Dark Adaptation in Patients with Primary Open-Angle Glaucoma, Pseudoexfoliation Glaucoma and Childhood Glaucoma.

Purpose To investigate the state of dark adaptation and macular blood flow in different forms of glaucoma. Methods Eighteen eyes of 18 patients with primary open-angle glaucoma, 14 eyes of 14 patients with pseudoexfoliation glaucoma, and 10 eyes of 10 patients with childhood glaucoma (CG) were examined by means of dark adaptometry, scanning-laser retinal flowmetry, and retinal tomography. Results All glaucomatous eyes had comparable optic disc excavation (one-way ANOVA, p = 0.138). Eyes with CG had significantly lower best-corrected visual acuity than the other groups (Tukey, all p < 0.0001). Macular perfusion was comparable in all three groups (one - way ANOVA, p = 0.08). The delay in rod-cone break time in the CG group was significantly higher than in the other groups (Tukey, all p < 0.0001). The scotopic sensitivity threshold in the CG group was significantly greater than in the other groups (Tukey, all p < 0.01). Conclusion This underlying dysfunction of dark adaptation may contribute, at least to some extent, to the decreased visual perception observed in patients with CG.

AcuFocus Corneal Inlay to Correct Presbyopia Using Femto-LASIK. One Year Results of a Prospective Cohort Study.

PURPOSE: To evaluate the safety and efficacy of the AcuFocus small aperture corneal inlay (KAMRA) for the correction of presbyopia using femto-LASIK. PATIENTS AND METHODS: This is a prospective, non-randomised cohort study including 50 presbyopic patients with hyperopia, emmetropia or mild myopia. The intracorneal inlay was implanted in the non-dominant eye using a VisuMax femtosecond laser (Zeiss 500 kHz) to create a superior-hinged flap. The inlay was centred over the visual axis. Minimum postoperative follow-up was performed for a period of 12 months. RESULTS: Fifty intracorneal inlays were implanted. At one year follow-up, the median uncorrected near visual acuity significantly improved from Jaeger (J)8 to J2 (p < 0.001). 94 % of patients could read J3 or better. The median uncorrected distance visual acuity also improved from 20/32 to 20/22 (p < 0.001). 92 % of patients could see 20/32 or better. One implant had to be recentred at four weeks follow-up. One implant was removed six months after implantation due to insufficient uncorrected near and distance visual acuity as well as slight corneal haze, which resolved four weeks later under topical treatment with fluorometholone eye drops, without any loss of best corrected distance visual acuity. No other complications occurred during the postoperative follow-up period. CONCLUSION: AutoFocus Corneal Inlay (ACI), also known as KAMRA, can provide a safe, effective and, most importantly, reversible treatment for presbyopia in hyperopic, myopic and emmetropic patients.

Controversy: Is Benzalkonium Chloride Necessary in Antiglaucoma Drops?

Medical therapy is the first-line option in glaucoma management, with benzalkonium chloride (BAC) being the most frequently used preservative in antiglaucoma medications. Its use is however, known to be associated with deleterious effects on the ocular surface. This review is an attempt to critically evaluate whether BAC really is indispensable for better bioavailability of antiglaucoma drugs and consequently, better IOP control. How to cite this article: Louati Y, Shaarawy T. Controversy: Is Benzalkonium Chloride Necessary in Antiglaucoma Drops? J Current Glau Prac 2012;6(3):104-107.

Prospective comparison of ultrasound biomicroscopy and anterior segment optical coherence tomography for evaluation of anterior chamber dimensions in European eyes with primary angle closure.

PURPOSE: To compare the accuracy in measurement of the anterior chamber (AC) angle by anterior segment optical coherence tomography (AS-OCT) and ultrasound biomicroscopy (UBM) in European patients with suspected primary angle closure (PACS), primary angle closure (PAC), or primary angle-closure glaucoma (PACG). DESIGN: Cross-sectional study. METHODS: In all, 55 eyes of 33 consecutive patients presenting with PACS, PAC, or PACG were examined with AS-OCT, followed by UBM. The trabecular-iris angle (TIA) was measured in all four quadrants. The angle-opening distance (AOD) was measured at 500 microm from the scleral spur. The Bland-Altman method was used for assessing agreement between the two methods. RESULTS: The mean (+/-SD) superior TIA was 19.3+/-15.8 degrees in AS-OCT and 15.7+/-15.0 degrees in UBM (P=0.50) and inferior TIA was 17.9+/-12.9 degrees (AS-OCT) and 16.7+/-14.1 degrees (UBM) (P=0.71). The superior AOD(500) was 0.17+/-0.16 mm in UBM and 0.21+/-0.16 mm in AS-OCT (P=0.06). Bland-Altman analysis showed a mean SD of+/-9.4 degrees for superior and inferior TIA and a mean SD of +/-0.10 mm for superior and inferior AOD(500). CONCLUSIONS: This comparative study shows that AS-OCT measurements are significantly correlated with UBM measurements but show poor agreement with each other. We do not believe that AS-OCT can replace UBM for the quantitative assessment of the AC angle.

