方法：纳入我院早期圆锥角膜患者88例93眼，依据相关标准，将其分为临床期圆锥角膜组(43例46眼)、亚临床期圆锥角膜组(45例47眼)，另选择同期有近视、散光史(散光≥2.0D)的患者(40例41眼)记为对照组，经Pentacam眼前节分析仪测定三组圆锥角膜指数(KI)、角膜表面变异系数(ISV)、垂直不对称指数(IVA)等，分析各指标对圆锥角膜的诊断价值。

结果：三组的Pentacam眼前节分析仪各参数均有差异(P<0.05)，对照组Rmin最高，其他参数最低，临床期圆锥角膜组Rmin较亚临床期圆锥角膜组低，而其他参数均高于亚临床期圆锥角膜组(P<0.05)； KI、ISV、IVA及高度离心指数(IHD)、不规则指数(ABR)、角膜前表面最大屈光力(Kmax)、角膜后表面高度(PE)、最小曲率半径(Rmin)、角膜前表面高度(AE)诊断临床期圆锥角膜的曲线下面积(AUC)分别为1、1、1、1、0.950、0.919、0.951、1、0.992，有较好敏感度、特异度，诊断亚临床期圆锥角膜时IVA、Rmin、AE、PE有较好敏感度、特异度，其AUC分别为0.927、0.923、0.954、0.947。

结论：Pentacam眼前节分析系统在圆锥角膜的早期诊断中有重要价值。

METHODS:Totally 88 patients(93 eyes)with early keratoconus were divided into clinical keratoconus group(43 cases, 46 eyes)and subclinical keratoconus group(45 cases, 47 eyes)according to related standards. Meanwhile, 40 patients(41 eyes)with history of myopia and astigmatism(astigmatism ≥2.0D)were recorded as the control group. The keratoconus index(KI), corneal index of surface variance(ISV)and index of vertical asymmetry(IVA)were determined using Pentacam anterior segment analyzer, and their diagnostic value for keratoconus was analyzed.

RESULTS:The parameters of Pentacam anterior segment analyzer were different among the three groups(P<0.05). Rmin was the highest, and other parameters were the lowest in the control group. Rmin was lower, and other parameters were higher in the clinical keratoconus group than in the subclinical keratoconus group(P<0.05). The area under curve(AUC)values of ISV, KI, IVA, index of highest decentration(IHD), aberration coefficient(ABR), corneal anterior surface maximum keratometry(Kmax), posterior corneal surface elevation(PE), minimun radius of curvature(Rmin)and corneal anterior surface elevation(AE)in the diagnosis of clinical keratoconus were 1, 1, 1, 1, 0.950, 0.919, 0.951, 1 and 0.992, with good sensitivity and specificity. IVA, Rmin, AE, and PE had better sensitivity and specificity in the diagnosis of subclinical keratoconus. The AUC values were 0.927, 0.923, 0.954, and 0.947, respectively.

CONCLUSION:Pentacam anterior segment analysis system has great value in early diagnosis of keratoconus.