Purpose To assess the optimal number and orientation of anterior segment optical coherence tomography (AS-OCT) images for accurately measuring ocular biometric parameters in angle closure eyes. Methods Subjects with angle closure, defined as >3 quadrants of non-visible pigmented trabecular meshwork on static gonioscopy, were selected from the Chinese American Eye Study. Mean angle opening distance (AOD500) was calculated using four images (0°−180°, 45°−225°, 90°−270° and 135°−315° meridians) from one eye per subject. Ten eyes from each quartile of AOD500 measurements were randomly selected for detailed 32-image analysis of 10 biometric parameters, including AOD500, iris curvature (IC), anterior chamber depth (ACD), lens vault (LV), and anterior chamber area (ACA). Mean and range of measurements from 1, 2, 4, 8 or 16 images were compared with 32-image values for all parameters. Results 40 out of 335 eyes with angle closure were selected for 32-image analysis. Deviation from the 32-image mean was between 0.44% and 19.31% with one image, decreasing to 0.08% to 4.21% with two images for all parameters. Deviation from the 32-image range of measurements was between 54.67% to 88.94% with one image, decreasing to <7.00% with eight images for all parameters except ACD and ACA. Orienting the first image analysed along the 25°−205° meridian better approximated the range of measurements when four or fewer images were analysed. Conclusions Sectoral anatomical variations in angle closure eyes are easily misrepresented based on current AS-OCT imaging conventions. A revised multi-image approach can better capture the mean and range of biometric measurements. Data are available on reasonable request. Please direct inquiries to : benjamin.xu@med.usc.edu.

中文翻译：

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用于测量闭角眼眼部生物特征参数的眼前节 OCT 图像的最佳数量和方向：美国华人眼科研究

目的 评估用于准确测量闭角眼眼部生物参数的眼前节光学相干断层扫描 (AS-OCT) 图像的最佳数量和方向。方法 房角闭合的受试者，定义为静态房角镜检查中不可见色素小梁网的 > 3 个象限，选自美国华人眼科研究。使用每个受试者一只眼睛的四张图像（0°−180°、45°−225°、90°−270° 和 135°−315° 子午线）计算平均开角距离 (AOD500)。从 AOD500 测量的每个四分位数中随机选择十只眼睛，对 10 个生物参数进行详细的 32 幅图像分析，包括 AOD500、虹膜曲率 (IC)、前房深度 (ACD)、晶状体拱顶 (LV) 和前房面积 (ACA) ). 1、2、4 的测量平均值和范围，将 8 或 16 张图像与 32 张图像的所有参数值进行比较。结果 335 只闭角眼中的 40 只被选作 32 幅图像分析。对于所有参数，一张图像与 32 幅图像平均值的偏差在 0.44% 和 19.31% 之间，两幅图像的偏差降低到 0.08% 到 4.21%。一张图像与 32 张图像测量范围的偏差在 54.67% 到 88.94% 之间，八张图像的所有参数（ACD 和 ACA 除外）降低到 <7.00%。当分析四张或更少的图像时，将分析的第一张图像定向为沿 25°−205° 子午线可以更好地近似测量范围。结论 根据当前的 AS-OCT 成像惯例，闭角眼的扇形解剖变异很容易被误解。修订后的多图像方法可以更好地捕捉生物测量的平均值和范围。可应合理要求提供数据。请直接查询：benjamin.xu@med.usc.edu。