removal and 0.08 logMAR ± 0.22 at 6
months post-removal (p = 0.37). UNVA was 0.33 ± 0.25 pre-removal
and 0.41 logMAR ± 0.30 at 6 months post-removal (p = 0.21). MRSE
± SD was -0.54D ± 0.27D pre-removal and -0.18D ± 0.78D at 6
months post-removal (p = 0.05). Pre-inlay BDVA was -0.13 logMAR
± 0.07 and at 6 months post-removal BDVA was -0.10 logMAR ±
0.12 (p = 0.13). BDVA recovered to pre-inlay level in 61 out of 63
patients at 6 months post-removal. Six months post-removal, 2 out of
63 patients lost 1 line of pre-inlay BDVA. 100%, 89.3% and 100%
of patients had 0.17 logMAR or better BDVA pre-inlay, pre-removal
and at 6 months post-removal respectively. Both uncorrected & bestcorrected visual acuities recovered by 1 month and stabilized by 3
months post-removal.
Conclusions: Visual recovery following removal of the small
aperture corneal inlay occurs swiftly. Most subjects recover distance
and near visual acuities to pre-inlay level. Small aperture intracorneal inlay implantation remains a safe option for treatment of
presbyopia.
Commercial Relationships: Srividhya Vilupuru, AcuFocus Inc (E);
Minoru Tomita, AcuFocus Inc (C)
Program Number: 1548 Poster Board Number: C0187
Presentation Time: 8:30 AM–10:15 AM
Role of Percentage of Tissue Altered (PTA) as a risk factor in eyes
with Normal preoperative topography that developed Ectasia
after LASIK
Marcony R. Santhiago1, 2, David Smadja4, Beatriz Gomes1, Steven E.
Wilson5, Glauco Mello2, Mario L. Monteiro2, James B. Randleman3.
1
Ophthalmology, Federal University of Rio de Janeiro, Rio de janeiro,
Brazil; 2Refractive Surgery - Ophthalmology, University of Sao
Paulo, Sao Paulo, Brazil; 3Emory Eye Center and Emory Vision,
Atlanta, GA; 4University Hospital of Bordeaux, Bordeaux, France;
5
Cleveland Clinic, Cleveland, OH.
Purpose: The purpose of this study was to investigate in detail the
theoretical role of the percentage of tissue altered (PTA) on ectasia
after LASIK in eyes with normal preoperative topography compared
to risk factors already know.
Methods: This retrospective comparative study included eyes that
developed ectasia with normal preoperative topography. Consecutive
LASIK cases with preoperative normal topography that have not
developed ectasia served as control. Cases were identified after
a detailed analyzes of cases that were referred to the authors’
institution. The PTA is calculated through the sum of flap thickness
(FT) plus the ablation depth (AD) divided by the preoperative
central corneal thickness (CCT). [PTA = (FT + AD)/CCT]. Patient
age, spherical equivalent refraction, CCT, and topographic patterns;
perioperative characteristics, including flap thickness, ablation depth,
residual stromal bed and PTA were investigated.
Results: Thirty eyes met inclusion criteria for this study. PTA was
significantly higher in patients with ectasia and normal topography
compared to controls. Analyzes of the eyes that developed ectasia
with normal topography revealed the PTA as the most prevalent risk
factor (p < 0.0001) and the stepwise logistic regression revealed
the PTA with the higher influence on ectasia and a higher odds ratio
followed by RSB, Age and MRSE. CCT was the risk factor with less
influence
Conclusions: The PTA seems to be a significant risk factor for
ectasia in eyes with pre operative normal topography compared to
controls. The PTA presented a higher influence on ectasia compared
to other risk factors in eyes with normal preoperative topography.
Commercial Relationships: Marcony R. Santhiago, None;
David Smadja, None; Beatriz Gomes, None; Steven E. Wilson,
None; Glauco Mello, None; Mario L. Monteiro, None; James B.
Randleman, None
©2014, Copyright by the Association for Research in Vision and Ophthalmology, Inc., all rights reserved. Go to iovs.org to access the version of record. For permission
to reproduce any abstract, contact the ARVO Office at [email protected].
