屈光参差性弱视的Orbscan Ⅱz角膜地形图研究

摘要

Background The characteristics of anisometropic amblyopia in ocular morphology are becoming a hot topic in amblyopia field.And the interocular difference in corneal parameters of anisometropic amblyopia is to be understood here.Corneal topography is a non-invasive method for in vivo corneal examination and applied in our study.Objective This study was to investigate the interocular difference of corneal topography in anisometropic amblyopic patients Methods This was a serial cases observation.Thirty anisometropic amblyopes were selected in Center for Optometry and Visual Science,People's Hospital of Guangxi Zhuang Autonomous Region.The patients were divided into amblyopic eye group and fellow eye group based on the best corrected distance visual acuity.Corneal topography was examined with Orbscan Ⅱ z,and corneal morphological parameters such as Diff values of the anterior and posterior corneal surface,Sim K 's astigmatism,Kmax,angle kappa and central corneal thickness (CCT) were measured.The interocular differences in these parameters were evaluated by paired t test,and the correlations in these parameters between the amblyopic eyes and the fellow eyes were analyzed by Pearson linear correlation and simple regression analysis.Results The Diff values of the anterior corneal surface were (0.011±0.006)mm and (0.011±0.017)mm,and those in the posterior corneal surface were (0.031 ±0.012)mm and (0.026 ±0.008)mm in the amblyopic eye group and the fellow eye group,respectively.In addition,Sim K's astigmatism were (1.8± 1.1)D and (1.1 ±0.6) D,JCC were (77±80) °and (100±80) °,J0 values were (-0.17±0.72) D and (0.02±0.41) D,J45 values were (-0.16±0.79) D and (0.13 ±0.48) D,CCT values were (551 ±37) μm and (551 ±31) μm,angle kappa values were (6.4± 1.4) ° and (4.9 ± 1.2) ° in the amblyopic eye group and the fellow eye group,respectively.Significant differences were found in the Diff values of the anterior and posterior corneal surface,Sim K's astigmatism and angle kappa between the two groups (t=-3.041,P=0.005 ;t=-4.317,P=0.000 ;t=-4.571,P=0.000).Pearson's linear correlation test demonstrated significant interocular positive correlations in parameters such as the anterior corneal surface Diff values (r =0.444),J0 (r =0.383),posterior Diff values (r =0.600),and Sim K 's astigmatism (r =0.479),and CCT (r =0.948,P＜0.05).The linear regression equation between the two groups was Y =-0.005 +1.392X (R2 =0.197,F=6.858,P=0.014) in the Diff values in the anterior corneal surface,Y =-0.013+0.421X (R2=0.360,F=15.761,P=0.000) in the Diff values in the posterior corneal surface,Y =0.616+0.27X (R2=0.230,F=8.348,P=0.007) in the Sim K's astigmatism,Y=0.060+0.219X (R2 =0.147,F=4.814,P=0.037) in theJo and Y=i08.289+0.804X (R2 =0.899,F=250.293,P=0.000) in CCT.Conclusions Corneal morphological interocular differences exist significantly in anisometropic amblyopic patients.%背景 屈光参差性弱视的眼部形态学特征已成为弱视研究的一个热点,而此类患者双眼间的角膜形态特点及其相互关系尚不明确.角膜地形图是角膜无创性活体检查的主要工具,有助于了解屈光参差性弱视患者双眼角膜的形态. 目的 探讨屈光参差性弱视患者双眼角膜的形态学特征. 方法 纳入在广西视光中心就诊的屈光参差性弱视患者30例,按最佳矫正视力(BCVA)结果分为弱视眼组和对侧眼组.使用Orbscan Ⅱz角膜地形图测量仪检测患者双眼角膜的形态学数据,包括角膜前表面Diff值、后表面Diff值、模拟K值、角膜最强屈光力子午线轴向(Kmax)、中央角膜厚度(CCT)、Kappa角等指标,并将所得数据分别归入弱视眼组和对侧眼组.采用配对t检验对弱视眼组与对侧眼组检测指标数据资料的差异进行比较,采用Pearson积矩线性相关分析法及一元线性回归法对2个组间各形态学指标的关系进行分析. 结果 弱视眼组的角膜前表面Diff值为(0.011±0.006)mm,后表面Diff值为(0.031±0.012) mm,模拟K值为(1.8±1.1)D,JCC轴向为(77±80)°,J0为(-0.17±0.72)D,J45为(-0.16±0.79)D,CCT为(551±37)μm,Kappa角为(6.4±1.4)°；而对侧眼组的角膜前表面Diff值为(0.011±0.017)mm,后表面Diff值为(0.026±0.008) mm,模拟K值为(1.1±0.6)D,JCC轴向为(100±80)°,J0为(0.02±0.41)D,J45为(0.13±0.48)D,CCT为(551±31)μm,Kappa角为(4.9±1.2)°.两组间的角膜后表面Diff值、模拟K值和Kappa角的差异均有统计学意义(t=-3.041,P=0.005;t=-4.317,P=0.000;t=-4.571,P=0.000).两组间的角膜前表面Diff值(r=0.444)和J0值(r=0.383)呈微弱正相关,后表面Diff值(r=0.600)和模拟K值(r=0.479)呈中度正相关,CCT值均呈明显正相关(r=0.948,P＜0.05).线性回归分析显示,弱视眼与对侧眼间角膜前表面Diff值的回归方程为Y=-0.005+1.392X(R2=0.197,F=6.858,P=0.014),后表面Diff值的回归方程为Y=-0.013+0.421x (R2 =0.360,F=15.761,P=0.000),模拟K值的回归方程为Y=0.616+0.27X(R2 =0.230,F=8.348,P=0.007),J0的回归方程为Y=0.060+0.219X(R2 =0.147,F=4.814,P=0.037),CCT的回归方程为Y=108.289+0.804X(R2=0.899,F=250.293,P=0.000).结论 屈光参差性弱视患者的弱视眼与对侧眼在角膜形态学参数上存在明显差异.