Download Prospective Clinical Trial of Mediflex Posterior Chamber Acrylic

Prospective Clinical Trial of Mediflex Posterior Chamber Acrylic
Intraocular Lens: 1-Year Results.
Marcelo M. F. Lemos MD.
NOBHE: Núcleo de Oftalmologia de Belo Horizonte
Belo Horizonte – Brazil.
August 2009
Prospective Clinical Trial of Mediflex Posterior Chamber Acrylic Intraocular Lens: 1-Year Results.
Table of Contents:
Page
Study Objectives:
3
Study Design:
4
Clinical Inclusion and Exclusion Criteria:
5
Follow-up Schedule:
7
Accountability of study Cohort:
8
Demographics:
9
Safety and Effectiveness Results
10
Discussion of Results:
12
Page 2 of
2
Prospective Clinical Trial of Mediflex Posterior Chamber Acrylic Intraocular Lens: 1-Year Results.
Study Objectives:
The present study has been conducted to establish a reasonable assurance of safety and
effectiveness of intraocular implantation with the Mediflex posterior chamber foldable acrylic
intraocular lens (Mediphacos Ltda. Belo Horizonte, Brazil) for visual correction of aphakia in
adult patients where a cataractous lens has been removed by phacoemulsification. The Mediflex
is a one-piece hydrophobic acrylic posterior chamber intraocular lens with a 6mm aspheric
optic and 13mm overall length modified “C” haptics.
Page 3 of
3
Prospective Clinical Trial of Mediflex Posterior Chamber Acrylic Intraocular Lens: 1-Year Results.
Study Design:
Patients were treated between November 12, 2007 and July 7, 2008. The results herein
presented reflect data collected through June 30, 2009. 35 (thirty five) patients were enrolled
for the study. The Mediflex lens was evaluated in a 12-month, prospective, single-center clinical
investigation to establish safety and effectiveness compared to historical literature controls,
specifically the FDA "Grid" of cataract surgery results. In the past, the data reported in Stark, W.
J., et al., The FDA Report on Intraocular Lenses, Ophthalmology, 90(4):311-317, 1983 has been
used as an historical control. This data has been updated from recent approved IOL experience
for adverse reaction rates, sight-threatening complication rates and visual acuity results, for
comparison to new lens models.
Page 4 of
4
Prospective Clinical Trial of Mediflex Posterior Chamber Acrylic Intraocular Lens: 1-Year Results.
Clinical Inclusion and Exclusion Criteria:
Enrollment in the present study was limited to patients who met the following inclusion
criteria:
*Patients had a clinically documented diagnosis of age-related cataract (cortical, nuclear,
subcapsular, or a combination) that was considered amenable to treatment with
standard phacoemulsification extracapsular cataract extraction.
*Patients were adults18 years of age or older.
*Patients were eligible to undergo primary intraocular lens implantation for the
correction of aphakia following continuous curvilinear anterior capsulotomy and
phacoemulsification cataract extraction.
* Patients were willing and able to return for scheduled follow-up examinations for one
year following surgery.
*Patients required intraocular lens powers ranging from 15 to 30 diopters.
*Patients had a visual potential of 20/40 or better in the study eye.
Patients were not permitted to enroll in the Mediflex posterior chamber IOL
study if they met any of the following exclusion criteria:
* Patients who had best-corrected distance visual acuity of 20/200 or less in the fellow
eye.
* Patients with any anterior segment pathology for which extracapsular
phacoemulsification cataract surgery would be contraindicated (e.g., chronic uveitis,
iritis, iridocyclitis, rubeosis iridis, clinically significant corneal dystrophy, clinically
significant Fuchs' dystrophy, clinically significant anterior membrane dystrophy, etc.).
* Any inflammation or edema (swelling) of the cornea, including but not limited to the
following: keratitis, keratoconjunctivitis, and keratouveitis.
* Patients with uncontrolled glaucoma or glaucoma under current treatment in the eye
to be implanted.
*Patients with previous retinal detachment.
*Patients with diabetic retinopathy (proliferative or non-proliferative).
*Patients with rubella, bilateral congenital, traumatic, or complicated
cataract.
*Patients with marked microphthalmos or aniridia.
Page 5 of
5
Prospective Clinical Trial of Mediflex Posterior Chamber Acrylic Intraocular Lens: 1-Year Results.
*Patients who have had previous ocular surgery in the planned operative eye.
*Patients who have already received a Mediflex lens in the fellow eye.
* Irregular corneal astigmatism.
* Amblyopia.
* Clinically significant retinal pigment epithelium/Macular changes.
* Iris neovascularization.
* Recurrent severe anterior or posterior segment inflammation due to unknown
etiology.
* Optic atrophy.
* Patients with immunodeficiency conditions.
* Patients with chronic use of systemic steroids or immunosuppressive medications.
* Patients concurrently participating in another clinical trial.
Page 6 of
6
Prospective Clinical Trial of Mediflex Posterior Chamber Acrylic Intraocular Lens: 1-Year Results.
Follow-up Schedule:
All patients were scheduled to return for follow-up examinations at 1-2 days, 7-14 days,
30-60 days, 120-180 days, and 330 -420 days postoperatively. Preoperatively, patients
scheduled to undergo cataract extraction and intraocular lens implantations were
screened for eligibility, and eligible patients were evaluated to obtain a medical history
and to establish a baseline for ocular condition.
Patients underwent small incision surgery, continuous curvilinear anterior capsulorhexis,
extracapsular cataract extraction via phacoemulsification, and in-the-bag implantation of
the Mediflex intraocular lens. For each patient, only one eye had an IOL implanted as
part of this investigation.
Postoperatively, patients underwent a complete ophthalmic evaluation at regularly
scheduled intervals to assess the condition of their eyes and visual function for 12
months after their cataract surgery. Adverse events and complications were recorded
at all visits.