A prospective ultrasound biomicroscopy evaluation of changes in anterior segment morphology following laser iridotomy in European eyes.

PURPOSE: The aim of this study is to quantify changes in anterior segment morphology by the use of ultrasound biomicroscopy (UBM) after Nd:YAG laser iridotomy in primary angle closure (PAC) and PAC glaucoma (PACG) in European eyes. METHODS: A total of 35 eyes of 28 consecutive patients presenting with PAC or PACG were examined by UBM at presentation, and 1 week after Nd:YAG laser peripheral iridotomy (LPI). Mean age of patients was 63.5+/-14.4 (SD) years. Seventeen patients were females (60%). The trabecular-iris angle (TIA) was measured in the superior, nasal, inferior, and temporal quadrants. Baseline measurements were made under light and dark conditions. MAIN OUTCOME MEASURE: UBM measurements of the trabecular-iris angle (TIA) and the angle opening distance (AOD). DESIGN: Consecutive observational case series. RESULTS: All measurements were made in four quadrants. Before LPI, mean superior TIA was 3.59+/-4.5 degrees (mean+/-SD), nasal TIA was 6.37+/-4.9 degrees , inferior TIA was 9.33+/-7.6 degrees , and temporal TIA was 8.65+/-7.3 degrees in light conditions. After LPI, these values increased, respectively, to 12.58+/-6.9 degrees (P<0.05), 15.40+/-6.8 degrees (P<0.05), 16.37+/-7.4 degrees (P<0.05), and 15.95+/-11.3 degrees (P<0.05), showing a significant widening of the angle in all four quadrants. Superior AOD increased from 0.060+/-0.07 to 0.107+/-0.07 mm (P=0.09). No serious LPI-related complications were encountered. CONCLUSIONS: Dimensions of the anterior chamber angle can be significantly influenced by Nd:YAG laser iridotomy in narrow angle European eyes. UBM examination is a viable tool for the quantitative evaluation of the anterior chamber angle before and after laser iridotomy.

Coupling of HRT II and AS-OCT to evaluate corneal endothelial cell loss and in vivo visualization of the Ahmed glaucoma valve implant.

AIMS: To report corneal endothelial cell loss and in vivo visualization of the Ahmed glaucoma valve implant in eyes with refractory glaucoma. METHODS: Ten eyes underwent Ahmed valve implant surgery and were followed-up for 12 months. Data collected included intraocular pressure (IOP), number of antiglaucoma medications and surgery-related complications. At 6 and 12 months postoperatively, the intracameral length of the drainage tube (ICL) and the distance between the tube and the cornea (T-C distance), and the iris (T-I distance) were assessed using anterior segment optical coherence tomography (AS-OCT). Heidelberg cornea tomograph II (HRT II) was used to measure the corneal endothelial cell density. RESULTS: Mean (+/-SEM) preoperative IOP was 29.5+/-4 mmHg. Mean postoperative IOP was 11.6+/-2 at 12 months (P<0.01). Over a 6-month period, mean corneal endothelial loss was 7.9%+/-2.5 in the central and 7.5%+/-2.4 in the peripheral cornea (P<0.01). There was no correlation between central or peripheral corneal endothelial cell loss and the T-C, T-I distance or the ICL of the tube. CONCLUSIONS: Corneal endothelial cell loss occurs following Ahmed valve implant surgery, this appears to be multifactorial. AS-OCT and HRT II are promising methods for the follow-up of patients with a glaucoma drainage device.

Quality of diurnal intraocular pressure control in primary open-angle patients treated with latanoprost compared with surgically treated glaucoma patients: a prospective trial.

