目的:分析进行性圆锥角膜(KC)患者角膜交联(CXL)前后角膜地形图显示的角膜扩张面积(KEA),以确定KEA是否适合评估CXL的疗效。
方法:对2015年至2017年24例进展性KC患者的34只眼进行回顾性分析。角膜地形图中显示的K值大于47D的区域被标记并识别为KEA。角化术(K1、K2和Kmax),KEA,最薄角膜厚度(TCT),术前或术后3,6和12个月评估内皮细胞密度(ECD)。评估手术前后KEA的变化。KEA和其他参数的关系,包括Kmax和TCT,被分析。
结果:线性回归模型揭示了KEA,Kmax,模型CXL后K1和K2降低,y=0.9622-0.02408倍(P<0.05),y=0.9982-0.003469x(P<0.05),y=0.9977+-0.001347x(P<0.05),y=0.9992+-0.001779x(P<0.05)(y代表KEA,Kmax,K1或K2;x表示时间(月))。早期(3个月前)KEA显著下降(P<0.05);Kmax,K1、K2在早期无明显下降(P=0.09、0.19、0.32)。
结论:在描述CXL后角膜的形态变化方面,KEA比K值更敏感,尤其是在治疗后的早期。
OBJECTIVE: To analyze the keratectasia area (KEA) shown in corneal topography before and after corneal cross-linking (CXL) in patients with progressive keratoconus (KC) and figure out whether KEA is appropriate for evaluating the effect of CXL.
METHODS: A retrospective analysis was conducted in 34 eyes from 24 progressive KC patients who have underwent CXL from 2015 to 2017. Area with K-value more than 47D shown in the corneal topography was marked and identified as KEA. Keratometry (K1, K2, and Kmax), KEA, thinnest corneal thickness (TCT), and endothelial cell density (ECD) were evaluated preoperatively or at months 3, 6, and 12 postoperatively. The changes of KEA before and after operation were evaluated. The relation of KEA and other parameters, including Kmax and TCT, was analyzed.
RESULTS: Linear regression model revealed the KEA, Kmax, K1, and K2 decreased after CXL in model y = 0.9622 -0.02408 x (P<0.05), y = 0.9982 -0.003469 x(P<0.05), y = 0.9977 + -0.001347 x(P<0.05), y = 0.9992 + -0.001779 x(P<0.05) (y represents KEA, Kmax, K1, or K2; x represents time (month)). The KEA is significantly decreased in early stage (before month 3) (P<0.05); however, the Kmax, K1, and K2 have no significant decrease in early stage (P= 0.09, 0.19, 0.32).
CONCLUSIONS: The KEA is more sensitive than K-value in describing the morphological changes of cornea after CXL, especially in early stage after treatment.