Download 13. Deep sclerectomy with a nonabsorbable implant (T

Deep sclerectomy with T- FLUX
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DEEP SCLERECTOMY with a NON- ABSORBABLE IMPLANT (TFLUX): PRELİMİNARY RESULTS
Deep sclerectomy with T- FLUX.....................
Halil Ates, Ass. Prof., MD; Önder Üretmen; MD; Kutay Andaç, Prof., MD; S.
Sertaç Azarsız, MD.
None of the authors has a proprietary or financial interest in any product mentioned.
Corresponding address: Önder Üretmen, MD, Ege University School of Medicine,
Department of Ophthalmology, 35100, Bornova-Izmir, TURKEY
Tel. + 90-232-3881469
Fax. + 90-232-3881469
E-mail. [email protected]
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1
All authors are from Ege University School of Medicine, Department of Ophthalmology,
35100, Bornova-Izmir, TURKEY
Deep sclerectomy with T- FLUX
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ABSTRACT:
DEEP SCLERECTOMY with a NON- ABSORBABLE IMPLANT (T- FLUX):
PRELİMİNARY RESULTS
Background: We aimed to determine the efficacy, success rate and complications of
deep sclerectomy with a non- absorbable implant (T- Flux, IOLTECH, France) in this
prospective study.
Methods: Twenty- five patients (25 eyes) with medically uncontrolled open angle
glaucoma were treated by deep sclerectomy with T- Flux. Intraocular pressure (IOP) reduction,
surgical success and complication rates were evaluated.
Results: After a mean follow up of 16.21± 3.93 months, the mean preoperative IOP
reduced from 26.26±4.3 mmHg to 17.60±4.35 mmHg at the last visit (p= 0.000). Complete
success rate (IOP< 21mmHg without medication) was 86.9 % at 1 month, 56.5 % at 12 months
and 39.1 % at the last postoperative visit. Qualified success rates (IOP< 21mmHg with or
without medication) were 95.6%, 91.3 % and 82.6 % respectively. No postoperative
complications, regarding the probable complications of trabeculectomy, was observed. Three
eyes underwent goniopunctures with Nd:YAG laser.
Interpretation: A statistically significant drop of IOP with few postoperative
complications over short term could be achieved with this technique. Success rates were
comparable but not more successful than viscocanalostomy.
Deep sclerectomy with T- FLUX
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Trabeculectomy is currently the standard filtration procedure for surgical treatment of
glaucoma. However, this technique can cause severe postoperative complications such as
hyphema, shallow or flat anterior chamber, hypotony with the risk of choroidal detachment, and
maculopathy. In order to lower the risk of these complications while retaining the efficacy of
trabeculectomy, non- penetrating glaucoma filtering procedures are described in recent years.
The two major variations of non- penetrating glaucoma surgery for open angle glaucoma are
deep sclerectomy and viscocanalostomy.1
In deep sclerectomy procedure, a deep scleral flap is created and removed including the
outer wall of Schlemm’s canal and the limbal cornea over Descemet’s membrane. Aqueous
humour percolates through the Descemet membrane, anterior trabeculum and unroofed
Schlemm’s canal. Deep sclerectomy lowers intraocular pressure (IOP) without perforation of the
anterior chamber. It is suggested that placing an implant in the scleral bed could to enhance the
filtration and prevent the collapse of the scleral space created during deep sclerectomy. Kozlov et
al 2 and Fyodorov3 described the use of a collagen implant placed within the scleral bed. As an
alternative, Sourdille et al. described placing a reticulated hyaluronic acid implant.4 It has been
showed that these two implants are absorbed by time.4-6 Another available implant is a nonabsorbable one which is made up of hydrophilic acrylic [Dahan E et al., presented at the First
International Congress on Non- Penetrating Glaucoma Surgery, 2001].