PURPOSE: To compare the intraocular pressure (IOP) diurnal fluctuations of glaucoma patients treated with latanoprost 0.005% once a day with patients with controlled IOP after deep sclerectomy or trabeculectomy. METHODS: The trial included 60 prospectively recruited subjects with primary open-angle glaucoma. The medical group consisted of 20 patients with controlled IOP (<18 mm Hg) under latanoprost 0.005% monotherapy and with no history of previous intraocular surgery or argon laser trabeculoplasty; the surgical groups included 20 patients after trabeculectomy, and 20 patients after deep sclerectomy with collagen implant (DSCI). The patients in the surgical groups had a controlled IOP without any ocular hypotensive medications. All patients underwent a diurnal tension curve (08:00-17:00/three-hour intervals), followed by a water-drinking test (WDT) with the last IOP measurement taken at 21:00 hours. The between-group differences were tested for significance by means of analysis of variance (ANOVA). RESULTS: Baseline IOP was significantly different between the trabeculectomy group (10.1 mm Hg (3.4 SD)), the DSCI group (13.9 mm Hg (2.8)) and the latanoprost group (15.5 mm Hg (2.0); p = 0.005). The average IOP during the diurnal tension curve (10.1, 13.7, and 15.7 mm Hg, respectively, for the trabeculectomy, DSCI, and latanoprost groups) differed significantly between groups (ANOVA; p<0.0001), but the variation was comparable in the three groups (ANOVA; p = 0.13). After the WDT, elevation of IOP was significantly greater among patients treated with latanoprost (p = 0.003). CONCLUSION: Trabeculectomy patients had a statistically significant lower average IOP in the diurnal tension curve compared with the other two groups. No wider variation in diurnal IOP with latanoprost compared with the surgical procedures was found. The IOP increase during the WDT was most marked in patients under latanoprost therapy.

[Dosage and kinetics of MMC release of a collagen implant used as a delivery device in glaucoma surgery in the rabbit eye]. / Dosage et cinétique de libération de mitomycine C d'un implant de collagène utilisé comme moyen d'administration lors d'une chirurgie filtrante chez le lapin.

PURPOSE: To determine the absorption and the release of mitomycin-C from a collagen implant and tissue impregnation in the anterior structures of the rabbit eye. METHODS: Determining the quantity of mitomycin-C that a collagen implant can absorb with the difference between dry and soaked weight. Mitomycin-C release was measured in vitro using spectrophotometry. The measurement was repeated using a bioassay. Ocular tissue impregnation was determined in 12 eyes of six rabbits. Sclera, implant, aqueous, and ciliary body specimens were collected for concentration measurement using HPLC from 1 to 6 h after surgery. RESULTS: The mean mitomycin-C quantity absorbed in the implant was 3.22+/-0.2 microg. In vitro release was 0.13 mg/ml after 10 min and 0.05 microg/ml at 6 h. The bioassay showed almost no antifibrotic activity in sclera. In vivo release of mitomycin-C was high from the first to the sixth hour. CONCLUSION: After filtering surgery, mitomycin-C in the collagen implant is clearly released and ocular tissues are effectively impregnated.

Intraocular pressure changes in the contralateral eye after trabeculectomy with mitomycin C.

AIM: To assess intraocular pressure (IOP) changes of the contralateral eyes of eyes undergoing trabeculectomy with mitomycin C (MMC). METHODS: Non-comparative retrospective study of 24 consecutive patients who underwent trabeculectomy with MMC that led to more than 45% reduction in IOP. In the contralateral eyes, IOP before surgery was compared with IOP 1 day and 1 month after surgery. 11 fellow eyes were under topical hypotensive therapy while 13 contralateral eyes were not (12 contralateral eyes had previous filtering surgery and one had normal tension glaucoma). No patients had systemic ocular hypotensive therapy. RESULTS: Mean IOP in all contralateral eyes decreased from 15.5 (SD 5.5) mm Hg to 12.5 (3.8) mm Hg (p<0.01), and 13.0 (4.7) mm Hg (p<0.001) 1 day and 1 month after surgery, respectively. In the 11 fellow eyes under topical ocular hypotensive therapy mean IOP was reduced from 19.5 (4.0) mm Hg to 13.5 (2.2) mm Hg (p<0.01), and 16.5 (2.8) mm Hg (p<0.05) 1 day and 1 month after surgery, respectively. In the 13 fellow eyes not under topical ocular hypotensive therapy mean IOP was reduced from 12.1 (4.2) mm Hg to 11.6 (4.7) mm Hg (p not significant) and 9.8 (3.8) mm Hg (p0.01) 1 day and 1 month after surgery, respectively. CONCLUSIONS: In the present population, a month after trabeculectomy, mean IOP in the contralateral eyes decreased independently of whether these contralateral eyes were undergoing topical ocular hypotensive therapy or not.

