Distribution of angle α and angle κ in a population with cataract in Shanghai

Purpose: To describe the distribution of angle α and angle κ in a population with cataract in Shanghai. Setting: Eye and Ear, Nose, Throat Hospital, Fudan University, Shanghai, China. Design: Hospital-based, cross-sectional study. Methods: Angle α, angle κ, and other ocular biometric parameters were determined by IOLMaster 700. The distributions of angle α and angle κ and their associations with systemic and ocular parameters were assessed. Results: This study included 15 127 eyes of 15 127 cataract patients. The mean angle α and angle κ values were 0.45 ± 0.21 mm and 0.30 ± 0.18 mm, respectively. Angle α and angle κ were both predominantly located temporal to the visual axis. A greater angle α or angle κ was associated with older age, lower corneal power, shorter white-to-white distance, and shallower anterior chamber depth (all P < .05). Angle α correlated positively with angle κ. With increasing axial length (AL), angle α gradually decreased in a nonlinear way and shifted to the nasal side of the visual axis, whereas angle κ decreased in eyes with AL less than 27.5 mm but increased again in eyes with longer AL. Conclusions: Angle α and angle κ, both predominantly located temporal to the visual axis, were influenced by multiple anterior segment parameters. As AL increased, the changes in angle α and angle κ were nonlinear, and their locations gradually shifted from the temporal to the nasal side of the visual axis.