ARVO 2014 Annual Meeting Abstracts
Program Number: 1549 Poster Board Number: C0188
Presentation Time: 8:30 AM–10:15 AM
Long-term Outcomes of Post-Penetrating Keratoplasty
Astigmatic Keratotomy Performed Using 30kHz Femtosecond
Laser Flap Mode Software vs 150kHz Femtosecond Laser
Enabled Astigmatic Keratotomy Software
Priyanka Chhadva1, 2, Florence Cabot2, 3, Vardhaman Kankariya1, 2,
Sonia H. Yoo2, 3. 1University of Miami Miller School of Medicine,
Miami, FL; 2Ophthalmology, Anne Bates Leach Eye Hospital,
Bascom Palmer Eye Institute, University of Miami Miller School
of Medicine, Miami, FL; 3Ophthalmology, Ophthalmic Biophysics
Center, Bascom Palmer Eye Institute, Miami, FL.
Purpose: This study assesses the long-term outcomes of astigmatic
keratotomy (AK) performed with two different techniques in patients
with post-penetrating keratoplasty (post-PK) residual astigmatism.
Methods: This retrospective study included 11 eyes of 11 patients
who underwent post-PK AK performed using either 30kHz
femtosecond laser flap mode software (IntraLase/AMO, Irvine, CA)
-Group 1- or using 150kHz femtosecond laser enabled AK software
(IntraLase/AMO, Irvine, CA) -Group 2- to create two anterior arcuate
corneal incisions. Preoperative and postoperative follow-up data,
including uncorrected visual acuity (UCVA), best corrected visual
acuity (BCVA), spherical equivalence (SE), average keratometry
(avgK), and corneal cylinder (CC) were recorded and analyzed to
determine visual outcomes and long-term results of these procedures.
The student t-test was used to compare the two groups, and p<0.05
was considered statistically significant.
Results: No complications were seen using either technique. In
Group 1 (n=5), the preoperative mean UCVA was 0.99LogMAR,
mean BCVA was 0.48LogMAR, mean SE was -0.89 diopters
(D), mean avgK was 45.45D, and mean CC was 10.82D. The
postoperative mean UCVA was 0.48LogMAR, mean BCVA was
0.27LogMAR, mean SE was -1.53D, mean avgK was 46.67D, and
mean CC was 5.48D. In Group 2 (n=6), the preoperative mean
UCVA was 1.03LogMAR, mean BCVA was 0.52LogMAR, mean
SE was -0.08D, mean avgK was 45.38D, and mean CC was 9.35D.
The postoperative mean UCVA was 0.77LogMAR, mean BCVA was
0.15LogMAR, mean SE was -3.18D, mean avgK was 57.43D, and
mean CC was 3.24D. In Group 1, the difference between preoperative
and postoperative BCVA was not statistically significant (p=0.63). In
Group 2, postoperative BCVA showed clinical improvement, even
though the difference between preoperative and postoperative BCVA
was not statistically significant (p=0.06).
Conclusions: AK performed with both techniques are safe and
efficient procedures to correct post-PK residual astigmatism.
Commercial Relationships: Priyanka Chhadva, None; Florence
Cabot, None; Vardhaman Kankariya, None; Sonia H. Yoo, AMO
(F)
Program Number: 1550 Poster Board Number: C0189
Presentation Time: 8:30 AM–10:15 AM
Biomechanical Stiffness Changes of Collagen Crosslinking
on Human Keratoconic Corneas using Scanning Acoustic
Microscopy
Ithar M. Beshtawi1, Riaz Akhtar2, Chantal Hillarby3, Clare O3,
Xuegen Zhao3, Arun Brahma4, Fiona Carley4, Brian Derby3, Hema
Radhakrishnan3. 1An-Najah National University, Nablus, Palestine,
State of; 2University of Liverpool,, Liverpool, United Kingdom; 3The
University of Manchester, Manchester, United Kingdom; 4Manchester
Royal Eye Hospital, Manchester, United Kingdom.
