Trabeculectomy with a biodegradable collagen matrix implant for glaucoma

Evidence-based recommendations on trabeculectomy with a biodegradable collagen matrix implant for glaucoma. This involves cutting a small flap in the white of the eye and putting a patch over the flap to help healing and prevent scarring. Fluid slowly drains out of the flap and the patch dissolves over time. The aim is to reduce pressure in the eye and slow or stop damage to sight. Is this guidance up to date? Next review: this guidance will be reviewed if there is new evidence or safety concerns.

XEN® Gel Stent compared to PRESERFLO™ MicroShunt implantation for primary open-angle glaucoma: two-year results.

PURPOSE: To evaluate the long-term efficacy and safety of two minimally invasive glaucoma surgery implants with a subconjunctival drainage approach: the XEN45 Gel Stent® (Xen) implant and the PRESERFLO™ MicroShunt (MicroShunt). METHODS: Retrospective comparative case series of primary open-angle glaucoma (POAG) patients with at least 6 months of follow-up after a MicroShunt or Xen implantation augmented with mitomycin C. RESULTS: Forty-one eyes of 31 patients underwent Xen implantation, and 41 eyes of 33 patients, MicroShunt implantation. Baseline characteristics were similar, except for more combined surgeries with phacoemulsification in the Xen group (37% vs. 2%). Mean baseline IOP ± standard deviation dropped from 19.2 ± 4.4 to 13.8 ± 3.8 mmHg (n = 26) in the Xen group and from 20.1 ± 5.0 to 12.1 ± 3.5 (n = 14) in the MicroShunt group at 24 months of follow-up (p = 0.19, t-test). The number of IOP-lowering medications dropped from 2.5 ± 1.4 to 0.9 ± 1.2 in the Xen group and from 2.3 ± 1.5 to 0.7 ± 1.1 in the MicroShunt group. The probability of qualified success was 73% and 79% at 24 months of follow-up for the Xen and MicroShunt groups, respectively. Postoperative complications were usually mild and self-limiting. The number of bleb needling and secondary glaucoma surgery procedures was similar in both groups; however, in the Xen group more additional MicroPulse® transscleral cyclophotocoagulation procedures were performed. CONCLUSION: Xen Gel Stent and PreserFlo MicroShunt implantations achieved comparable results in POAG eyes in terms of IOP-lowering and surgical success, with a similar high safety profile.

Long-term clinical outcomes of Ahmed valve implantation in patients with refractory glaucoma.

PURPOSE: To evaluate the long-term efficacy of intraocular pressure (IOP) reduction and complications of Ahmed Glaucoma Valve (AGV) implantation in patients with refractory glaucoma. DESIGN: Retrospective study. SUBJECTS: The study involved 302 refractory glaucoma patients who underwent AGV implantation and had a minimum follow-up of 6 months between March 1995 and December 2013. METHODS: An operation was defined as successful when (1) the postoperative IOP remained between 5 and 21 mmHg and was reduced 30% compared to the baseline IOP with or without medication, (2) there was no loss of light perception or vision-threatening severe complications, and (3) no additional filtering or aqueous drainage surgery was required. Clinical records were reviewed. MAIN OUTCOME MEASURES: IOP, anti-glaucoma medications, and complications. RESULTS: The mean follow-up period was 62.25 months (range, 6 to 190 months). The cumulative probability of success was 89% at 6 months, 81% at 1 year, 66% at 3 years, 44% at 10 years, and 26% at 15 years. IOP was reduced from a mean of 32.2 ± 10.5 mmHg to 18.6 ± 9.1 mmHg at 1 month, 15.2 ± 7.0 mmHg at 6 months, and 14.2 ± 3.5 mmHg at 15 years. Surgical failures were significantly increased when preoperative IOP was high, and when severe complications occurred after AGV implantation (P < 0.05). CONCLUSION: AGV implantation was successful for IOP control in patients with refractive glaucoma in the long term. However, the success rate of surgery decreased over time. Preoperative high IOP and severe complications related to the operation were significant risk factors for failure.

The Ahmed shunt versus the Baerveldt shunt for refractory glaucoma: a meta-analysis.

BACKGROUND: The purpose of this study was to compare the efficacy and tolerability of the Ahmed glaucoma valve (AGV) implant and the Baerveldt implant for the treatment of refractory glaucoma. METHODS: We comprehensively searched four databases, including PubMed, EMBASE, Web of Science, and the Cochrane Library databases, selecting the relevant studies. The continuous variables, namely, intraocular pressure reduction (IOPR) and a reduction in glaucoma medication, were pooled by the weighted mean differences (WMDs), and the dichotomous outcomes, including success rates and tolerability estimates, were pooled by the odds ratio (ORs). RESULTS: A total of 929 patients from six studies were included. The WMDs of the IOPR between the AGV implant and the Baerveldt implant were 1.58 [95 % confidence interval (CI): -2.99 to 6.15] at 6 months, -1.01 (95 % CI: -3.40 to 1.98) at 12 months, -0.54 (95 % CI: -4.89 to 3.82) at 24 months, and -0.47 (95 % CI: -3.29 to 2.35) at 36 months. No significant difference was detected between the two groups at any point in time. The pooled ORs comparing the AGV implant with the Baerveldt implant were 0.51 (95 % CI: 0.33 to 0.80) for the complete success rate and 0.67 (95 % CI: 0.50 to 0.91) for qualified success rate. The Baerveldt implant was associated with a reduction in glaucoma medication at -0.51 (95 % CI: -0.90 to -0.12). There were no significant differences between the AGV implant and the Baerveldt implant on the rates of adverse events. CONCLUSIONS: The Baerveldt implant is more effective in both its surgical success rate and reducing glaucoma medication, but it is comparable to the AGV implant in lowering IOP. Both implants may have comparable incidences of adverse events.

