Outcomes of Laser Peripheral Iridotomy in Angle Closure Disease

Abstract

Purpose: To evaluate the long-term outcomes of laser peripheral iridotomy (LPI) in primary angle closure disease.Methods: We retrospectively reviewed the medical records of all Indian subjects of primary angle closure (PAC) and primary angle closure glaucoma (PACG) who underwent LPI between 2003 and 2004. Subjects requiring additional treatment in the form of antiglaucoma medications or trabeculectomy during the follow-up were identified. Baseline factors predicting the need for additional treatment following LPI in primary angle closure disease (PAC+PACG) were analyzed.Results: 84 eyes (PAC:PACG = 16:68) of 47 subjects had undergone LPI during the study period. Over a mean follow-up of 50 ± 22.7 months, 68 eyes (PAC:PACG = 9:59) required additional treatment, of which 26 eyes (PAC:PACG=2:24) subsequently underwent trabeculectomy. Over the initial 20 months of follow-up after LPI, the cumulative probability of requiring no additional treatment was similar between PAC [63.6% (95% CI: 29.7–84.5)] and PACG eyes [64.0% (95% CI: 44.5–78.3)]. Subsequently, the cumulative probability of requiring no additional treatment in PACG eyes dropped to 24.8% (9.7–43.5) at 4 years and 9.9% (1.8–26.7) at 7 years. Presenting IOP (p = 0.01) and highest recorded IOP before LPI (p = 0.03) were the most significant predictors of the need for additional treatment after LPI. Extent of synechial angle closure (p = 0.04) and the cup to disc ratio (p = 0.05) significantly predicted the need for trabeculectomy subsequently in PACG eyes.Conclusions: The majority of angle closure eyes required additional treatment after LPI. Eyes with a higher presenting IOP were more likely to require additional treatment and those with a greater amount of synechial angle closure and larger cup disc ratio at presentation were more likely to require surgery over the follow-up.