Purpose: To assess the biomechanical stiffness of collagen crosslinking on keratoconic corneas, in-vitro
Methods: Six keratoconic corneal buttons were included in this
study. Each cornea was divided into two halves, where one half was
cross-linked and the other half was treated with riboflavin only and
served as control. The stiffness of the corneal tissue was measured
across the stroma using scanning acoustic microscopy (SAM).
Results: In the cross-linked corneas, there was a steady decrease in
the magnitude of speed of sound from the anterior region through to
the posterior regions of the stroma. The speed of sound was found to
remain relatively unchanged in the control corneas. The increase in
stiffness between the cross-linked and control corneas in the anterior
200 × 200 μm region was by a factor of 1.039x.
Conclusions: A higher speed of sound was detected in cross-linked
keratoconic corneal tissue when compared with their controls, using
SAM. This in vitro model can be used to compare to the cross-linking
results obtained in-vivo, as well as comparing the results obtained
with different protocols.
Commercial Relationships: Ithar M. Beshtawi, None; Riaz
Akhtar, None; Chantal Hillarby, None; Clare O, None; Xuegen
Zhao, None; Arun Brahma, None; Fiona Carley, None; Brian
Derby, None; Hema Radhakrishnan, None
©2014, Copyright by the Association for Research in Vision and Ophthalmology, Inc., all rights reserved. Go to iovs.org to access the version of record. For permission
to reproduce any abstract, contact the ARVO Office at [email protected].
ARVO 2014 Annual Meeting Abstracts
Program Number: 1551 Poster Board Number: C0190
Presentation Time: 8:30 AM–10:15 AM
Quantification of corneal density changes following corneal
collagen crosslinking and its relationship to clinical outcomes
Brad E. Kligman1, Leejee H. Suh1, Francis W. Price2, Marianne O.
Price3, Stephen L. Trokel1. 1Ophthalmology, Edward S. Harkness Eye
Institute, Columbia University Medical Center, New York, NY; 2Price
Vision Group, Indianapolis, NY; 3Cornea Research Foundation of
America, Indianapolis, IN.
Purpose: To identify the relationship between the presence and
extent of corneal haze measured with Pentacam densitometry
software, corneal thickness, and visual outcomes following corneal
collagen crosslinking (CXL).
Methods: Corneal indices in 26 eyes of 26 patients who underwent
CXL in two independent centers were measured using the Pentacam
device (Oculus, Germany). Measurements were taken preoperatively
and at 1, 3, 6 and 12 months after CXL. Retrospective analysis was
performed using the Pentacam software to determine the corneal
density (measured as percentage of light scattered), corneal thickness,
astigmatism, and maximum keratometry. Visual function outcomes
were measured at these time points and included best corrected visual
acuity (BCVA) and manifest refraction (spherical equivalent).
Results: Corneal density increased immediately following CXL, then
decreased between 1 and 6 months postoperatively. Between 6 and 12
months, the density continued to decrease but less dramatically. The
majority of the increase in corneal density occurred in the anterior
120mm of the cornea, representing the location of the previously
described “stromal demarcation line.” Changes in corneal density had
an inverse relationship with corneal thickness. Astigmatism, BCVA
and spherical equivalent (myopia) worsened during the initial spike
in corneal density, then gradually improved and stabilized from 3 to
12 months as the corneal density decreased and stabilized. Patients
with a more extensive change in corneal density from baseline tended
to have a greater improvement in topographical astigmatism and
BCVA at 1 year.
Conclusions: The densitometry software in the Oculus Pentacam
is a novel way to detect and quantify the increase in corneal density
following CXL. There is an acute phase within 1 month following
CXL with increased density with a corresponding thinning of the
cornea, possibly representing an inflammatory or healing phase.
During this time, there is an acute decline in visual function measures
due to corneal haze, which should be anticipated by the operating
physician and patient. This is followed by a decrease in the corneal
density as well as improvement and stabilization of visual function
at 1 year following the treatment. In our series, there was a positive
correlation between the extent of maximum change in corneal density
and improvement in some clinical parameters.
Commercial Relationships: Brad E. Kligman, None; Leejee H.
