Ahmed glaucoma valve tube erosion A retrospective review of autologous scleral flap versus donor scleral graft

Abstract

Objective: This study determined the rates of tube erosion and associated complications among patients implanted with the Ahmed glaucoma valve (AGV) using autologous scleral flap versus donor scleral graft.

Methods: The clinical records of consecutive patients who underwent AGV implantation using either autologous scleral flap or donor scleral graft between August 2001 and April 2006 with a minimum follow-up of four months were reviewed. Data were collected using a standardized form and subjected to statistical analyses.

Results: A total of 25 eyes of 25 consecutive patients who underwent AGV implantation were included. Fourteen received donor scleral grafts and 11 autologous scleral flaps. There were no tube erosions in the autologous scleral group. Transconjunctival erosion was seen in 71% of eyes in the donor scleral group, half of them occurring during the first 3 months postoperatively. Two eyes with erosion developed endophthalmitis.

Conclusion: The use of autologous scleral flap in AGV implantation appears to be an effective technique in preventing transconjunctival tube erosions. Exposure of the tube is a major risk factor in the development of endophthalmitis.