Bleb revision for hypotony maculopathy after trabeculectomy.

Abstract

To assess the efficacy of a bleb revision technique with regard to improvement in intraocular pressure (IOP) and visual acuity after hypotony maculopathy and to evaluate the influence of duration of hypotony on visual outcome. : Retrospective review of a series of patients who underwent bleb revision for hypotony maculopathy (IOP less than 6 mm Hg and loss of two or more lines of central vision) following trabeculectomy. Bleb revision included excision of avascular bleb tissue, dissection posteriorly between conjunctiva and Tenon's capsule, and advancement and suturing of the conjunctiva at the limbus. Fourteen patients were included in the study. The average age was 49.8 years (range 18-85) and eight were female. Before trabeculectomy, the mean IOP was 23.2 +/- 11.8 mm Hg, and the visual acuity was 20/30-2 or better in 13 patients and 20/80 in one patient. The mean IOP before bleb revision was 1.07 +/- 0.73 mm Hg, and 12 patients had lost an average of 4.33 +/- 2.96 lines of visual acuity from baseline, while one had count fingers and another had hand motion vision. The final mean IOP after bleb revision was 11.07 +/- 3.08 mm Hg. Compared with visual acuity just prior to bleb revision, 12 patients regained an average best corrected vision of 3.08 +/- 2.67 lines, with seven returning to the pre-trabeculectomy vision level. The duration of hypotony prior to bleb revision was 1 to 24 months (average 8.36 months) with no correlation (correlation coefficient -0.13) between duration and visual outcome. Bleb revision for hypotony maculopathy following trabeculectomy is an effective technique for raising IOP and limiting visual loss, which is not influenced by duration of hypotony within the time frame of the study.