5‐Year progression of primary angle closure after treatment: the Primary Angle Closure Study (PACeS)

Abstract

AbstractPurposeThere is no recent evidence on progression rates of Primary Angle Closure (PAC) to Primary Angle Closure Glaucoma (PACG). We aimed to study the 5‐year progression rates of treated PAC to PACG or acute primary angle closure (APAC).MethodsA retrospective cohort study of 50 PAC subjects was performed. PAC was defined as iridotrabecular contact of 180 degrees or more, in the presence of raised intraocular pressure or peripheral anterior synechiae, without evidence of glaucomatous optic neuropathy. Data on intraocular pressure (IOP), gonioscopy, treatment instituted and time of progression to PACG or APAC were analyzed. In subjects with bilateral PAC, one eye per subject was randomly chosen for analysis.ResultsOf the 50 PAC subjects, 33 (66%) subjects were female, 49 (98%) subjects were of Chinese descent and 1 Indian. All 50 eyes were treated ‐ 48 underwent initial laser peripheral iridotomy (LPI) and 2 primary phacoemulsification. During the follow‐up period, 17 were started on IOP‐lowering medications, and 26 (52%) underwent cataract extraction. None of the eyes developed APAC. Only 2 eyes progressed to PACG over 5 years of follow‐up. None of the eyes underwent glaucoma filtration surgery. Both the eyes that progressed were not noted to have synechial angle closure on diagnosis, and progressed to PACG at 1 year and 2.5 years from time of PAC diagnosis respectively.ConclusionsThese results suggest that the risk of progression of treated PAC to PACG is low. Our findings reveal lower rates of 5‐year progression compared to previously published data.1The low progression rate could be related to the majority of subjects having had lens extraction.Reference Thomas, R., Parikh, R., Muliyil, J. and Kumar, R. S. Five‐year risk of progression of primary angle closure to primary angle closure glaucoma: a population‐based study. Acta Ophthalmologica Scandinavica 2003; 81: 480‐485