Deep sclerectomy in one eye vs deep sclerectomy with collagen implant in the contralateral eye of the same patient: long-term follow-up.

PURPOSE: To compare prospectively the results of deep sclerectomy (DS) vs deep sclerectomy with collagen implant (DSCI). METHODS: Randomized prospective trial involving 26 eyes (13 patients) with medically uncontrolled primary and secondary open angle glaucoma. Collagen implant was randomly assigned to one eye of each patient. RESULTS: The mean follow-up period was 49.5 (SD 20) months for the DS-treated eyes, and 56.5 (SD 14) months for the DSCI-treated eyes (P=0.4). The mean preoperative intraocular pressure (IOP) was 24.1 (SD 7) mmHg for the DS-treated eyes, and 25.3 (SD 6) mmHg for the DSCI-treated eyes (P=0.5). The mean IOP at the first postoperative day was 6.4 (SD 3) mmHg for the DS-treated eyes, and 3.7 (SD 2) mmHg for the DSCI-treated eyes (P=0.05). The mean IOP at 12 months postoperative day was 15.4 (SD 3) mmHg for the DS group, and 10.4 (SD 4) mmHg for the DSCI-treated eyes (P=0.04), while at 48 months it was 16 (SD 3) mmHg for the DS group, and 10 (SD 4) mmHg for the DSCI-treated eyes (P=0.005). Complete success rate, defined as an IOP lower than 21 mmHg without medication, was 38% (5/13 patients) at 48 months for the DS-treated eyes, and 69% (9/13 patients) for the DSCI-treated eyes. Qualified success rate: patients who achieved IOP below 21 mmHg with or without medication, was 69% (9/13 patients) at 48 months and 100% (13/13 patients) for the DSCI group. The mean number of medications was reduced from 2.4 (SD 0.8) to 1.1 (SD 1) after DS, and was reduced from 2.2 (SD 0.7) to 0.4 (SD 0.6) in the DSCI group (P=0.001). For those eyes treated with DSCI, IOP was 3.21 mmHg lower than for those treated with DS (P<0.0001). CONCLUSION: The use of a collagen implant in DS seems to enhance the success rates, provides significantly lower IOP levels, and lowers the need for postoperative medications.

Influence of non-penetrating glaucoma surgery on aqueous outflow facility in isolated porcine eyes.

PURPOSE: To investigate, in vitro, the influence of non-penetrating glaucoma surgery (NPGS) and the influence of tightly suturing the superficial scleral flap on the aqueous outflow facility of isolated porcine eyes. MATERIALS AND METHODS: The anterior chambers of 12 enucleated porcine cadaver eyes were cannulated and perfused. NPGS was performed by the same surgeon. The overall ocular aqueous outflow facilities were assessed before and after the surgical interventions of NPGS, as well as after scleral flap closure. RESULTS: The mean (SD) aqueous outflow facility, which was 0.164 (0.014) microl/min/mm Hg before surgery, increased significantly after NPGS to 1.584 (0.217) microl/min/mm Hg, p<0.001. When the superficial flap was closed, the aqueous outflow facility significantly decreased (0.754 (0.107) microl/min/mm Hg, p<0.001) but remained significantly higher than preoperatively (p<0.01). After suturing the superficial flap, the overall resistance increased to 1.625 (0.210) microl/min/mm Hg. The difference in the resistance to outflow before and after flap closure was 0.848 (0.169) microl/min/mm Hg. CONCLUSION: After NPGS suturing the scleral flap can modulate aqueous outflow resistance. The experimental set up described might provide an efficient model for the technical training of glaucoma surgeries.

Low first postoperative day intraocular pressure as a positive prognostic indicator in deep sclerectomy.

