摘要目的 评价Sirius三维角膜地形图对于角膜屈光手术前疑似圆锥角膜的筛查作用.方法 回顾性系列病例研究.2016年1至9月于北京大学第三医院眼科近视屈光手术中心进行常规术前检查的连续屈光不正患者816例(1 632只眼).Sirius三维角膜地形图自动分类提示为疑似圆锥角膜的37例(59只眼)纳入疑似组,其中女性25例(40只眼),男性12例(19只眼),平均年龄(28.9±7.4)岁;Sirius三维角膜地形图提示双眼无异常者按病历编号选出前59例患者(59只眼)纳入对照组,其中女性38例(38只眼),男性21例(21只眼),平均年龄(27.1±6.4)岁.分析疑似组角膜前、后表面以及角膜最薄点厚度的情况,并与对照组进行比较;同时使用Pentacam角膜地形图仪进行验证.角膜最薄点厚度数据采用独立样本t检验,其他数据采用Mann-Whitney U检验.结果 疑似组前、后表面对称性指数及前、后表面圆锥角膜向量指数中位数分别为0.84、0.22、0.58、0.51 D,对照组分别为0.05、0.04、0.09、0.06D,差异均有统计学意义(Z=-18.764,-8.351,-12.248,-10.709;P＜0.01).疑似组和对照组平均ThkMin分别为(504.4±30.0)、(541.2±32.1)μm,差异有统计学意义(t=-6.408,P＜0.01).疑似组中,与角膜前表面指数疑似或异常相关的眼数占47.5％(28/59);与角膜后表面指数疑似或异常相关的眼数占55.9％ (33/59);与角膜最薄点厚度疑似或异常相关的眼数占40.7％ (24/59).疑似组Pentacam角膜地形图的Belin-Ambrósio增强膨隆显示中总体偏差指数D显示为疑似或异常的有45只眼(76.3％),其余14只眼至少有一项与筛选圆锥角膜相关的指数异常.结论 Sirius三维角膜地形图仪及其自动分类系统可以简便有效地筛查出疑似圆锥角膜,各指数敏感度从高至低依次为角膜后表面、角膜前表面、角膜最薄点厚度.

abstractsObjective To evaluate the role of Sirius combined topography and tomography system in screening for suspect keratoconus among the corneal refractive surgery candidates.Methods Retrospective case series study.Eight hundred and sixteen consecutive ametropic patients (1 632 eyes) who underwent routine examinations before corneal refractive surgery at Peking University Third Hospital from January 2016 to September 2016 were reviewed.All the cases were analyzed with Sirius combined topography and tomography system.Fifty-nine eyes of 37 patients,aged (28.9 ± 7.4) years,classified as suspect keratoconus by the system were enrolled in the suspect group,including 25 females (40 eyes) and 12 males (19 eyes).A random eye of the first 59 patients,aged (27.1±6.4)years,whose both eyes were classified as normal by Sirius system were enrolled in the control group,including 38 females and 21 males.The corneal anterior surface,posterior surface and minimum thickness data of the suspect group were analyzed and then compared with the control group.The classified results were further verified by Pentacam system.Independent-samples t test and Mann-Whitney U test were applied to analyze the normal distribution and non-normal distribution data respectively.Results The medians of anterior surface and posterior surface symmetry index and Baiocchi Calossi Versaci index of anterior surface and posterior surface of the suspect group were 0.84,0.22,0.58 and 0.51 D,and that of the control group were 0.05,0.04,0.09 and 0.06 D,and the differences were of statistical significance (Z=-18.764,-8.351,-12.248,-10.709,P＜0.01).Mean corneal minimum thickness data of the suspect group were (504.4±30.0)1μm,and that of the control group were (541.2 ±32.1)μm,the differences were of statistical significance (t=-6.408,P＜0.01).In the suspect group,the eyes related with suspect or abnormal corneal anterior indices accounted for 47.5％ (28/59),the eyes related with suspect or abnormal corneal posterior indices accounted for 55.9％ (33/59),and the eyes related with suspect or abnormal corneal minimum thickness accounted for 40.7％ (24/59).In the suspect group,45 eyes(76.3％)were classified as suspect or abnormal according to the overall variance index "D" by Belin-Ambrósio Display (BAD) of the Pentacam system,and the other 14 eyes exhibited at least one abnormal index related with keratoconus.Conclusions Sirius 3D combined topography and tomography and its integral automatic classification system is capable to screen out the suspect keratoconus simply and effectively.These indices maybe arranged in descending order in terms of the sensitivity as corneal posterior surface,followed by corneal anterior surface and then corneal thinnest point thickness.