Background/aims To identify ocular determinants of iridolenticular contact area (ILCA), a recently introduced swept-source optical coherence tomography (SSOCT) derived parameter, and assess the association between ILCA and angle closure. Methods In this population-based cross-sectional study, right eyes of 464 subjects underwent SSOCT (SS-1000, CASIA, Tomey Corporation, Nagoya, Japan) imaging in the dark. Eight out of 128 cross-sectional images (evenly spaced 22.5° apart) were selected for analysis. Matlab (Matworks, Massachusetts, USA) was used to measure ILCA, defined as the circumferential extent of contact area between the pigmented iris epithelium and anterior lens surface. Gonioscopic angle closure (GAC) was defined as non-visibility of the posterior trabecular meshwork in two or more angle quadrants. Results The mean age of subjects was 62±6.6 years, with the majority being female (65.5%). 143/464 subjects (28.6%) had GAC. In multivariable linear regression analysis, ILCA was significantly associated with anterior chamber width (β=1.03, p=0.003), pupillary diameter (β=−1.9, p<0.001) and iris curvature (β=−17.35, p<0.001). ILCA was smaller in eyes with GAC compared with those with open angles (4.28±1.6 mm2 vs 6.02±2.71 mm2, p<0.001). ILCA was independently associated with GAC (β=−0.03, p<0.001), iridotrabecular contact index (β=−6.82, p<0.001) or angle opening distance (β=0.02, p<0.001) after adjusting for covariates. The diagnostic performance of ILCA for detecting GAC was acceptable (AUC=0.69). Conclusions ILCA is a significant predictor of angle closure independent of other biometric factors and may reflect unique anatomical information associated with pupillary block. ILCA represents a novel biometric risk factor in eyes with angle closure. Data are available on reasonable request.

中文翻译：

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研究虹膜晶状体接触面积的决定因素：角度闭合的新参数


背景/目的 确定虹膜晶状体接触面积 (ILCA)（最近推出的扫源光学相干断层扫描 (SSOCT) 衍生参数）的眼部决定因素，并评估 ILCA 与闭角之间的关联。方法 在这项基于人群的横断面研究中，464 名受试者的右眼在黑暗中接受了 SSOCT（SS-1000，CASIA，Tomey Corporation，名古屋，日本）成像。从 128 个横截面图像（均匀间隔 22.5°）中选择 8 个进行分析。 Matlab（Matworks，马萨诸塞州，美国）用于测量 ILCA，定义为色素虹膜上皮和晶状体前表面之间接触区域的圆周范围。房角镜闭角（GAC）被定义为两个或多个角象限中后小梁网不可见。结果 受试者的平均年龄为62±6.6岁，其中大多数为女性（65.5%）。 143/464 名受试者 (28.6%) 患有 GAC。在多变量线性回归分析中，ILCA与前房宽度（β=1.03，p=0.003）、瞳孔直径（β=-1.9，p<0.001）和虹膜曲率（β=-17.35，p<0.001）显着相关。与开角眼相比，GAC 眼的 ILCA 更小（4.28±1.6 mm2 vs 6.02±2.71 mm2，p<0.001）。调整协变量后，ILCA 与 GAC（β=-0.03，p<0.001）、虹膜小梁接触指数（β=-6.82，p<0.001）或角度张开距离（β=0.02，p<0.001）独立相关。 ILCA 检测 GAC 的诊断性能是可以接受的（AUC=0.69）。结论 ILCA 是独立于其他生物特征因素的闭角的重要预测因子，并且可以反映与瞳孔阻滞相关的独特解剖信息。 ILCA 代表了闭角眼的一种新的生物识别风险因素。 可根据合理要求提供数据。