Suh, None; Francis W. Price, Oculus (R); Marianne O. Price,
None; Stephen L. Trokel, None
Program Number: 1552 Poster Board Number: C0191
Presentation Time: 8:30 AM–10:15 AM
Photochemical Intra-Stromal Cross-linking for Presbyopia and
Hyperopia
Satish Herekar1, Marc D. Friedman1, David Muller1, Harald P.
Studer3, Anastasios J. Kanellopoulos2. 1Avedro, Waltham, MA;
2
LaserVision, Athens, Greece; 3Integrated Scientific Services, 2562
Port, Switzerland.
Purpose: To determine the effects of using patterned UVA light
during photo-chemical cross-linking as a means of inducing corneal
multi-focality for Hyperopic and Presbyopic corrections.
Methods: Patient specific FEA modeling (Optimeyes, ISS, CH,
using full 3D model of cornea, limbus and scleral ring of 4mm width
~50’000 first order brick elements per model, 5 layers of elements
over thickness, IOP=15mmHg, with pre-stressing assuming bulk
cross-linking over an annulus 5.0mm to 8.5mm diameter and 250ums
depth and 400ums depth at 2.5 times stiffening) was undertaken to
predict curvature and wavefront change results.
Fresh whole porcine eyes were obtained <24 hours postmortem in
saline on ice from Sioux-preme (Sioux City, IA). Eyes were brought
to 37oC in a humidity chamber, epithelium was removed with a dull
blade, and intraocular pressure of 15mmHg was applied using a water
column. 0.1% Rf in 0.85% saline drops were applied in the humidity
chamber for 20 minutes. Eyes were scanned (Pentacam HR) then
placed under a programmable UVA pattern projector (KXL II) and
irradiated at 30mW/cm2 while pulsing 1 sec ON and 1 sec OFF with
dual annuli (2mm-4mm and 5.5mm to 7.5mm) for a total UVA dose
of 22 minutes (20J/cm2). The eyes were then scanned (Pentacam HR)
once again to obtain curvature, densitometry, and wavefront changes.
Two hyperopic patients (Athens Gr) were treated (by AJK, deepithelialized and 0.1% riboflavin soaked first) with 7.2J/cm2 and
12J/cm2 30mW/cm2 patterned with single annulus 6mm to 9mm, 1
sec ON, 1 sec OFF and topography pre and post scans were obtained.
Results: FEA curvature and wavefront analysis showed an increase
in central corneal curvature and spherical aberration. Topographies/
densitometries of pig eyes showed para-central steepening and
peripheral flattening. Both patients showed central steepening.
Conclusions: FEA, ex-vivo pig eyes and patient outcomes indicated
induction of corneal multi-focal changes in a dose dependent manner
towards correction of hyperopia and presbyopia due to photochemical intra-stromal cross-linking.
Commercial Relationships: Satish Herekar, Avedro Inc. (E); Marc
D. Friedman, Avedro Inc. (E); David Muller, Avedro Inc. (E);
Harald P. Studer, Avedro Inc. (C); Anastasios J. Kanellopoulos, a
(C)
Program Number: 1553 Poster Board Number: C0192
Presentation Time: 8:30 AM–10:15 AM
Effect of Novel Architecture for Femtosecond Laser Astigmatic
Keratotomy on Induced Aberration on Patient-Specific
Computational Modeling
Anita Nevyas-Wallace1, Harald P. Studer4, Cynthia J. Roberts2, 3.
1
Nevyas Eye Associates, Bala Cynwyd, PA; 2Ophthalmology, The
Ohio State University, Columbus, OH; 3Biomedical Engineering, The
Ohio State University, Columbus, OH; 4Integrated Scientific Services,
Port, Switzerland.
Purpose: To compare novel astigmatic keratotomy (AK) incision
architectures to standard AK using patient-specific computational
modeling to evaluate astigmatic effect and induction of higher order
aberrations (HOA)
Methods: Finite element modeling (Optimeyes) was used to perform
simulations of femtosecond (FS) laser arcuate corneal relaxing
incisions on patient-specific corneal models. Modeling (previously
validated clinically) accounted for corneal stroma being denser
anteriorly than posteriorly. Simulations of AK incisions of uniform
depth and thickness were compared with those of AK incisions whose
ends were either deeper, thicker, or both deeper and thicker than the
center of the incision. Astigmatic effect and induced higher order
aberration were assessed for incisions 30 degrees in length made at
the 8mm optical zone.