AIM: To study the possibility of using intraocular pressure (IOP) in the first postoperative day after sclerectomy as a prognostic indicator. METHODS: Non-randomised prospective trial involving 105 eyes of 105 patients with medically uncontrolled primary and secondary open angle glaucoma. Visual acuity, IOP, and slit lamp examinations were performed before and after surgery at 1 and 7 days, and 1, 3, 6, 9, 12, 18, 24, 30, 36, 48, 54, 60, and 66 months. Visual field examinations were repeated every 6 months. A split point on day 1 IOP of less than or equal to 5 mm Hg (61%) versus more than 5 mm Hg (39%) was used. The first postoperative day IOP was examined in relation to the need for subsequent Nd:YAG goniopuncture, the subsequent use of postoperative antiglaucoma medications, and as a stratification variable in the Kaplan-Meier analyses. RESULTS: The mean follow up was 43.2 (SD 14.3) months. The mean preoperative IOP was 26.8 (SD 7.7) mm Hg; the mean postoperative IOP was 5.1 (3.3) mm Hg at day 1 and 11.8 (3.1) mm Hg at month 60. Patients with IOP 5 mm Hg, the median time to failure was only 6 months (CI 2 to 9). No significant difference in postoperative antiglaucoma medications was observed. CONCLUSION: First postoperative day IOP can be considered to be a significant prognostic indicator in deep sclerectomy.

Reducing intraocular pressure: is surgery better than drugs?

Reducing IOP is presently the evidence based, most accepted and most practised therapeutical approach for glaucoma patients. Currently topical ocular hypotensive medications, with its different classes, as well as filtering surgery (trabeculectomy and non-penetrating glaucoma surgery) are in the forefront of therapeutic modalities for IOP reduction. This article looks at the potential advantages and disadvantages of topical medications versus filtering surgery. It does not directly address the question of initial treatment of glaucoma, or what is the better treatment of glaucoma, as other review articles had, but rather looks in a more specific on the pros and the cons of each in relation to IOP reduction. In other words this article deals with the situation once the decision has been made to reduce IOP.

In vitro release of mitomycin C from collagen implants.

PURPOSE: To study Mitomycin C Loaded Collagen Implant (CI) pharmacokinetics behaviour in vitro. METHODS: The CI were incubated for 15 minutes in different MMC loading solutions with the following concentrations: 0.03 mg/mL (n = 9), 0.3 mg/mL (n = 10) and 3.0 mg/mL (n = 10). The loaded CI were transferred in 100 micro L of 0.9% NaCl. Aqueous flow of 5 micro L/min was simulated. The MMC concentrations of the samples were determined by high performance liquid chromatography (HPLC). Dissolution kinetics were evaluated by a first-order process. The half-life of dissolution and the time of 95% dissolution were determined. RESULTS: The CI absorbed on average a MMC dose of 0.054, 0.530 and 6.090 micro g when incubated in the different MMC loading solutions containing 0.03 mg/mL, 0.3 mg/mL, 3.0 mg/mL of MMC, respectively. In the release experiments, the mean total dose delivered by CI was 0.0493, 0.585 and 5.291 micro g. A linear correlation between loading concentration and the estimated total dose released was demonstrated. The kinetic parameters showed a fast MMC dissolution. The half-life of the 3 series was 8.8, 10.1 and 10.5 min. CONCLUSIONS: Commercially available CI can be loaded with MMC, and could provide relatively slower release than sponge delivery of MMC. Clinical implications of these results warrants further studies.

Comparative study between deep sclerectomy with and without collagen implant: long term follow up.

AIM: To identify the value of using collagen implant in deep sclerectomy. METHODS: A prospective randomised trial of 104 eyes (104 patients) with medically uncontrolled primary and secondary open angle glaucoma. All patients had deep sclerectomy (DS), half of them with and the other half without a collagen implant (CI) sutured in the scleral bed. The main outcome measures were intraocular pressure (IOP), visual acuity, number of treatments preoperative and postoperative, and Nd:YAG goniopunctures. RESULTS: Mean follow up period was 44.5 (SD 21) months for the DS group and 43.9 (SD 14) months for the deep sclerectomy with a collagen implant (DSCI) group. The mean preoperative IOP was 23.3 (SD 7.2) mm Hg for the DS group and 25.6 (SD 4.9) mm Hg for the DSCI group. The mean IOP at the first postoperative day was 6.1 (SD 4.21) mm Hg for the DS group and 5.1 (SD 3.3) mm Hg for the DSCI group. At 48 months IOP was reduced by 40% (14 versus 23.3 mm Hg) for the DS group and by 50% (12.7 versus 25.6 mm Hg) for the DSCI group. Complete success rate, defined as IOP lower than 21 mm Hg without medication, was 34.6% (18/52 patients) at 48 months for the DS group, and 63.4% (33/52 patients) for the DSCI group. Qualified success rate; patients who achieved IOP below 21 mm Hg with or without medication, was 78.8% (41/52 patients) at 48 months and 94% (49/52 patients) for the DSCI group. The mean number of medications was reduced from 2.1 (SD 0.8) to 1.0 (SD 1) after DS, and was reduced from 2.2 (SD 0.7) to 0.4 (SD 0.6) in the DSCI group (p = 0.001) CONCLUSION: The use of a collagen implant in DS enhances the success rates and lowers the need for postoperative medication.