To date, there is not enough data showing the safety and the efficacy of deep sclerectomy
with this non- absorbable hydrophilic acrylic implant. Hence, we aimed to determine the success
rate and complications of this procedure in this prospective study.
Deep sclerectomy with T- FLUX
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Methods:
We enrolled 25 eyes of 25 patients (16 male, 9 female; all white) with medically
uncontrolled open angle glaucoma. The indications for surgery while patients were undergoing
maximally tolerated medical therapy (2 antiglaucoma medications) were 1) uncontrolled IOP
such that the examining physician’ s (H.A) opinion placed the patient at high risk of glaucoma
progression 2) worsening of the visual field as judged by examining physician 3) deterioration of
optic disc as judged by examining physician. Exclusion criteria were unwillingness to
participate, one- eyed patients and known allergy to acrylic. Informed consent was obtained from
all participants.
Twelve of 25 eyes (48 %) had pseudoexfoliative glaucoma and the remainder (%52) had
primary open angle glaucoma. The mean age of the patients was 61.1±11 years (range 32 to 76
years). None of the patients underwent ocular surgery previously.
Before surgery, all patients underwent best corrected visual acuity assessment (Snellen
chart), biomicroscopy, gonioscopy, applanation tonometry with the Goldmann tonometer, visual
field testing using the threshold 30-2 program of the Humphrey Field Analyzer and fundus
examination including optic nerve head evaluation. Lens opacities were graded by the Wilmer
system subjectively. Surgery related cataract was defined by rapid decrease (1 month) of visual
acuity and mainly development of cortical opacity. Refractive status of the patients were
determined by using a standart autorefractometer. After surgery the same examinations, except
for visual fields, were performed at postoperative days 1st, 7th, 15th, 30th and every four weeks
thereafter.
Visual field examination was done every 6 months. Visual field defects were classified as
early, moderate or severe according to the model of Hodapp et al.7 Judgement of postoperative
progression of field defects was based on the system of Budenz.8
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Deep sclerectomy with T- FLUX
All patients underwent deep sclerectomy with non- absorbable implant (T- Flux,
IOLTECH, France) under topical anesthesia with Bupivacaine HCl (Marcaine) 0.5% soaked
sponge. For deep sclerectomy, a scleral flap measuring 5mm by 5mm was created in
approximately 1/3 thickness after opening the conjunctiva in the upper fornix. Underneath the
flap, a deep sclerectomy measuring 4mm by 4mm was performed. Observing the leakage of
aqueous humor through the unroofed Schlemm’s canal, the two arm extremities of the nonabsorbable hydrophilic acrylic implant (T- Flux, IOLTECH, France) were anchored into
Schlemm’ s canal and the implant was secured to the deep sclera by placing a 10/0 nylon suture.
The implant is made of poly- megma and has a arm length and body height of 4.00mm and
2.75 mm respectively (Figure 1). The scleral flap was closed on the implant and sutured with two
10/0 nylon sutures, and the conjunctiva was closed with 8/0 silk sutures. Antimetabolites were
not used peroperatively or postoperatively.
When the trabeculo- Descemet’ s membrane
perforated during corneal stroma dissection the surgery was converted to a standart
trabeculectomy. These patients were excluded from the analysis. Postoperatively, the patients
were started on a topical regimen of Dexamethasone %1 q.i.d and Gentamycine %0.3 q.i.d for 7
days. Only Dexamethasone %1 q.i.d was continued for 2 months.
We used the following four definitions for successful IOP control by deep sclerectomy
with T- Flux: 1) IOP < 21mmHg without glaucoma medication plus a 30% or more reduction
in IOP (full complete success) 2) IOP < 21mmHg without glaucoma medication (complete
success) 3) IOP < 21 mmHg with or without medication plus a 30% or more reduction in IOP
(full qualified success) 4) IOP < 21 mmHg with or without medication (qualified success).
Treatment with two antiglaucomatous medications was considered as maximally tolerated
medical therapy. When the patients did not meet the success definition on two consequtive visits,
their cases were defined as failures.