Results: Compared with incisions of uniform depth and thickness,
shallow center incisions achieved 13% greater astigmatic effect,
and diminished induced HOA: spherical aberration by 26%, coma
by 21%, trefoil by 100%, and tetrafoil by 3%. Uniform depth
©2014, Copyright by the Association for Research in Vision and Ophthalmology, Inc., all rights reserved. Go to iovs.org to access the version of record. For permission
to reproduce any abstract, contact the ARVO Office at [email protected].
ARVO 2014 Annual Meeting Abstracts
incisions with thicker ends achieved 1% greater astigmatic effect,
and diminished induced spherical aberration by 18%, coma by 74%,
trefoil by 99%, and increased tetrafoil by 17%. The thicker ends with
shallower center incisions achieved 15% greater astigmatic effect,
and diminished induced HOA: spherical aberration by 20%, coma by
82%, trefoil by 81%, and tetrafoil by 20%.
Conclusions: Novel FS laser AK incisions with thicker ends and
shallower center produced optimal results with greatest astigmatic
effect and least induction of HOA. All novel architectures generated
greater astigmatic effect and less induced HOA than traditional.
Control of incision architecture may aid in optimizing vision in FS
laser AK.
All combinations of Thicker Ends Shallow Center show Reduced
Coma compared to traditional corneal relaxing incision
Some combinations of Thicker Ends Shallow Center show Greater
Astigmatic Correction compared to traditional incision, even though
they induce less HOA
Commercial Relationships: Anita Nevyas-Wallace, Bausch +
Lomb (C), EyeIC (I), Patent application number 13/402,389 (P),
Varitronics, Inc. (I); Harald P. Studer, ISS Integrated Scientific
Services AG (E); Cynthia J. Roberts, Carl Zeiss Meditec: (F),
Oculus (C), Sooft Italia: (R), Ziemer (C)
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Program Number: 1554 Poster Board Number: C0193
Presentation Time: 8:30 AM–10:15 AM
Post keratoplasty astigmatism in a 5 years period
Karla Alejandra Ramirez Collazo, Oscar Baca, Regina Velasco,
Alejandro Babayan, Cristina Pacheco Del Valle, Elisa D. Alegria,
Oscar Fernandez. Cornea, Hospital de la Luz, Mexico, Mexico.
Purpose: To determine the amount of astigmatism after penetrating
keratoplasty in a 5 year period at the Fundación Hospital Nuestra
Señora de la Luz, IAP.
Methods: This is a retrospective cross-sectorial study. Patients
with penetrating keratoplasty (PK) in a period of five years at the
Fundación Hospital Nuestra Señora de la Luz, IAP were included.
The amount of astigmatism, sphere, spherical equivalent (SE), visual
acuity (logMar) and best corrected visual acuity (BCVA), before
and after PK were reviewed. We classified patients into four groups:
Group1: Patients with hyperopia, group 2 patients with mild myopia
( < - 3.00 D ), group 3 patients with moderate myopia ( -3.00 D to 6.00) and group 4 patients with high myopia (greater than > -6.00 D).
Suture removal began at month 6 in all patients. Protocol of removal
with topography was done.
Results: Four hundred and twelve files were reviewed, 35 eyes, of
patients had a complete record (8.49%). In group 1 the preoperative
(SE) average was + 4.07 D ± 1.70 (n=7) and + 2.02 D ± 1.45 (n=5)
in the postoperative period, group 2: - 2.62 D ± 0.53 (n=2) and - 1.85
D ± 0.95 (n=7), group 3: -4.75 D ± 1.21 (n = 6) and -4.53 D ± 0.69
(n = 17), Group 4: -13.16 D ± 5.09 (n = 20) and -9.30 D ± 1.95 (n =
7), respectively. Patients after one year of surgery were cataloged.