Aqueous dynamic and histological findings after deep sclerectomy with collagen implant in an animal model.

AIM: The use of an animal model to study the aqueous dynamic and the histological findings after deep sclerectomy with (DSCI) and without collagen implant. METHODS: Deep sclerectomy was performed on rabbits' eyes. Eyes were randomly assigned to receive collagen implants. Measurements of intraocular pressure (IOP) and aqueous outflow facility using the constant pressure method through cannulation of the anterior chamber were performed. The system was filled with BSS and cationised ferritin. Histological assessment of the operative site was performed. Sections were stained with haematoxylin and eosin and with Prussian blue. Aqueous drainage vessels were identified by the reaction between ferritin and Prussian blue. All eyes were coded so that the investigator was blind to the type of surgery until the evaluation was completed. RESULTS: A significant decrease in IOP (p<0.05) was observed during the first 6 weeks after DSCI (mean IOP was 13.07 (2.95) mm Hg preoperatively and 9.08 (2.25) mm Hg at 6 weeks); DS without collagen implant revealed a significant decrease in IOP at weeks 4 and 8 after surgery (mean IOP 12.57 (3.52) mm Hg preoperatively, 9.45 (3.38) mm Hg at 4 weeks, and 9.22 (3.39) mm Hg at 8 weeks). Outflow facility was significantly increased throughout the 9 months of follow up in both DSCI and DS groups (p<0.05). The preoperative outflow facility (OF) was 0.15 (0.02) micro l/min/mm Hg. At 9 months, OF was 0.52 (0.28) microl/min/mm Hg and 0.46 (0.07) micro l/min/mm Hg for DSCI and DS respectively. Light microscopy studies showed the appearance of new aqueous drainage vessels in the sclera adjacent to the dissection site in DSCI and DS and the apparition of spindle cells lining the collagen implant in DSCI after 2 months. CONCLUSION: A significant IOP decrease was observed during the first weeks after DSCI and DS. DS with or without collagen implant provided a significant increase in outflow facility throughout the 9 months of follow up. This might be partly explained by new drainage vessels in the sclera surrounding the operated site. Microscopic studies revealed the appearance of spindle cells lining the collagen implant in DSCI after 2 months.

Five year results of viscocanalostomy.

AIM: To prospectively study the success rate and complications of viscocanalostomy, a non-penetrating glaucoma surgery. METHODS: Prospective non-randomised consecutive case series of 57 eyes (57 patients) with medically uncontrolled primary and secondary open angle glaucoma. Viscocanalostomy was performed on all participants with injection of viscoelastic in the surgically created ostia of Schlemm's canal as well as in the scleral bed, the superficial scleral flap was loosely sutured. Intraocular pressure, visual acuity, and number of goniopunctures were measured. RESULTS: The mean follow up period was 34.1 months. The mean preoperative intraocular pressure (IOP) was 24.6 mm Hg; while the mean postoperative IOP was 5.6 mm Hg at day 1 and 13.9 mm Hg at 36 month. Patients who achieved IOP below 21 mm Hg with or without medication were 90% at 60 months, complete success rate (IOP<21 mm Hg without medication) was 60% at 60 months. 21 patients (37%) needed Nd:YAG goniopuncture postoperatively to control raised IOP, mean time for goniopuncture application was 9.4 months, mean pre-goniopuncture IOP was 20.4 mm Hg and mean postgoniopuncture IOP was 12.6 mm Hg (p <0.0001). CONCLUSION: Viscocanalostomy appears to be a promising modification of filtering surgery.