Ultrasound Biomicroscopic Evaluation of Uveal Effusion in Acute Primary Angle Closure

Abstract

The aim of this study was to determine the prevalence of uveal effusion in acute primary angle closure (APAC), chronic primary angle-closure glaucoma (PACG), and primary open-angle glaucoma (POAG).A total of 152 consecutive patients (287 eyes) with APAC, PACG, and POAG were enrolled in this prospective and observational case series study. Intraocular pressure-lowering medications were used and ultrasound biomicroscopy examination was undertaken to determine the presence of uveal effusion and measure anterior chamber parameters.Overall, uveal effusion was evident in 40 of 194 affected eyes (20.6%) and no uveal effusion was seen in their fellow eyes. The prevalence of uveal effusion in APAC, chronic PACG, and POAG was 29.3%, 10.9%, and 3.1%, respectively (χ=226.63, P<0.001). APAC eyes had the highest prevalence of effusion and no effusion in their fellow eyes. In 40 eyes with uveal effusion, grade 1 effusion was seen in 17 eyes (42.5%), grade 2 in 15 eyes (37.5%), and grade 3 in 8 eyes (20%). In APAC eyes, the difference in the mean anterior chamber depth (ACD) among effusion grades 3, 2, and 1 was significant (F=5.425, P=0.017), and the eyes with grade 3 effusion had shallower ACD compared with grade 1 (P=0.031), but the difference was not significant compared with grade 2 (P=0.368).The eyes with APAC are associated with a higher prevalence of uveal effusion compared with PACG and POAG and probably as a result of rapid reduction in intraocular pressure with aggressive hypotensive therapy and inflammatory response to the process of acute attack.