Outcome Following Laser Peripheral Iridotomy and Predictors of Future Lens Extraction

PURPOSE To examine the outcome of laser peripheral iridotomy (LPI) for primary angle closure and determine predictors of future lens extraction (LE). METHODS A retrospective chart review of 218 eyes from 128 consecutive patients undergoing LPI between 2010 and 2012 at a university hospital. Baseline factors including age, peak intraocular pressure (IOP) before LPI, diagnosis (primary angle closure suspect, primary angle closure, primary angle closure glaucoma), and acute or non-acute presentation were recorded. Patients were followed for 3.7±1.6 years. Kaplan-Meier curves were constructed to examine survival times to LE and Cox proportional hazard regression was used to identify factors associated with LE. RESULTS In total, 91 of 218 eyes (41.7%) initially treated with LPI had LE during follow-up. For eyes with non-acute presentation, 12%, 25%, and 32% had LE at 1, 2, and 3 years, respectively. For eyes with acute presentation, 27%, 42%, and 50% had LE at 1, 2, and 3 years. In univariable analysis, older age, higher IOP, worse visual field, and primary angle closure glaucoma diagnosis were associated with LE, with older age and higher IOP remaining significant in multivariable analysis. There was a 1.09-fold increased odds of LE for each year older at baseline and each 1 mm Hg higher IOP was associated with a 1.08-fold increased odds of LE. CONCLUSIONS A large proportion of patients with angle closure treated with LPI went on to require LE. Patients with features associated with higher odds of LE might be considered for LE as a primary procedure.