应用超长扫描深度谱域OCT测量人眼角膜和巩膜弧矢高度及角巩膜缘形态

Measurements of corneal/scleral sagittal height and corneoscleral junction shape using ultra-long scan depth spectral domain optical coherence tomography

目的 使用超长扫描深度谱域OCT（UL-OCT）研究人眼的角膜和巩膜的弧矢高度和角巩膜缘的形态.方法 横断面研究.本研究共纳入40例被检者（80眼）,其中男17例,女23例,平均年龄（25.8±2.8）岁.UL-OCT分别拍摄被检者的双眼,应用自行编写的程序量化分析及使用配对t检验比较距离角膜中央各个位置垂直及水平子午线上的角膜及巩膜的弧矢高度,测量角巩膜缘参数并使用重复测量数据方差分析比较各象限参数值的差异.结果 被检者左右眼的同侧的角膜中央旁开1.5、3、5、7mm处的角膜或巩膜的弧矢高度以及角巩膜缘转折点的X、Y轴坐标和该点距离角膜中央3mm平均切向曲率的差异值之间的差异均无统计学意义.水平子午线上,除X轴坐标之外,其余参数在鼻侧和颞侧的差异均有统计学意义（P＜0.05）.垂直子午线上,所有参数在上侧和下侧的差异均无统计学意义.角巩膜缘的转折点的X轴坐标在垂直子午线上较水平子午线上更靠近角膜顶点,Y轴坐标在鼻侧离角膜顶点最远.转折点距离角膜中央3 mm平均切向曲率的差异值在鼻侧最大（P＜0.05）,其他3个位置之间差异没有统计学意义.结论 左右眼同侧的弧矢高度参数无明显差异.角巩膜缘在鼻侧较其他位置表现出更大的转折.

Objective To investigate corneoscleral dimensions and sagittal heights in the cornea and sclera using ultra-long scan depth spectral domain optical coherence tomography （UL-OCT）.Methods This was a cross-sectional investigation.Forty subjects （80 eyes,17 men,23 women; mean age,25.8±2.8 years） were recruited for the study.UL-OCT image acquisition was taken for each eye.Custom software was used to quantify corneal/scleral sagittal height and dimensions of the corneoscleral junction.The differences in sagittal heights and dimensions of the corneoscleral junction in the four quadrants were analyzed with a paired t test and repeated measures ANOVA.Results There were no significant differences in the X and Y axis coordinates in the corneoscleral junction,the tangential curvature difference between the corneoscleral junction and the mean tangential curvature of the central 3 mm cornea and the corneal/scleral sagittal height （chord distances of 1.5,3,5 and 7 mm from the corneal apex） in the same locations between the left and right eyes.Except for the X axis coordinates,other dimensions were larger on the nasal side than the temporal side （P＜0.05）.There were no significant differences among all dimensions between the superior and inferior sides at the vertical meridian.The values of the X axis coordinates at the vertical meridian were closer to the corneal apex than the horizontal meridian.The values of the Y axis coordinates and the tangential curvature difference between the corneoscleral junction and the mean tangential curvature of the central 3 mm cornea were largest on the nasal side compared to other locations （P＜0.05）.Conclusion There are no significant differences for any dimensions at the same location between the left and right eyes.The comeosclera presents a larger junction angle on the nasal side than at other locations.