Increased lens vault as a risk factor for angle closure: confirmation in a Japanese population

Abstract

Purpose: A thicker lens vault (LV), measured by anterior segment optical coherence tomography (ASOCT), was recently identified as a novel risk factor for angle closure in Chinese Singaporeans. The purpose of our study was to investigate the association of LV with angle closure in Japanese subjects.

Design: Case-control study

Methods: One hundred and twenty-four subjects with primary angle-closure disease and 80 controls were recruited. All participants underwent ASOCT, and customized software was used to measure LV, defined as the perpendicular distance between the anterior pole of the lens and a horizontal line joining the two scleral spurs. A-scan biometry was used to measure lens thickness (LT) and to calculate lens position (LP) and relative lens position (RLP).

Results: Eyes with angle closure had significantly shallower anterior chamber depth (ACD), shorter axial length, greater LV and LT (p <0.001 for all), and anteriorly positioned lenses (LP, p < 0.001; RLP, p = 0.019). After multivariate analysis adjusted for age, gender, ACD, LT, and RLP, increased LV was significantly associated with angle closure (odds ratio [OR] 24.2; 95 % confidence interval [CI], 2.3-250.5, comparing lowest with highest quartile), but no association was found for LT (OR 2.59; 95 %CI, 0.48-13.85). In a sub-analysis evaluating the effect of LT on LV, LV was significantly greater in both the angle-closure group with thinner lens (LT ≤ 4.91 mm) and angle-closure group with thicker lens (LT > 4.91 mm) compared to normal controls (p < 0.001 for both).

Conclusions: In Japanese eyes, LV was independently associated with angle closure. These results corroborate the recent findings from Singapore on LV as a risk factor for angle closure.