Deep sclerectomy with T- FLUX
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In order to evaluate the efficacy of this new implant in detail, we have constituted a
control group of patients who had undergone successful viscanalostomy in our institution. We
have selected 26 matching subjects based on their age, sex, diagnosis, preoperative IOP, number
of preoperative antiglaucoma medications and previous ocular surgeries. We have compared the
success rates of these two treatment modalities based on the above mentioned definitions for
successful IOP control.
For statistical analysis, Wilcoxon signed- rank test, chi- square test and Mann Whitney- U
test were used; p < 0.05 was considered statistically significant.
Results:
As the surgery was converted to a standart trabeculectomy due to the trabeculoDescemet’ s membrane perforation during corneal stroma dissection in two eyes, a total of 23
eyes were included in the analysis of the results. The mean follow-up was 16.21±3.93 months
(range 12 to 22 months). All patients completed 12 months follow up.
The mean preoperative IOP was 26.26±4.3 mmHg (range 22 to 34 mmHg) and decreased
to 17.6±4.35 (range 11- 30 mmHg) at the last postoperative visit. The difference between the
preoperative IOP level and IOP measured at each postoperative visit was found to be statistically
significant (Wilcoxon signed- rank test, p=0.000) (Figure II).
The mean number of medications per patient, which was 2.17±0.83 preoperatively, was
0.91±0.9 at the last post- operative visit (Wilcoxon signed- rank test, p= 0.001). The number of
antiglaucomatous medications used pre- operatively and post- operatively at each follow- up visit
was presented in Figure III.
The mean best corrected Snellen visual acuity (BCVA) was 0.76 (range 0.2 to 1.0)
preoperatively and 0.72 (range 0.2 to 1.0) postoperatively at 12 months (Wilcoxon signed- rank
Deep sclerectomy with T- FLUX
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test, p>0.05). Visual acuity remained stable over the entire follow up period in all patients. No
patient lost two or more Snellen lines of BCVA.
Judgement of the glaucomatous progression with the system of Budenz [8] revealed that
none of the patients developed additional visual field defects postoperatively. Deterioration of
optic disc was not observed in any patients.
Three eyes in which IOP reduction was considered to be insufficient after the operation
underwent goniopunctures with Nd:YAG laser. However, this procedure was not effective to
control the IOP. Hence, one of them were started on topical antiglaucomatous medications. The
other two patients underwent subsequent trabeculectomy and considered as failures.
Auto kerato- refractometric analysis of the patients revealed that placing a nonabsorbable implant in the scleral bed did not induce considerable astigmatism requiring further
correction.
Apart from the trabeculo- Descemet’ s membrane perforation in two eyes, there were no
significant intraoperative complications. Detailed examination revealed no postoperative
complications regarding the probable complications of trabeculectomy such as anterior segment
inflammation, shallowed anterior chamber, hyphema, hypotony or endophthalmitis. Only, dellen
formation was observed in one patients and treated with topical lubricating drops. Surgeryinduced cataract or progression of a preexisting senile cataract did not occur in any patients.
Statistical analysis of the success rates revealed that deep sclerectomy with T- Flux is
comparable to viscocanalostomy at all post- operative visits (chi- squre test, p> 0.05). The
success rates of these two proceduress based on the definition for successful IOP control were
shown in Table 1.
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Discussion:
Non- penetrating filtration procedures are alternatives to trabeculectomy with the
advantage of minimizing the risk of postoperative complications. They have evolved into two
variations, deep sclerectomy and viscocanalostomy. The major advantage of these procedures is
that they preclude the sudden hypotony that occurs after trabeculectomy by creating progressive
filtration of aqueous humor from the anterior chamber to the subconjunctival space without
perforating the eye [9].