In group 1 were included 20% in the preoperative and 14.28% in the
postoperative, in group 2 were 5.71% preoperative and 17.14 % in
the postoperative, in group 3 were 17.14% preoperative and 48.57%
in the postoperative and group 4 were 35% preoperative and 20%
in the postoperative. The presence of preoperative astigmatism was
in average – 5.47 D ± 2.63 and - 4 .07 D ± 2.05 postoperative. The
coefficient of variation was 0.426, for each diopter of astigmatism
after surgery, preoperative modified in 0.426 this value with a
confidence interval (CI) of 0.195-0.658, (p = 0.001).
Conclusions: The predominant reduction of astigmatism was found
in group 3 with 48.57%. After one year of keratoplasty 85% of
patients switched their refraction. Our post keratoplasty astigmatism
average is comparable with other in training school hospitals.
Commercial Relationships: Karla Alejandra Ramirez Collazo,
None; Oscar Baca, None; Regina Velasco, None; Alejandro
Babayan, None; Cristina Pacheco Del Valle, None; Elisa D.
Alegria, None; Oscar Fernandez, None
Program Number: 1555 Poster Board Number: C0194
Presentation Time: 8:30 AM–10:15 AM
Femtosecond Laser-Assisted Astigmatic Keratotomy for
Astigmatic Correction in Pseudophakic Eyes
Yosai Mori1, Ryohei Nejima1, Yukiko Terada2, Yumi Hasegawa1,
Nobuyuki Nagai1, Miyuki Ogata1, Keiichiro Minami1, Kazunori
Miyata1. 1Miyata Eye Hospital, Miyakonojo, Japan; 2Tokyo Medical
and Dental University, Tokyo, Japan.
Purpose: Astigmatic keratotomy (AK) effectively reduce corneal
astigmatism without the need for expensive equipment. The
predictability is lower than astigmatic correction using excimer
laser. Femtosecond laser-assisted AK (FSL-AK) has been used for
correcting high astigmatism after penetrating keratoplasty, and its
accurate resections and acceptable astigmatism reductions have been
reported. However, there was no assessment in use for eye after
cataract surgery. This prospective study was to assess the efficacy of
FSL-AK for astigmatic correction in pseudophakic eyes.
©2014, Copyright by the Association for Research in Vision and Ophthalmology, Inc., all rights reserved. Go to iovs.org to access the version of record. For permission
to reproduce any abstract, contact the ARVO Office at [email protected].
ARVO 2014 Annual Meeting Abstracts
Methods: Eight eyes of six patients who received an intraocular lens
and corneal astigmatism of 2.0 diopters (D) or more underwent FSLAK. Mean preoperative uncorrected distance visual acuity (UDVA)
was 0.52 ± 0.21 logMAR, and the manifest cylindrical refraction
(CYL) and corneal astigmatism were 2.88 ± 0.64 D and 2.84 ± 0.83
D, respectively. AK incisions were created using the IntraLase iFS
laser (Abbott Medical Optics). Paired symmetrical arcuate incisions
with a diameter of 8.5 mm and length of 80 degrees were created with
a depth of 350 or 375 mm. Outcome measures included UDVA, CYL,
and surgically induced astigmatism (SIA) at 1 week and 1 month
postoperatively. Corneal topography (TMS-4 Advance, Tomey) was
compared between preoperatively and 1 month postoperatively using
Fourier analysis. The incisional depth was measured using anteriorsegment optical coherence tomography (SS-1000, Tomey) at 1 month
postoperatively. The differences between the measured and intended
incisional depths were compared.
Results: UDVA improved significantly to 0.33 ± 0.13 logMAR,
0.21 ± 0.17 logMAR at 1 week and 1 month (P=0.013 and P=0.01,
respectively). CYL decreased significantly to 0.97 ± 0.77 D, 0.91
± 0.64 D at 1 week and 1 month, respectively (P<0.027). SIA at 1
month was 3.22 ± 1.37 D. Fourier analysis at 6 mm diameter zone
showed significant decreases in spherical and regular astigmatic
components (P<0.05) and significant increases in high-order irregular
astigmatism (P=0.05). The mean incision depth was 416.3 ± 38.9 mm,
which was 60 mm deeper than the intended depth.
Conclusions: FSL-AK reduced astigmatism in pseudophakic eyes
and improved the UDVA, while the SIA and measured incision
depth demonstrated a trend of overcorrection. Development of a new
nomogram is required to increase the accuracy.
