摘要：
目的 分析高度近视并发白内障患者角膜后表面散光(PCA)及像差特征. 方法 采用回顾性研究设计.收集2014年9-12月复旦大学附属眼耳鼻喉科医院收治的白内障患者190例282眼,按眼轴长度(AL)分为高度近视组(AL≥26 mm)139眼和对照组(AL为20 ～ 25 mm)143眼.使用Pentacam测量角膜前后表面参数,包括平均角膜屈光力、中央角膜厚度、散光、像差等,并用IOL Master测量AL. 结果 高度近视组PCA值约为0.3 D(0～0.9 D),其中92.8％的散光值≤0.5D,以逆规散光(ATR)为主,占87.1％.高度近视组PCA值与对照组比较,差异无统计学意义(P=0.797).高度近视组PCA值与角膜前表面散光(ACA)、角膜前表面像差、角膜前表面低阶像差、角膜后表面像差、角膜后表面高阶像差、角膜后表面低阶像差均呈正相关(r=0.235,P=0.005;r=0.217,P=0.010;r=0.229,P=0.007;r=0.395,P=0.000;r=0.243,P=0.004;r=0.384,P=0.000).以ACA估计总角膜散光(TCA),在前表面为顺规散光(WTR)时对65.67％的患眼高估(0.27±0.18)D,ATR时对88.10％的患眼低估(0.41±0.30)D,斜轴散光(Obl)时对63.33％的患眼低估(0.22±0.10)D.以角膜前表面像差值估计角膜总像差时,会对87.05％的患眼高估(0.275±0.176) μm,ACA类型对其无影响. 结论 高度近视眼中92.8％的PCA≤0.5D,以ATR为主.白内障术前选择人工晶状体(IOL)时,应该将PCA和像差值纳入考虑范围.%Objective This study was to investigate the characteristics of posterior corneal astigmatism (PCA) and aberration in cataract patients with high myopia.Methods A retrospective study was designed.Two hundred and eighty-two eligible eyes of 190 cataract patients were enrolled in Eye and ENT Hospital of Fudan University from September to December,2014.The eyes were classified into two groups according to axial length (AL):high myopia group with 139 eyes (AL≥26 mm) and control group with 143 eyes (AL was 20 to 25 mm).The mean keratometric mid-radius of curvature (Km),corneal central thickness (CCT),astigmatism and aberrations were measured by the rotating Scheimpflug System (Pentacam),and the AL were measured by the partial coherence interferometry (IOL Master).This study followed the Helsinki declaration,and was approved by the Ethic Committee of Eye and ENT Hospital,Fudan University.Informed consent was signed from each patient.Results In high myopia group,the mean PCA was 0.3 D (range 0 ～ 0.9 D) and 92.8％ eyes had PCA values ＜0.5 D.The steep corneal meridian was aligned vertically (60°～ 120°) in 87.1％ eyes for the posterior corneal surface.There was no significant difference in PCA between the high myopia group and the control group (P =0.797).Significant positive linear correlations was found between PCA and anterior corneal astigmatism (ACA),PCA and anterior corneal root mean square (RMS),PCA and anterior lower-order RMS,PCA and posterior corneal RMS,PCA and posterior high-order RMS,PCA and posterior lower-order RMS (r =0.235,P =0.005;r =0.217,P =0.010;r =0.229,P =0.007;r =0.395,P =0.000;r =0.243,P =0.004;r =0.384,P =0.000).Compared with total corneal astigmatism (TCA),anterior corneal measurements overestimated with-the-rule astigmatism (WTR) by a mean of (0.27 ± 0.18) D in 65.67％ eyes,underestimated against-the-rule astigmatism (ATR) by (0.27 ± 0.18) D in 88.10％ eyes and underestimated oblique astigmatism (Obl) by (0.22 ± 0.10) D in 63.33％ eyes.Compared with total corneal aberrations,anterior corneal aberrations measurements overestimated by (0.275 ±0.176) μm in 87.05 ％ eyes,and the anterior corneal astigmatism types had no effect on the result.Conclusions In high myopia group,92.8％ eyes had PCA values ＜0.5 D and the main astigmatism type in posterior corneal surface was ATR.The posterior corneal astigmatism and aberration were needed to consider in choosing intraocular lens (IOL) before cataract surgery.
