近视人群双眼角膜参数的差异

摘要

Objective To compare the corneal parameters of the two eyes in a myopia population and to establish the normal range of interocular differences for clinical examination and diagnosis.Methods In this cross-sectional study,210 patients (420 eyes) whose mean age was 24.8±0.4 years,average spherical equivalents were-4.96±0.14 D in right eyes and-4.94±0.14 D in left eyes,were measured by Pentacam.Corneal parameters,including mean keratometry Km,central corneal thickness (CCT),thinnest corneal thickness (TCT),the location of the thinnest points (X,Y) and the distance from the thinnest to central corneal points （√(X2+Y2）) and the interocular differences were recorded.A paired t test was used to assess the differences between the two eyes' corneal parameters and a Pearson correlation was used to describe their linear relationship.The normal range of interocular differences was described by the 95th percentile or mean+2 standard deviation (SD).Results No statistically significant binocular differences were found in Km (t=-1.38,P＞0.05),CCT (t=1.44,P＞0.05),TCT (t=1.25,P＞O.05),√（X2+Y2）(t=1.87,P＞0.05) except X (t=-33.92,P＜0.01) and Y (t=8.95,P＜0.O1).Less than 5％ of the sample had differences greater than 0.5 D in Km,13.67 μm in CCT,12.83 μm in TCT,1.52 mm in the vertical location of the thinnest points,0.32 mm in the horizontal location of the thinnest points,or 0.30 mm in the distance from the thinnest to central corneal points between eyes.Conclusion Binocular corneal parameters have some differences.The normal range of binocular differences can provide a guide for intraocular lens power calculation,clinical diagnosis and screening of glaucoma and corneal ectasia disease.%目的 评估近视人群双眼角膜各参数的差异性,并计算差值的医学参考值范围,为临床实践提供依据.方法 横断面研究.210例近视患者(420眼),平均年龄为(24.8±0.4)岁,右眼等效球镜度为(-4.96±0.14)D,左眼等效球镜度为(-4.94±0.14)D.应用Pentacam眼前节全景仪进行测量,记录双眼平均角膜屈光力(Km),中央角膜厚度(CCT),最薄点角膜厚度(TCT),以顶点为中心的最薄点的水平坐标值(X)、垂直坐标值(Y),最薄点与顶点的距离(√(X2+Y2)).配对t检验评估双眼角膜各参数的差异;Pearson相关分析双眼角膜各参数的相关性;采用第95％分位数或均数加2倍的标准差((x)+2s)描述双眼角膜各参数差值的医学参考值范围.结果 双眼角膜Km、CCT、TCT、最薄点与顶点的距离√(X2+Y2)差异均没有统计学意义(t=-1.38、1.44、1.25、1.87,P均＞0.05);双眼以顶点为中心的最薄点的水平坐标值(X)、垂直坐标值(Y)差异有统计学意义(t=-33.92、8.95,P均＜0.01).双眼角膜Km,CCT,TCT,以顶点为中心的最薄点的水平坐标值X、垂直坐标值Y,最薄点与顶点的距离√(X2+Y2)差值的95％医学参考值范围上限分别为0.5 D、13.67 μm、12.83 μm、1.52 mm、0.32 mm、0.30 mm.结论 Pentacam获得的近视人群双眼角膜各参数相近,但仍具有一定差异性,而这些角膜参数差值的医学参考值范围可能为眼科相关疾病(如青光眼、角膜扩张性疾病等)的诊断和筛查提供指导.