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Impervious encapsulation around Ahmed glaucoma valve (AGV) results in surgical failure raising intraocular pressure (IOP). Dysregulation of extracellular matrix (ECM) molecules and cellular factors might contribute to increased hydraulic resistance to aqueous drainage. Therefore, we examined these molecules in failed AGV capsular tissue. Immunostaining for ECM molecules (collagen I, collagen III, decorin, lumican, chondroitin sulfate, aggrecan and keratan sulfate) and cellular factors (αSMA and TGFβ) was performed on excised capsules from failed AGVs and control tenon's tissue. Staining intensity of ECM molecules was assessed using Image J. Cellular factors were assessed based on positive cell counts. Histopathologically two distinct layers were visible in capsules. The inner layer (proximal to the AGV) showed significant decrease in most ECM molecules compared to outer layer. Furthermore, collagen III (p = 0.004), decorin (p = 0.02), lumican (p = 0.01) and chondroitin sulfate (p = 0.02) was significantly less in inner layer compared to tenon's tissue. Outer layer labelling however was similar to control tenon's for most ECM molecules. Significantly increased cellular expression of αSMA (p = 0.02) and TGFβ (p = 0.008) was detected within capsular tissue compared to controls. Our results suggest profibrotic activity indicated by increased αSMA and TGFβ expression and decreased expression of proteoglycan (decorin and lumican) and glycosaminoglycans (chondroitin sulfate). Additionally, we observed decreased collagen III which might reflect increased myofibroblast contractility when coupled with increased TGFβ and αSMA expression. Together these events lead to tissue dysfunction potentially resulting in hydraulic resistance that may affect aqueous flow through the capsular wall.

Purpose: Encapsulation of the Ahmed glaucoma valve (AGV) plate is a common cause for postoperative elevation of intraocular pressure, especially in children. Many reports have described the outcomes of AGV revision in adults. However, the outcomes of AGV revision in children are poorly documented. The aim of this study was to determine the outcomes of AGV revision in children., Design: Retrospective cross-sectional study., Methods: A retrospective chart review of patients less than 15 years of age who underwent AGV revision with a minimum postoperative follow-up of 6 months was conducted. Outcome measures included reduction in intraocular pressure from baseline, survival analysis, and reduction in the number of antiglaucoma medications. Postoperative complications were also noted. Complete success was defined as an IOP of 21 mm Hg or less without medications, while qualified success was defined as having an IOP of 21 mm Hg or less with medications., Results: A total of 44 eyes met the inclusion criteria. Primary congenital glaucoma was present in 39 eyes (88.6%), aphakic glaucoma in 4 eyes (9.1%), and Peters anomaly-associated glaucoma in 1 eye (2.3%). The mean number of previous surgeries was 1.4, and the mean age was 6.7 years (range, 1.9-13 years) with a median follow-up of 12 months (range, 6-24 months). The IOP was reduced from a preoperative mean of 30.4 (± 10.3) to 24.9 (± 10.6) mm Hg at 6 months postoperatively. Kaplan-Meier analysis showed that the complete success rate at 1 month was 100% followed by a rapid decline at 6 months to 38.6%, 27.7% at 1 year, and 5.5% at 2 years. Qualified success rate was 100% at 1 month followed by a 6-month and 1-year survival rate of approximately 50% and a 2-year survival rate of approximately 16%. The median survival time was 14 months. No specific risk factors for failure were identified. Visual acuity remained unchanged following revision. The most common complication was recurrence of encapsulation with elevated IOP (15.9%). Other complications included hyphema (n = 3; 6.8%), endophthalmitis (n = 1; 2.3%), wound leak (n = 1; 2.3%), and choroidal detachment (n = 2; 4.5%)., Conclusion: Although the short-term success rate of AGV revision in children is high, with longer follow-up the success rate decreases significantly., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Purpose: To determine the prevalence and risk factors for escalation of glaucoma therapy after penetrating keratoplasty (PK) and its impact on graft survival and visual outcome., Design: Retrospective case series., Participants: Seven hundred fifteen consecutive eyes of 678 patients undergoing PK., Methods: Retrospective review of every case of PK performed at King Khaled Eye Specialist Hospital between January 1, 2001 and December 31, 2002., Main Outcome Measures: Escalation of glaucoma therapy, graft survival, and visual outcome., Results: Escalation of glaucoma therapy occurred in 89 (12.4%) eyes of 715 PK procedures during a mean follow-up of 32.2 months. Medical escalation accounted for 73 (82.0%) cases, whereas surgical escalation occurred in 16 (18.0%) eyes. The following were significantly associated with an increased risk of escalation of glaucoma therapy: surgical indication for PK (P<0.001), increasing patient age (P<0.001), preexisting glaucoma (P<0.001), recipient trephination < 7.0 mm (P = 0.02), and pseudophakia or aphakia (P<0.001). Eyes with escalation of glaucoma therapy had significant reduction in graft survival compared with eyes in which this did not occur (52.8% vs. 82.9%, P<0.001). Escalation of glaucoma therapy was associated with a significant reduction in the percentage of eyes achieving visual acuity of 20/40 or better (9.0% vs. 42.1%, P<0.001) and a significant increase in those obtaining 20/200 or worse (70.8% vs. 26.7%, P<0.001)., Conclusions: Escalation of glaucoma therapy is a serious sequela of PK that is significantly associated with an increased risk of graft failure and poor visual outcome.

Purpose: To study the long-term outcomes of surgical revision of leaking blebs after trabeculectomy and identify possible risk factors for failure., Patient and Methods: A retrospective, nonrandomized, noncomparative interventional study of 34 eyes with late bleb leaks after trabeculectomy that underwent bleb excision with conjunctival advancement. The primary outcome measure was successful repair and control of intraocular pressure (IOP). The other measures evaluated included change in visual acuity from baseline and complications such as recurrence of bleb leak, endophthalmitis or the need for additional antiglaucoma medication to control IOP., Results: After a mean follow up of 36.2+/-23 months, the mean IOP at the last visit was 14.5+/-7.6 mm Hg. IOP in 58.8% of eyes was controlled without medication. Complications included early leaks (7/34), late recurrent or persistent leaks (1/34), and endophthalmitis (1/34). In all, 41.2% patients required additional medication at the last visit. Survival analysis at 22 months the probability of total and qualified success was 52% and 72%, respectively. However, this dropped to 10% and 15%, respectively, at 5 years. The probability of total and qualified success further dropped to 2.5% and 5% at 5 years when the IOP cut-off was lowered from 21 to 15 mm Hg. Cox regression analysis failed to identify risk factors for bleb failure., Conclusions: Surgical bleb revision seems to be effective in treating late bleb leaks with few postoperative complications. However, patients should be followed carefully as late failure of bleb function beyond 2 years is a significant possibility.