Orbscan角膜地形图鉴别早期圆锥角膜的敏感指标研究  

Obscan II topography sensitive indices to aid in screening for early keratoconus

作　　者：姚勇[1] 刘祖国[1] 张梅[1] 陈龙山[1] 钟兴武[1] 王智崇[1] 黄挺[1] 杨浩江[1] 陈家祺[1] 

机构地区：[1]中山大学中山眼科中心眼表疾病研究中心,广州昆明眼科医院510060

出　　处：《中国实用眼科杂志》2006年第11期1162-1166,共5页Chinese Journal of Practical Ophthalmology

基　　金：国家科技攻关计划(2004BA720A15)

摘　　要：目的了解早期圆锥角膜的地形图特点,寻找诊断早期圆锥角膜的敏感地形图指标。方法前瞻性应用OrbscanⅡ研究评价37例临床早期圆锥角膜患者、62例中高度近视(以下简称近视组)和43例中高度近视角膜接触镜佩戴者(以下简称接触镜组),了解早期圆锥角膜角膜地形图的参数改变特点,并进行判别分析。结果早期圆锥角膜组和近视组及接触镜组比较,年龄、近视度数、散光度数均无统计学差异(均P>0.05)。角膜地形图参数中,Im-Sm值、I-S值、中央角膜曲率、角膜最薄点厚度、角膜前表面高度、角膜后表面高度、模拟散光度数(SimK'sAstig)、最大模拟曲率(SimK'sMax)、3.0mm区不规则性(3.0mmZoneIrreg)、3.0mm区平均度数(3.0mmZoneMeanPwr)、3.0mm区散光度数(3.0mmZoneAstigPwr)、5.0mm区不规则性(5.0mmZoneIrreg)等在早期圆锥角膜与近视组及接触镜组之间均有统计学差异(均P<0.05);角膜厚度指数(CTI)、5.0mm区平均度数(5.0MMZoneMeanPwr)、5.0mm区散光度数(5.0MMZoneAstigPwr)在早期圆锥角膜与对照组之间没有统计学差异(均P>0.05)。判别分析显示Im-Sm、中央角膜曲率、角膜最薄点厚度(Thinnestcornealthickness)、3.0mmZoneIrreg、3.0mmZoneAstigPwr均是诊断早期圆锥角膜的敏感指标。典则判别函数为:D=-6.560+0.274X1+0.177X2-0.005X3+0.182X4+0.224X5(X1=Im-Sm;X2=中央角膜曲率;X3=角膜最薄点厚度;X4=3.0mmZoneIrreg;X5=3.0mmZoneAstigPwr),判别符合率为90.1%。结论Im-Sm、中央角膜曲率、角膜最薄点厚度、3.0mmZoneIrreg、3.0mmZoneAstigPwr等参数有助于区分早期圆锥角膜和中高度近视/角膜接触镜佩戴者,是诊断早期圆锥角膜的敏感地形图指标。Objective To evaluate the characteristic and search the sensitive index for diagnosis of early keratoconus in corneal topography. Methods A prospective study using Orbscan was performed in early keratoconus, media / high myopia with/without a history of corneal contact lens of similar age and diopter as control. We evaluated the results and carried out discriminant analysis. Results In this study, there is no statistically significance among the three groups in ages, degree of myopia and astigmatism （all P 〉0.05）.we discover that there are statistically significance in the Im-Sm. I-S . central keratometry , the thinnest thickness of cornea, anterior elevation, posterior elevation, SimK＇s Astig , SimK＇s Max, 3.0mm Zone Irreg. 3.0mm Zone Mean Pwr. 3.0mm Zone Astig Pwr and 5.0mm Zone Irreg between the early keratoconus and control （all P〈0.05）. There are not statistically significance in the CTI. 5.0mm Zone Mean Pwr and 5.0mm Zone Astig Pwr between the early keratoconus and control （all P〉0.05）.The Im-Sm, central corneal keratometry, Thinnest corneal thickness,3.0mm Zone Irreg and 3.0mm Zone Astig PWr are sensitive index in the diagnosis of early keratoconus according to discriminant analysis. Canonical discriminant function formula are as follow：D=-6.560＋0.274X1＋0.177X2-0.005X3＋0.182X4＋0.224X5 （X1= Im-Sm; X2= central keratometry; X3=thinnest corneal thickness ; X4=3.0mm Zone Irreg; X5=3.0mm Zone Astig Pwr）.We got the discriminant rate of 90.1%. Conclusions All Im-Sm, central keratometry, thinnest corneal thickness,3.0mm Zone Irreg and 3.0mm Zone Astig PWr appear to be sensitive and specific for diagnosing early keratoconus. These indices may prove to be clinically useful parameters for distinguishing early keratoconus from myopia with / without a history of corneal contact lens.

关 键 词：角膜地形图 圆锥角膜 诊断 

分 类 号：R778.11[医药卫生—眼科]