The use of various implants in deep sclerectomy was advocated to maintain the space
created by the removal of the deep sclerocorneal flap. Chiou et al [6] performed ultrasonic
biomicroscopy in patients who underwent deep sclerectomy with collagen implant. Their
findings were consistent with IOP lowering by aqueous filtration through the thin remaining
trabeculo- Descemet’ s membrane to an area under the scleral flap, which was hypothetically
kept open by the presence of the collagen implant. The authors stated that the collagen implant
dissolved slowly within 6 to 9 months and was replaced by new autologous scleral tissue, leaving
a tunnel in the sclera.. Sanchez et al. [10] compared the effectiveness of deep sclerectomy with
and without collagen implant and concluded that the collagen implant device increased the
success rate of deep sclerectomy. Contrary to these, Demailly et al. [11] stated that collagen
device did not seem to improve tonometric results at middle term. Although the role of an
implant in enhancement of the filtration could make sense, these conflicting clinical results have
to be confirmed by a randomized comparative study.
T- Flux is a hydrophilic acrylic non- absorbable implant. Theoretically, placing a nonabsorbable implant could create a permanent intra- scleral space by preventing adhesion between
the scleral flap and the scleral bed. Besides, the implant is supposed to be in direct contact with
Deep sclerectomy with T- FLUX
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the filtering trabeculum and to stimulate the formation of new aqueous veins. A valid conclusion
on this hypothesis can be made after any histologic or ultrasound biomicroscopic analysis of
human eyes operated with this new implant are presented.
Dahan et al. reported that the IOP dropped from an average preoperative value of
23.47mmHg with 2.8 antiglaucomatous medication to 11.78mmHg (50%) without any
medication after non- penetrating glaucoma surgery with the use of T- Flux [Dahan et al.,
presented at the First International Congress on Non- Penetrating Glaucoma Surgery, 2001]. In
our series, we achieved a statistically significant IOP drop throughout the follow- up period
compared to preoperative levels. The mean percentage reduction in IOP compared to
preoperatively was 32.9 % at the last post- operative visit. Our complete success rate (IOP
<21mmHg without medication) was 56.5 % at 12 months and 39.1 % at the last postoperative
visit. However, we also determined that both mean IOP levels and the number of medications
used had a tendency to increase throughout the study which had to be followed up closely in the
long term.
The success rate of non- penetrating surgeries with or without implants varied widely in
various published papers. It is known that differences in surgical technique itself and differences
in criteria of success could be the main explanations for the variability of success rate. Thus, the
only way to evaluate the usefulness of the implants is to provide a comparative study with case
controls; otherwise, it could be hard to make valid conclusions.
Most of the surgical maneuvers are common in deep sclerectomy with T- Flux and
viscocanalostomy. In viscocanalostomy, high viscosity sodium hyaluronate was injected into the
Schlemm’ s canal without placing an implant. In deep sclerectomy with T- Flux, the implant
was secured to the deep sclera after the two arm extremities of the implant had been anchored
Deep sclerectomy with T- FLUX
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into Schlemm’ s canal. These two procedures are the only non- penetrating glaucoma surgery
techniques in which a direct intervention into the Schlemm canal was accomplished. Hence, we
compared the success rates of these two procedures in order to make a valid conclusion.
Statistical analysis revealed that there was not any significant difference between these two
techniques at all post- operative visits in respect to the success rates. We determined that deep
sclerectomy with T- Flux was comparable but not more successful than viscocanalostomy in
achiveing the above mentioned definitions of successful IOP control.
In both deep sclerectomy and viscocanalostomy, non- penetration of the anterior chamber
allowed a gradual and progressive decrease of IOP and thus common peroperative and
postoperative complications of classical trabeculectomy are markedly reduced [12-15].
Similarly, we did not observe any postoperative flat anterior chamber, hyphema or anterior
chamber inflammation in our series.