Commercial Relationships: Yosai Mori, None; Ryohei Nejima,
None; Yukiko Terada, None; Yumi Hasegawa, None; Nobuyuki
Nagai, None; Miyuki Ogata, None; Keiichiro Minami, None;
Kazunori Miyata, None
Program Number: 1556 Poster Board Number: C0195
Presentation Time: 8:30 AM–10:15 AM
Impact of corneal thickness and posterior corneal curvature on
total corneal astigmatism
Bastian Tonn, Thomas Kohnen, Oliver Klaproth. Ophthalmology,
Goethe-University Frankfurt am Main, Frankfurt am Main, Germany.
Purpose: Description of total corneal refractive power (TCRP)
astigmatism evaluated by ray-tracing using a rotating Scheimpflug
camera (Pentacam HR, Oculus).
Methods: Retrospective analysis of Scheimpflug camera
measurements to determine 4mm-zone TCRP astigmatism by ray
tracing, corneal astigmatism from simulated keratometry (Sim-K,
15°-zone), anterior corneal astigmatism (ACA), corneal thickness
(CT) and posterior corneal astigmatism (PCA). An analysis of
changes with age was performed. The error produced by estimating
TCRP astigmatism by using Sim-K was calculated through vector
analyses.
Results: 3818 eyes of 2233 subjects were analyzed. The mean
magnitude of PCA was -0.33 diopter (D). A vertically aligned steep
corneal meridian (60 to 120 degrees) was found in 71.2% of eyes for
ACA and in 88.8% for PCA. With increasing age, the occurrence of
steep ACA meridian aligned horizontally increased from 9.1% (age
20-29yrs) to 31.8% (70-79yrs), while vertical alignment decreased
from 77.4% to 48.1% and the steep PCA meridian mostly remained
vertically (90.9% to 80.7%). A positive correlation between the
magnitudes of ACA and PCA could be shown. The mean vector
difference between TCRP and Sim-K was 0.21 at 96° and exceeded
0.50 D in 2% of eyes.
Conclusions: TCRP astigmatism cannot be predicted safely by
anterior corneal measurements only. Neglecting posterior corneal
astigmatism may conclude in visual significant overcorrection
or undercorrection in some cases when e.g. toric intraocular lens
implantation is performed.
Differences between anterior corneal steep meridian and posterior
corneal steep meridian as a function of the differences in magnitude
between TCRP and Sim-K.
Magnitude of astigmatism on the anterior corneal surface and
posterior corneal surface with steep meridian aligned vertically on the
anterior cornea.
Commercial Relationships: Bastian Tonn, None; Thomas
Kohnen, Abbott (C), Abbott (R), Alcon (C), Alcon (R), B+L (C),
B+L (R), Hoya (C), Hoya (R), Neoptics (C), Neoptics (R), Oculus
(C), Oculus (R), Rayner (C), Rayner (R), Schwind (C), Schwind (R),
Thieme (C), Thieme (R), Zeiss (C), Zeiss (R); Oliver Klaproth,
Alcon (R), Oculus (R), Rayner (R)
Program Number: 1557 Poster Board Number: C0196
Presentation Time: 8:30 AM–10:15 AM
Comparative study of the outcome of LASIK in Moderate versus
High Astigmatism
Guillermo Mendoza, Juan Francisco Lozano, Alejandro Tamez, Jesus
Lozano, Judith Zavala, Jorge E. Valdez. Ophthalmology Research
Chair, Tecnologico de Monterrey, Monterrey, Mexico.
Purpose: To compare the outcomes of treatment with LASIK in
eyes cataloged as moderate astigmatism versus those with high
astigmatism.
Methods: Retrospective study. A random sample from the service
of Cornea and Refractive surgery of 56 patients were analyzed. The
data collected was sphere, cylinder, spherical equivalent, uncorrected
visual acuity (UCVA), and best corrected visual acuity (BCVA).
Astigmatism was defined as moderate for eyes with a cylinder ≥ 1.5
and ≤2.75 D, while high astigmatism was ≥3.00 D. Snellen visual
acuity was converted to LogMAR for statistical analysis.
