近视眼角膜厚度及相关因素分析

Analysis of corneal thickness and related factors of myopia

目的:探讨青年近视患者角膜厚度分布特点及其相关因素。方法:选取青年近视患者200例(400眼),按屈光度不同分为4组,应用OrbscanⅡ眼前节分析系统对患者的角膜中央点、最薄点、后表面平均屈光度最大点,以及距中心1.5,2.5mm上方、下方、颞上、颞下、鼻上、鼻下、颞侧、鼻侧部位的角膜厚度及相应的前房深度、后表面高度、后表面曲率、前表面曲率进行测量。结果:角膜厚度呈中心薄周边厚分布,最薄点位于距中心2.5mm范围内(86%),角膜颞下部位(50%)。后表面平均屈光度最大点、最薄点、中央点三个点的角膜厚度在不同近视组中差异无统计学意义(P>0.05)。不同部位的角膜厚度与其他因素相关分析。结果:中央点:角膜厚度与前房深度、前表面曲率负相关(r=-0.181,-0.103,P=0.000,0.039)。最薄点:角膜厚度与相应的前房深度、后表面高度、后表面曲率绝对值、前表面曲率呈负相关(r=-0.167,-0.113,-0.104,-0.109;P=0.001,0.024,0.038,0.03)。后表面屈光度最大点:角膜厚度与相应的前房深度、后表面高度、后表面曲率绝对值、前表面曲率呈负相关(r=-0.342,-0.138,-0.189,-0.159;P=0.000,0.000,0.000,0.001)。结论:角膜厚度最薄点多位于旁中心2.5mm颞下部位;角膜厚度与近视程度无关;角膜厚度与相应的前房深度、后表面高度、后表面曲率绝对值、前表面曲率为负相关关系。

AIM： To explore the corneal thickness and its correlative factors of myopic eyes in adults. METHODS： Two hundred myopic subjects （400 eyes） were recruited and divided into four groups according to the diopter. The Orbscan Ⅱ topography system was used to investigate corneal thickness, corresponding anterior chamber depth, posterior corneal surface height, posterior corneal surface curvature and anterior corneal surface curvature on these myopes. All the parameters were measured at the center, the thinnest point , posterior surface mean maximal refractive power point and at 1.5mm, 2.5mm from center of cornea for superior and inferior parts of cornea, supratemporal, inferotemporal, supranasal, inferonasal parts, temporal and nasal side. RESULTS： The average thickness of cornea was thinner at center than periphery. The thinnest point was mostly located at inferotemporal（50%） site within the area of 2.5mm（86%）from the center of cornea. At central point, thinnest point, posterior surface mean maximal refractive power point, there were no significant differences in corneal thickness among four groups （ P 〉 0. 05）. The analysis of correlations between the corneal thickness at different sites and its correlative factors showed：at central site： a negative correlation was found between corneal thickness and factors such as anterior chamber depth, anterior corneal surface curvature（ r= -0. 181 ,-0. 103, P= 0.000, 0. 039）; the thinnest point： a negative correlation was found between corneal thickness and factors such as corresponding anterior chamber depth, posterior corneal surface height, posterior corneal surface curvature（absolute value）, anterior corneal surface curvature （r=-0.167,-0.113,-0.104, -0.109;P= 0.001,0.024, 0.038, 0.03）; the posterior surface mean maximal refractive power point： a negative correlation was found between corneal thickness and factors such as correspon-ding anterior chamber depth, posterior corneal surface height, posterior corneal surface curvature （absolute value）, anterior corneal surface curvature（ r = -0.342,-0. 138,-0. 189,- 0.159; P= 0. 000 ,0. 000,0. 000,0. 001） . CONCLUSION： The thinnest point of cornea is mostly located at inferotemporal site within the area of 2.5mm from the center of cornea. At the center, the thinnest point, and the posterior surface mean maximal refractive power point, the corneal thickness was not related to the degree of myopia. The correlations between corneal thickness and anterior chamber depth, posterior corneal surface height, posterior corneal surface curvature absolute value）, anterior corneal surface curvature were negative.