Single long scleral tunnel technique for prevention of Ahmed valve tube exposure.

Purpose: To evaluate the outcome of single long scleral tunnel technique for the prevention of conjunctival erosions caused by the Ahmed glaucoma valve. Methods: This study was a retrospective case series that included 30 eyes of 30 patients who underwent glaucoma valve implantation surgery by the single long scleral tunnel technique. Results: The mean age of patients at the time of surgery was 52 +/- 21.6 years (range: 10-90 years). The mean visual acuity was 1.5 +/- 0.81 logMAR preoperatively. The intraocular pressure was 40.7 +/- 9.18 mm Hg (range: 25-58) before surgery that decreased significantly to 19.7 +/- 3.1 mm Hg (range: 14-25; p < 0.0001) after a mean follow-up of 37.2 +/- 5.9 months. During follow-up, no case of tube exposure was detected in patients. Conclusion: Single long scleral technique was efficacious with no occurrence of tube exposure in relatively long period of follow-up. In this method, there is no need to harvest any additional material, and in situations with limited access to patch grafts, it is performable with the minimal facilities.