©2014, Copyright by the Association for Research in Vision and Ophthalmology, Inc., all rights reserved. Go to iovs.org to access the version of record. For permission
to reproduce any abstract, contact the ARVO Office at [email protected].
ARVO 2014 Annual Meeting Abstracts
Results: A total of 82 eyes of 56 patients were analyzed with 41 eyes
categorized as moderate astigmatism and 41 as high astigmatism. The
mean age of the sample was 28.5 years. Mean follow up 2.96 months
(1-6 months). The mean preoperative cylinder was -2.1 and -4.2
for moderate and high astigmatism respectively. Mean preoperative
spherical equivalent for moderate astigmatism was -3.4, and -2.1 for
high astigmatism; this was reduced postoperatively to 0.08 and -0.55
respectively.
Most patients in the high astigmatism group were compound myopic
(41.5 %) and mixed (39 %), while most moderate astigmatism were
compound hyperopic (73 %) (Table 1).
Thirty and 28 eyes achieved UCVA ≥20/20, 11 and 12 eyes reached
UCVA ≤20/ 25 and ≥20 /40 in the high and moderate astigmatism
groups respectively (Table 2).
In 7 and in 3 eyes of the high and moderate astigmatism groups
respectively a line of BCVA was improved, while in either group was
lost.
No statistical difference was observed between the groups of
moderate and high astigmatism for the BCVA (p=0.121) and UCVA
(p=0.469) variables. No postoperative complications were observed
in either group.
Conclusions: Treatment with LASIK in patients with high
astigmatism and moderate astigmatism showed no difference in the
postoperative results after a follow-up period of 1 to 6 months.
Results: A nine-eye series was retrospectively studied. The
preoperative cylinder was 6.11 D ± 2.54. The mean postoperative
astigmatism was 2.22 D ± 0.91. Mean correction index was 1.07 D
± 0.28. Mean best corrected visual acuity improved from 20/45 to
20/22. Mean follow-up was 5.2 months ± 3.2. No complication was
observed and postoperative outcome is satisfactory.
Conclusions: In addition to higher range and good accuracy, this
innovative method prevents postoperative complications as incisions
respects the corneal surface, and spares corneal stroma for the
correction of high astigmatism.
Commercial Relationships: Laurent Laroche, None; Patrick
Loriaut, None; Otman Sandali, None; Isabelle Goemaere, None;
Nacim Bouheraoua, None; Cyril Temstet, None; Elena Basli,
None; Vincent Borderie, None
Distribution of eyes by type of astigmatism.
Table 2. Visual Acuity at the end of the follow up period.
Commercial Relationships: Guillermo Mendoza, None; Juan
Francisco Lozano, None; Alejandro Tamez, None; Jesus Lozano,
None; Judith Zavala, None; Jorge E. Valdez, None
Program Number: 1558 Poster Board Number: C0197
Presentation Time: 8:30 AM–10:15 AM
A new combined technique of Deep Intrastromal Arcuate
Keratotomy (DIAK) overlayed by LASIK flap for the treatment
of high astigmatism
Laurent Laroche1, 2, Patrick Loriaut1, Otman Sandali1, Isabelle
Goemaere1, Nacim Bouheraoua1, 2, Cyril Temstet1, Elena Basli1,
Vincent Borderie1, 2. 1CHNO des Quinze-Vingts, Paris, France;
2
UPMC, Paris, France.
Purpose: To describe a new technique combining Deep Intrastromal
Arcuate Keratotomies (DIAK) and Superficial Lamellar Keratotomy
(SLK) followed by excimer photoablation for management of high
naturally occurring or post-keratoplasty astigmatisms.
Methods: The first procedure was performed by femtosecond laser
and included DIAK and SLK, which were scheduled at 100 mm.
The flap was lifted and the incisions were manually opened. One
month later, the flap was relifted and an Excimer laser treatment was
performed to correct the residual ametropia.
©2014, Copyright by the Association for Research in Vision and Ophthalmology, Inc., all rights reserved. Go to iovs.org to access the version of record. For permission
to reproduce any abstract, contact the ARVO Office at [email protected].