The Ahmed Glaucoma Valve in Refractory Glaucoma: Experiences in Southwest Ethiopia.

BACKGROUND: The management of refractory glaucoma is a challenging task for any glaucoma surgeon. This study is aimed to evaluate the efficacy of Ahmed Glaucoma Valve implantation in refractory glaucomas in South-West Ethiopia. METHODS: A retrospective review was conducted on the charts of consecutive patients treated with Ahmed glaucoma valve implantation at Jimma University Specialized Hospital between August 2012 and August 2014. Success was defined as Intraocular Pressure (IOP) less than 22 mm Hg and greater than 5mm Hg at 6 months, with at least 30% reduction from baseline, without medical therapy (complete success) or either with or without medication (qualified successes). RESULTS: A total of 12 eyes of 11 patients were included. The mean age of patients was 40.7 (SD= 19.0) years; 63.6% of them were males. The main types of glaucoma were pseudoexfoliative (3 eyes), uveitic (2 eyes), chronic angle closure (2 eyes) and Juvenile Open Angle (JOAG) (2 eyes). The mean IOP was reduced from preoperative level (32.75±7.14 mmHg) to (15.75 ±4.35 mmHg) at six postoperative months, (P<0.001); 66.7% eyes had complete successes while 83.3% had qualified success. Intra-operative complications were encountered in 2(16.7%) eyes, while 5/12 (41.7%) eyes had post-operative complications-hypotony (one with choroidal effusion) and progression of cataract in 2 eyes each. Hypertensive phase was diagnosed in 2(16.7%) eyes. CONCLUSION: The Ahmed glaucoma valve implant appears to be effective and relatively safe for treating complicated glaucomas with success rate comparable with those reported from other studies. KEYWORDS: Ahmed glaucoma valve, refractory glaucoma, complications, Ethiopia.

Meta-analysis of randomized controlled trials comparing EX-PRESS implantation with trabeculectomy for open-angle glaucoma.

PURPOSE: To evaluate the efficacy and safety of EX-PRESS implantation compared with trabeculectomy for uncontrolled open-angle glaucoma. METHODS: Pertinent randomized controlled trials were identified through systematic searches of the PubMed, EMBASE, and Cochrane Library. The efficacy measures utilized were the weighted mean differences (WMDs) for the intraocular pressure reduction (IOPR), the reduction in glaucoma medications, the change of visual acuity, and the relative risks (RRs) for operative success rates. The safety measures utilized were RRs for postoperative complications. The pooled effects were calculated using the random-effects model. RESULTS: Four randomized controlled trials of 292 eyes were included in this meta-analysis. The WMDs of the IOPR comparing the EX-PRESS with trabeculectomy were -0.25 (95% Cl: -3.61 to 3.11) at 6 month, 0.053 (-4.31 to 4.42) at 12 months, 0.81 (-4.06 to 5.67) at 24 months, and 0.20 (-2.11 to 2.51) at final follow-up. There was no statistically significance for IOPR at any point after surgery. There were also no significant differences in the reduction in glaucoma medications or visual acuity between the groups. The pooled relative risks comparing EX-PRESS with Trabeculectomy were 1.36 (1.11 to 1.66) for the complete operative success rate and 1.05 (0.94 to 1.17) for the qualified operative success rate. EX-PRESS and Trabeculectomy were associated with similar incidences in most complications with the exception of hyphema, with pooled RR being 0.18 (0.046 to 0.66). CONCLUSIONS: EX-PRESS implantation and trabeculectomy have similar efficacy in IOP-lowering, medication reduction, vision recovery, and qualified operative success rates. EX-PRESS associated with higher rates of complete operative success and fewer hyphema than with Trabeculectomy. However, these should be interpreted with caution because of the inherent limitations of the included studies.

[Efficacy of valve drainage devices in secondary glaucoma in patients with artificial iridolenticular diaphragm].

Results of 5 Akhmed valve implantations in patients with secondary glaucoma various time after artificial iridolenticular diaphragm implantation after concomitant iris and lens trauma were analyzed. Surgery allowed to achieve reliable IOP decrease when severe scar deformation of drainage zone of the anterior chamber prevents traditional hipotensive procedures because of their ineffectiveness. Besides visual acuity stabilization a safe performance of subsequent reconstructive procedures can become possible as well.

