眼前节光学相干断层扫描仪测量圆锥角膜患者角膜地形图参数的重复性

Repeatability of topographic parameters measured by anterior segment optical coherence tomography in patients with keratoconus

目的探讨CASIA SS-1000 OCT测量圆锥角膜患者角膜地形图参数的重复性。方法诊断试验研究。纳入河南省立眼科医院2019年1月至2022年3月圆锥角膜95例(120只眼), 根据分期及角膜垂直中央曲率(Ks)将其分为4个组:亚临床组, 轻度组(Ks<48.0 D), 中度组(Ks=48.0~54.9 D)及重度组(Ks>54.9 D)。每组各30只眼。选取无其他眼部疾病的角膜屈光术前候诊者30例(30只眼)为对照组, 通过CASIA SS-1000 OCT共测量19个参数来比较各组重复性的差异。结果亚临床组与对照组所有参数相比差异无统计学意义(公差指数, TI_(1)<0.31);轻度组与对照组相比, 发现模拟角膜水平中央曲率(Kf)、角膜平均曲率(Km)、3 mm范围内轴向屈光力的平均值(Accp), 角膜前表面Kf、Km, 角膜后表面Ks, 角膜整体Kf、Km, 角膜顶点厚度(ACT), 角膜最薄点厚度(TCT)参数间差异无统计学意义(TI_(2)<0.31);中度组与对照组相比, 发现角膜后表面Kf、TCT参数间差异无统计学意义(TI_(3)<0.31);在重度组中, 所有参数的重复性与对照组之间差异均有统计学意义(TI_(4)>0.31)。结论应用CASIA SS-1000 OCT在评价轻度及中度圆锥角膜患者中具有较好的重复性。

Objective To investigate the repeatability of corneal topographic parameters measured by CASIA SS-1000 OCT in patients with keratoconus.Methods This was a diagnostic trial study.From Jan.2019 to Mar.2022,120 eyes of 95 cases with keratoconus in Henan Provincial Eye Hospital were included.They were divided into 4 groups based on the stage and corneal steep keratometry(Ks):subclinical group,mild group(Ks<48.0 D),moderate group(Ks=48.0-54.9 D)and severe group(Ks>54.9 D),with 30 eyes in each group.Thirty eyes of 30 cases of candidates without other eye diseases before corneal refractive surgery were selected as control group.A total of 19 parameters were measured by CASIA SS-1000 OCT to compare differences in repeatability amomg groups.Results No difference in the all parameters between the subclinical group and the control group(Tolerance index,TI_(1)<0.31).All the parameters in the mild group were compared with those in the control group,and it was found that the simulated steep keratometry(Kf),mean keratometry(Km),the average value of axial power within 3 mm(Accp)in the mild group,anterior corneal surface Kf,Km,posterior corneal surface Ks,real cornea Kf,Km,apex corneal thickness(ACT),thinnest corneal thickness(TCT)parameters were not significantly different(TI_(2)<0.31).All the parameters in the moderate group were compared with those in the control group,and it was found that the difference in Kf and TCT parameters of the posterior corneal surface were not statistically significant(TI_(3)<0.31).In the severe group,the repeatability of all parameters was statistically different from those of the control group(TI_(4)>0.31).Conclusion Application of CASIA SS-1000 OCT has good repeatability in evaluating patients with mild to moderate keratoconus.