Glaucoma filtration surgery can result in loss of visual acuity by the increase in the
degree of lens opacification, maculopathy due to hypotonia and wipe- out [16]. However, after
deep sclerectomy, it is uncommon to have a change in visual acuity [17]. We did not find any
statistically significant difference between the mean pre and postoperative Snellen visual acuity
of our patients.
Mermoud et al. [18] reported that 41% of 100 eyes had to undergo Nd:YAG laser
goniopuncture after DSCI. The success rate of the procedure was 83% at the end of two years.
Hamard et al. [19] determined that goniopuncture had to be performed in more than one third of
cases after DSCI and was effective to control IOP in half of the cases. In our study, we had to
perform Nd:YAG laser goniopuncture in three eyes. As IOP did not decrease to acceptable levels
after the procedure, one of them were started on a topical antiglaucomatous regimen and the
Deep sclerectomy with T- FLUX
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others underwent subsequent trabeculectomy.
It is clear that deep sclerectomy with a non- absorbable implant has some disadvantages.
As this is a more challenging procedure technically compared to the trabeculectomy, it needs
much more experience. In our series, we had to convert the procedure to a standart
trabeculectomy due to the trabeculo- Descemet’ s membrane perforation during corneal stroma
dissection in 2 (8%) eyes. Also, the cost of the implant is a major problem.
As far as we know, this is the first report evaluating efficacy, success rate and
complications of deep sclerectomy with T- Flux. We achieved a significant drop of IOP over
short term with this technique. However, deep sclerectomy with T- Flux was comparable but
not more successful than viscocanalostomy in achiveing successful IOP control. In order to
ascertain the appropriate option in different categories of glaucoma patients, controlled
prospective studies comparing this technique with other non- penetrating filtration procedures
and standart trabeculectomy are necessary.
References:
1. Lachkar Y, Hamard P. Nonpenetrating filtering surgery. Curr Opin Ophthalmol 2002;13:110-
5.
2.
Kozlov VI, Bagrov SN, Anisimova SY. Non penetrating deep sclerectomy with collagen.
Eye Microsurgery 1990; 3,44-6.
3. Fyodorov SN. Non penetrating deep sclerectomy in open- angle glaucoma. Eye Microsurgery
1989;2:52-5.
4. Sourdille P, Santiago PY, Villain F, Yamamichi M, Taki H, Parel JM, Ducournau Y.
Reticulated hyaluronic acid implant in nonperforating trabecular surgery. J Cataract Refract
Surg 1999;25:332-9.
Deep sclerectomy with T- FLUX
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5. Marchini G, Marraffa M, Brunelli C, Morbio R, Bonomi L. Ultrasound biomicroscopy and
intraocular- pressure lowering mechanisms of deep sclerectomy with reticulated hyaluronic
acid implant. J Cataract Refract Surg 2001;27:507-17.
6. Chiou AG-Y, Mermoud A, Underdahl JP, Schnyder CC. An ultrasound biomicroscopic study
of eyes after deep sclerectomy with collagen implant. Ophthalmology 1998;105:746- 50.
7. Hodapp E, Parrish RK, Anderson DR. Clinical decisions in glaucoma. St. Louis: Mosby,
1993: 56
8. Anderson DR. Automated static perimetry. St Louis: Mosby- Year book 1992:182.
9. Hamel M, Shaarawy T, Mermoud A. Deep sclerectomy with collagen implant in patients
with glaucoma and high myopia. J Cataract Refract Surg 2001;27:1410-7.
10. Sanchez E, Schnyder CC, Sickenberg M, et al. Deep sclerectomy: results with and without
collagen implant. Int Ophthalmol 1996;20:157-62.
11. Demailly P, Lavat P, Kretz G, Jeanteur-Lunel MN. Non-penetrating deep sclerectomy with
or without collagen device in primary open angle glaucoma:middle-term retrospective study.
Int Ophthalmol 1996-97; 20:131-40.
12. Shaarawy T, Karlen M, Schnyder C, Achache F, Sanchez E, Mermoud A. Five-year results
of deep sclerectomy with collagen implant. J Cataract Refract Surg 2001;27:1770-8.