Page 7 of
7
Prospective Clinical Trial of Mediflex Posterior Chamber Acrylic Intraocular Lens: 1-Year Results.
Accountability of study Cohort:
At the time of database lock, of the 35 patients enrolled in the study, 91% (32) subjects
were available for analysis at the completion of the study, the 12 month postoperative
visit. 3 subjects were lost to follow up, all of which deceased before completion of the
last postoperative visit due to natural causes.
Page 8 of
8
Prospective Clinical Trial of Mediflex Posterior Chamber Acrylic Intraocular Lens: 1-Year Results.
Demographics:
The demographics of the study population are typical for several other IOL studies. The
population at risk for developing visually disabling cataracts and needing cataract surgery
is typically the elderly; the elderly population has a slightly higher proportion of females
to males.
Table 1 – Gender Distribution
Gender
Male
Female
Grand Total
% Distribution
40%
60%
100,00%
Number of Eyes
14
21
50
Table 2 – Age Group Distribution
Age Group
1. < 60 years
2. 60 - 69 years
3. 70 - 79 years
4. > 80 years
Grand Total
% Distribution
Eyes
8.5%
3
40%
14
42.8%
15
8.5%
3
100,00%
50
Page 9 of
9
Prospective Clinical Trial of Mediflex Posterior Chamber Acrylic Intraocular Lens: 1-Year Results.
Safety and Effectiveness Results
Safety Results
The analysis of safety was based on adverse event rates compared to historical controls,
specifically the FDA "Grid" of cataract surgery results. In the past, the data reported in
Stark, W. J., et al., The FDA Report on Intraocular Lenses, Ophthalmology, 90(4):311317, 1983 has been used as an historical control.
These data have been updated from recent approved 1OL experience for adverse
reaction rates, sight-threatening complication rates and visual acuity results, for
comparison to new lens models. The key safety outcomes, cumulative and persistent
adverse events, for this study are presented below
Adverse effects that occurred in the clinical study:
Table 3: Cumulative Adverse Events (Occurring at any time during the study):
Cumulative Adverse
Event
Hyphema
Macular Edema
Retinal Detachment
Pupillary Block
Lens Dislocation
Endophthalmitis
Hypopyon
Surgical Reintervention
% Mediflex Incidence
N = 35
FDA Grid %
0
2.2
2.8
3
0
3
0
0.1
0
0.1
0
0.1
0
0.3
0
0.8
Table 4: Persistent Adverse Events (Present at the 1-year postoperative
examination
Persistent Adverse Event
Macular Edema
Corneal Edema
Iritis
Raised IOP Requiring
Treatment
% Mediflex Incidence
N = 35
2.8*
FDA Grid %
0.5
0
0.3
0
0.3
2.8
0.1
*One patient (2.8%) was counted for both cumulative and persistent macular forms.
Page 10 of
10
Prospective Clinical Trial of Mediflex Posterior Chamber Acrylic Intraocular Lens: 1-Year Results.
Effectiveness Results:
The analysis of effectiveness was based on visual acuity at the twelve-month time point.
Key effectiveness outcomes are presented in tables 5 and 6. The rate for overall 20/40
or better visual acuity for the cohort population exceed the FDA grid values.
Table 5 – BSCVA by Age Group (Month 12)
Age Group
1. < 60 years
2. 60 - 69 years
3. 70 - 79 years
4. > 80 years
Grand Total
20/40
Eyes
3
14
14*
0**
31
FDA Grid
% Distribution
N=32
100%
100%
93.3%
0%
96.8%
97,90%
95,70%
93,40%
86,50%
92,50%
* Of the 32 patients that reached the 1-year postoperative visit, 1 patient did not
achieve BSCVA 20/40.
** All 3 patients originally enrolled in the > 80 years age group were lost to follow up
and did not reach the 1-year postoperative visit.
Page 11 of
11
Prospective Clinical Trial of Mediflex Posterior Chamber Acrylic Intraocular Lens: 1-Year Results.
Discussion of Results:
We note that although the study sample size is small (N=35) in comparison to clinical
studies that yielded FDA grid results, the Mediflex intraocular lens presented very
satisfactory visual outcomes, exceeding FDA grid results for BSCVA in all age groups,
except age group 4 (> 80 yrs.). It was not possible to assess BSCVA results for group 4
since all subjects were lost to follow up at the 1-year postoperative visit. BSCVA for
pooled subjects was 20/40 or better in 96.8% of eyes, thus exceeding FDA grid for
posterior chamber IOLs (92.50%).
The Mediflex cumulative and persistent adverse event rates at 12 months are lower
than the FDA historical control grids in all areas except macular edema and raised IOP
requiring treatment, but these rates are not statistically significantly different from the
FDA grid rates given the small sample size of the study. Only 1 patient presented
persistent macular edema and 1 patient presented raised IOP requiring treatment. It
was not possible to correlate these complications to the study intraocular lens.
The data in this study support the reasonable assurance of safety and effectiveness of
this device when used in accordance with the indications for use: primary implantation
for the visual correction of aphakia in adults in whom a cataractous lens has been
removed by phacoemulsification by extracapsular cataract extraction.
The risks associated with eye surgery and implantation of this intraocular lens included
macular edema and increased intraocular pressure. Yet there is an important benefit of
restoring sight using a biocompatible permanent implant in an eye, previously
obstructed by a cataractous lens. It is reasonable to conclude that the benefits of use of
the lens for the target population outweigh the risk of illness or injury when used as
indicated in accordance with the directions for use.
New studies with a larger cohort population and longer follow-up times are necessary
to confirm the safety and efficacy of the Mediflex IOL in the long term.
Page 12 of
12