Anterior chamber angle biometry: quadrant variation, age change and sex difference

Purpose. To estimate the anterior chamber angle width (ACAW) in healthy volunteers quantitatively using an anterior eye segment analysis system and to clarify the involvement of aging and sex in ACAW. Methods. The ACAW of the upper, lower, medial, and lateral quadrants of 42 eyes from 42 healthy volunteers was measured by the NIDEK EAS-1000(R) anterior eye segment analysis system, a non-invasive in vitro measuring method based on Scheimpflug image analysis. Data from all subjects were employed to im estimate aging and quadrant differences; and age-matched male and female subjects were chosen from all subjects to study sex difference and aging. Results. Young subjects showed no significant inter-quadrant differences of ACAW. However. ACAW showed a significant negative correlation with age in all quadrants, but the lateral quadrant showed much mon narrowing than the others. The age-matched study revealed that ACAW narrowing was much greater in females than in males, and a polynomial regression analysis showed that this sex difference appeared in subjects older than middle age. Conclusions. The anterior eye segment analysis system revealed that ACAW decreased with age, especially in the lateral quadrant. The significantly more marked narrowness of ACAW in females older than middle age may be related to the high incidence of angle closure glaucoma in elderly females.