13. Mermoud A,
Schnyder CC, Sickenberg M, Chiou AG, Hediguer SE, Faggioni R.
Comparison of deep sclerectomy with collagen implant and trabeculectomy in open-angle
glaucoma. J Cataract Refractive Surg 1999, 25:323-31
14. Sunaric- Megevand G, Leuenberger PM. Results of viscocanalostomy for pirmary open-
angle glaucoma. Am J Ophthalmol. 2001; 132: 221-8.
Deep sclerectomy with T- FLUX
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15. Stegmann R, Pienaar A, Miller D. Viscocanalaostomy for open- angle glaucoma in black
African patients. J Cataract Refract Surg 1999; 25: 316-22.
16. Costa VP, Smith M, Spaeth GL, Gandham S, Markowitz B. Loss of visual acuity after
trabeculectomy. Ophthalmology 1993; 100 (5):599-612.
17. Demailly P, Jeanteur-Lunel MN, Berkani M, Ecoffet M, Kopel J, Kretz G, Lavat P. Non
penetrating deep sclerectomy combined with a collagen implant in primary open angle
glaucoma. Medium term retrospective results. J Fr Ophthalmol 1996; 19: 658-666
18. Mermoud A, Karlen ME, Schnyder CC, Sickenberg M, Chiou AG, Hediguer SE, Sanchez E.
Nd:Yag goniopuncture after deep sclerectomy with collagen implant. Ophthalmic Surg Laser
1999, 30:120-5.
19. Hamard P, Plaza L, Kopel J, Quesnot S, Hamard H. Deep nonpenetrating sclerectomy and
open angle glaucoma. Intermediate results from the first operated patients. J Fr Ophthalmol
1999, 22:25-31.
Key words: deep sclerectomy, glaucoma, intraocular pressure, surgery, T- Flux
Legends for Figures:
Figure I. Schematic drawing of the non- absorbable implant (T- Flux)
Figure II. Intraocular pressure changes throughout the follow up period after deep sclerectomy
with T- Flux.
Figure III. Number of antiglaucoma medications used throughout the follow up period after
deep sclerectomy with T- Flux.
Deep sclerectomy with T- FLUX
Figure I.
14
15
IOP (mmHg)
Deep sclerectomy with T- FLUX
30
25
20
15
10
5
0
26,26
Pre- op
14,56
15,69
16
17,6
1 mo.
6 mo.
12 mo.
Last visit
Follow up period
Figure II.
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Number of medications
Deep sclerectomy with T- FLUX
2,50
2,00
2,26
1,50
0,91
1,00
0,50
0,13
0,00
Pre- op
1 mo.
0,17
6 mo.
0,56
12 mo.
Follow up period
Figure III.
Last visit
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Deep sclerectomy with T- FLUX
Post- op 1 month
Post- op 6 months
Post- op 12 months
Last visit
T- Flux
Visco
T- Flux
Visco
T- Flux
Visco
T- Flux
Visco
Full complete success
78.2%
65.3 %
56.5 %
57.6 %
43.4 %
42.3 %
30.4 %
30.7 %
Complete success
86.9 %
76.9 %
78.2 %
69.2 %
56.5 %
65.3 %
39.1 %
50 %
Full qualified success
82.6 %
84.6 %
73.9 %
76.9 %
69.5 %
65.3 %
56.5 %
69.2 %
Qualified success
95.6 %
96.1 %
95.6 %
88.4 %
91.3 %
88.4 %
82.6 %
88.4 %
P value (chi- square test)
p > 0.05
p > 0.05
p > 0.05
p > 0.05
* post- op: post- operative; ** visco: viscocanalostomy
Table I. Success rates of deep sclerectomy with T- Flux and viscocanalostomy based on the definition for successful IOP
control.
Deep sclerectomy with T- FLUX
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