Anterior segment measurements and determinants of angle width with short, medium, and long axial lengths in a rural Chinese population

PURPOSE: To report the anterior segment measurements and investigate the determinants of angle width with short, medium, and long axial length (AL) in a rural Chinese population. DESIGN: Observational, population-based, cross-sectional study. METHODS: Subjects aged ≥35 years who underwent complete ocular examinations during the follow-up of the Handan Eye Study were included. Ocular data of the right eye were analyzed. Anterior segment parameters were obtained and stratified by age and sex. AL was categorized into short (<22.0 mm), medium (22.0–23.5 mm), and long (>23.5 mm) subgroups. Linear regression analyses were performed to identify the parameters associated with angle width (angle opening distance at 500 μm from the scleral spur (SS) [AOD500]). RESULTS: The final analysis included 4435 subjects (58.0 [49.0, 64.0] years old, 44.1% males). Smaller AOD500 was significantly associated with female sex (P = 0.032), larger iris thickness at 750 μm from the SS (IT750) (P < 0.001), larger lens vault (LV) (P < 0.001), and smaller anterior chamber volume (ACV) (P < 0.001) in the short AL subgroup; larger sphere equivalent (SE), IT750, iris curvature (IC), and LV and smaller ACV (all P < 0.001) in the medium AL subgroup; and larger SE, IT750, IA, IC, and LV and smaller ACV (all P < 0.001) in the long AL subgroup. CONCLUSIONS: Our study provides the anterior segment parameters of a large rural Chinese population. IT750, ACV, and LV were found to be the most important factors associated with angle width.