Prevalence, Progression, and Impact of Glaucoma on Vision After Boston Type 1 Keratoprosthesis Surgery

PURPOSE: To report glaucoma outcomes after Boston type 1 keratoprosthesis (KPro) surgery, in particular, glaucoma prevalence, progression, and treatment. DESIGN: Consecutive, retrospective, interventional case series. METHODS: SETTING: Tertiary care institution. STUDY POPULATION: Thirty-eight eyes in 38 patients. INTERVENTION: KPro surgery. MAIN OUTCOME MEASURES: Visual acuity (VA), intraocular pressure, visual fields, optic nerve status, and glaucoma treatment. RESULTS: Glaucoma diagnosis was known before surgery in 29 patients (76%; 14 had undergone previous surgery) and was diagnosed after surgery in 34 patients (89%) after a mean +/- standard deviation of 16.5 +/- 4.7 months of follow-up. The number of patients taking intraocular pressure-lowering medications increased from 19 (50%) before surgery to 28 (76%) after surgery (P = .017). Twenty-four patients (63%) were taking at least 1 additional glaucoma medication at their most recent postoperative visit. Eight patients (21%) had glaucoma progression (visual field progression, need for surgery, or both). Fifteen patients (40%) had a cup-to-disc ratio of 0.85 or more. Five patients required glaucoma surgery. VA was limited by glaucoma in 14 patients (37%), 11 of whom had a VA of 20/200 or worse. Five such patients (13%) had a dramatic improvement in VA, then progressed to end-stage glaucoma with fixation loss. Visual fields were limited by glaucoma in 25 patients (66%; mean Swedish Interactive Threshold Algorithm Fast mean defect, -20.3 +/- 8.8 decibels; n = 18). CONCLUSIONS: Most KPro candidates have glaucoma, which may deteriorate in a subset of patients after surgery. Dramatic VA improvement after KPro surgery does not preclude the need for rigorous monitoring for glaucoma progression. A low threshold should be used to treat suspicion of even slightly elevated intraocular pressure. (Am J Ophthalmol 2012;153:267-274. (C) 2012 by Elsevier Inc. All rights reserved.)