Development of angle closure and associated risk factors: The Handan eye study

Purpose To investigate the development of angle closure from baseline open angle and associated risk factors in a rural Chinese population through a longitudinal study over a 5-year period. Methods Subjects aged >= 30 years and older with bilateral open angles at baseline of the Handan Eye Study who participated in the follow-up and had undergone both baseline and follow-up gonioscopic examinations were included. Subjects with any form of angle closure, glaucoma, incisional ocular surgery or other conditions that could influence the results were excluded. The development of angle closure was defined as the presence of primary angle closure suspect (PACS) or primary angle closure (PAC)/primary angle closure glaucoma (PACG) during the follow-up in normal subjects with baseline bilateral open angles. Logistic regression was performed to identify the baseline risk factors for the development of angle closure. Results A total of 457 subjects with bilateral open angles at baseline aged 53.0 (45.5, 58.0) years were enrolled. 94.7% of the included cases developed PACS, 5.3% developed PAC and no one developed PACG after 5 years. In logistic regression, significant risk factors for the development of angle closure were shallower central anterior chamber depth (ACD) (p = 0.002) and narrower mean angle width (p < 0.001). Conclusions This study reports the development from baseline open angle to angle closure after a 5-year follow-up. We confirm that the mean angle width and central ACD were independent predictive risk factors for the development of any form of angle closure.