Correlation Between Extent of Preexisting Organic Angle Closure and Long-term Outcome After Laser Peripheral Iridotomy in Eyes With Primary Angle Closure

Abstract

To investigate the long-term clinical course of eyes with primary angle closure (PAC) after laser peripheral iridotomy (LPI), and to determine whether there is a significant correlation between the extent of a pre-existing peripheral anterior synechiae (PAS) and the intraocular pressure (IOP). We retrospectively examined the course of 107 consecutive eyes with occludable angles after LPI. An organic angle closure was identified by indentation gonioscopy. The eyes were assigned into 3 groups: primary angle-closure suspect (PACS), PAC with PAS below 2 quadrants (PAC1), and PAC with PAS more than 2 quadrants (PAC2). At the initial diagnosis, the mean age was 64.8±8.4, and the mean IOP was 15.7±3.8 mm Hg. There was a significant correlation between the maximum IOP before the LPI and the extent of the PAS (P=0.0002; Spearman rank correlation). After LPI, the success rate, that is, an IOP less than 20 mm Hg with medications at 2 consecutive visits, in the PACS group was 100% during a 10-year follow-up. The success rate was 89.8%±3.7% and 62.7%±16.6% in eyes with PAC1 and eyes with PAC2, respectively (P=0.0767, PAC2 versus PAC1; log-rank test). The majority of chronic PAC, at least, eyes with less extensive PAS, maintained good IOP control with and without antiglaucoma drugs, and the extent of preexisting organic angle closure was one of the predictive prognostic factors.