Glaucoma drainage devices: a systematic literature review and current controversies.

Glaucoma drainage devices create alternate aqueous pathways by channeling aqueous from the anterior chamber through a long tube to an equatorial plate that promotes bleb formation. Glaucoma drainage devices are being used more frequently in the treatment of glaucoma that does not respond to medications or trabeculectomy operations. In certain conditions, such as neovascular glaucoma, iridio-corneal syndrome, penetrating keratoplasty with glaucoma, glaucoma following retinal detachment surgery, and so on, it is becoming the primary operation. This review provides a systematic review of the literature and outlines the current controversies involving different glaucoma drainage devices and their design, overall surgical success, and complications following glaucoma drainage device insertion.

Comparison of double-plate Molteno and Ahmed glaucoma valve in patients with advanced uncontrolled glaucoma.

BACKGROUND AND OBJECTIVE: To compare double-plate Molteno (DPM) with the Ahmed glaucoma valve (AGV) in the treatment of eyes with complicated glaucoma. PATIENTS AND METHODS: This matched, retrospective, case-control study was based on diagnosis, number of previous operations, and age. There were 30 patients in each group and only patients with a minimum of 6 months follow up were included. Double-plate Molteno or Ahmed glaucoma valve insertion was performed on each patient to control intractable glaucoma. Success was defined as IOP <22 mm Hg and >4 mm Hg on the last two visits, a decrease of no more than 2 lines in the visual acuity, and no additional surgical intervention to control IOP. RESULTS: The Kaplan-Meier estimated probability of success at 12 and 24 months was 73% and 56% with DPM and 60% and 50% for AGV (P = 0.72). Mean IOP measured 13.36 +/- 5.2 mm Hg following DPM and 16.7 +/- 5.6 mm Hg following AGV at 12 months (P = 0.026) and 13.3 +/- 5.1 mm Hg with DPM and 19 +/- 5.8 mm Hg with AGV at 24 months (P = 0.009). Of the patients involved in the study, 83.5% exhibited hypertensive phase (HP) of AGV vs 43.5% of DPM (P = 0.04). AGV had a tendency to fail earlier (5 months +/- 7 following AGV vs 13 months +/- 13 following DPM, P = 0.07, t-test). Patients with either a second valve insertion or valve removal were 7/30 of AGV vs 1/30 in DPM (P = 0.05). Stent removal was needed by 10/30 DPM and 8/30 AGV had needling/5-FU. CONCLUSIONS: The percentage of patients free from failure was similar between the two groups at 36 months. DPM is associated with lower mean IOP in the long term compared to AGV.