Ahmed glaucoma valve in post-penetrating-keratoplasty glaucoma: a critically evaluated prospective clinical study.

AIM: The aim was to evaluate the outcome of Ahmed glaucoma valve (AGV) in post-penetrating-keratoplasty glaucoma (PKPG). MATERIALS AND METHODS: In this prospective study, 20 eyes of 20 adult patients with post-PKPG with intraocular pressure (IOP) >21 mmHg, on two or more antiglaucoma medications, underwent AG (model FP7) implantation and were followed up for a minimum of 6 months. Absolute success was defined as 5 < IOP < 21 mmHg and qualified success as 5 < IOP < 21 mmHg with medications or minor procedures. RESULTS: The mean IOP decreased from 42.95 ± 10.24 to 17.69 ± 3.64 mmHg (P < 0.001) and the use of medications dropped from 2.92 to 0.39 (P < 0.001) after AGV implantation. The absolute success was achieved in 11 eyes and qualified success in 9. There was no significant change in best corrected visual acuity, graft clarity, or graft thickness. Six device-related complications occurred after AGV implantations which were successfully managed with medical or minor surgical therapy. CONCLUSIONS: Postkeratoplasty refractory glaucoma managed by AGV implantation revealed a satisfactory outcome up to 6 months of follow-up.

In vivo analysis of conjunctiva in gold micro shunt implantation for glaucoma.

AIMS: To describe the conjunctival epithelial features seen with in vivo confocal microscopy (IVCM) after gold micro shunt (GMS) implantation in the suprachoroidal space, in patients with uncontrolled glaucoma. METHODS: This was an observational case series study. Fourteen eyes of 14 consecutive glaucomatous patients with a history of multiple failed incisional surgeries followed by GMS implantation were evaluated with a digital confocal laser-scanning microscope (HRT II Rostock Cornea Module). Patients were divided into two groups: successful implantations (Group 1: eight patients, eight eyes), defined as a one-third reduction in preoperative intraocular pressure (IOP) with or without antiglaucoma medications and failed implantations (Group 2: six patients, six eyes) as a less than one-third reduction in preoperative IOP with maximal tolerated medical therapy. The examination was performed from 3 to 20 months (mean 15.4±5.4) postoperatively. Conjunctival mean microcyst density (MMD: cysts/mm(2)) and mean microcyst area (MMA: µm(2)) were the main outcome measurements. RESULTS: The mean postoperative IOP was statistically different between the two groups (p<0.05), with the values of 14.3±2.77 and 32.3±8.01 mm Hg in Groups 1 and 2, respectively. When comparing successful with failed implantation, the IVCM analysis showed a greater MMD (p<0.01) and MMA (p<0.01). Clinical evidence of filtering bleb was not found in any of the patients. CONCLUSIONS: Successful GMS implantation significantly increased conjunctival microcysts density and surface at the site of the device insertion. These findings suggest that the enhancement of the aqueous filtration across the sclera may be one of the possible outflow pathways exploited by the shunt.

In vitro flow properties of glaucoma implant devices.

PURPOSE: To develop a protocol for testing glaucoma implant devices and to use this protocol to characterize devices currently available. METHODS: The following devices were obtained: Ahmed Glaucoma Valve Implant, Baerveldt Implant, Krupin Eye Valve, Joseph Valve, and OptiMed Glaucoma Pressure Regulator. Pressure per unit time was measured in real-time during ramped pressure perfusion of the implant devices with an open-manometer system. Each device was measured during a 10 minute interval while a constant flow of fluid was pumped into the system. The open manometer allowed the resistance of the devices to generate a pressure head which was monitored by computer. Four independent runs were averaged for each device. RESULTS: The Ahmed devices demonstrated reliable valve performance with a mean opening pressure of 13.65 mm Hg, a facility flow of 1.2 microL/min/mm Hg and a closing pressure of 6.1 mm Hg. The Baerveldt devices had a mean facility flow of 7.56 microL/min/mm Hg. The Joseph devices had the most variable performance, opening from 2.05 to 6.21 mm Hg. Two of 4 Joseph devices had high facility of flow (5 microL/min/mm Hg). The Krupin devices had a mean opening pressure of 6.25 mm Hg in 3 of 4 devices. The remaining Krupin device did not exhibit valve behavior. The OptiMed device did not reveal an opening pressure, and had a mean facility of flow of 7.08 microL/min/mm Hg for high flow and 6.20 microL/min/mm Hg for low flow. CONCLUSION: An objective test protocol for glaucoma implant devices was demonstrated. All implant devices had high facility of flow compared to the normal eye and can be grouped into very high facility (Baerveldt and OptiMed), and high facility (Ahmed, Joseph and Krupin). Only the Ahmed device had consistent valve behavior. None of the devices created enough resistance to explain long-term clinical failure of glaucoma drainage device surgery.