准分子激光屈光性角膜切削术后角膜地形图的变化

The change in corneal topography after photorefractive keratectomy

目的探讨准分子激光屈光性角膜切削术（ＰＲＫ）后角膜表面形态和屈光力变化。方法ＴｏｍｅｙＴＭＳ２ＴＭ角膜地形图检查１２４只近视眼ＰＲＫ术前、术后１、６月和１年统计值的变化。结果ＰＲＫ术后眼绝对等级角膜地形图见梯度明显的蓝色低屈光带。ＳＲＩ和ＳＡＩ术后１月时比术前和术后６月、１年时高，ＩＡＩ术前后无变化。近视眼治疗等值球镜屈光度分别与ＳＲＩ、ＳＡＩ和ＩＡＩ的相关系数为０．７６６、０．４６１和－０．１０５。结论ＰＲＫ术后角膜屈光力稳定性较好，对角膜表面规则性和对称性早期有影响，逐渐恢复正常。ＰＲＫ角膜切削区带越多，对角膜表面形态影响越大。

ObjectiveTo investigate the change in corneal surface shapes and refractive powers after photorefractive keratectomy(PRK).Methods124 myopic eyes were examined with Tomey TMS 2 TM corneal topography before operation,and 1,6,or 2 mon after PRK.ResultsThe refractive powers after PRK were gradually decreased from periphery to central in absolute scales of corneal topography.SRI and SAI were increased at 1 mon after PRK,and had significant differences with those before operation,and 6,12 mon after PRK.IAI had no change before or after PRK.Correlation coefficients of spherical equivalent refraction with SRI,SAI,and IAI were 0.766,0.461 and -0.105.ConclusionThe stability of refractive powers after PRK was good.The corneal surface regularity and asymmetry showed some change at the early stage after PRK.The change in corneal surface shape was increased with more ablation of corneal surface.