准分子激光屈光性角膜切削术的角膜地形图分析

目的 分析准分子激光屈光性角膜切主后角膜地形图的变化和动态。方法 对接受准分子激光屈光性角膜切削术后随诊３个月的６２例（１２２只眼）和随诊６个月的４９例（９６只眼）的角膜地形图变化和动态进行分析。结果 中央岛型切削是导致术事早期最佳戴镜矫正视力下降１行以上的重要因素，随着时间推移，中央岛型切削逐渐演变其它类型，角膜中央曲率减爱，视力逐步提高。角膜地形图分析，拟似回退指数（ＳｉｍＫ）是反映角膜基质变

Corneal topographic analysis after excimer laser photorefractive keratectomy

Objective To analyze the changes in corneal topography after excimer laser photorefractive keratectomy (PRK). Methods The topographic changes of 122 eyes (62 patients) and 96 eyes (49 patients) on which PRK was performed were reviewed after 3 and 6 months of follow up respectively. Results The central island pattern had a relationship with the loss of best corrected visual acuity of more than one line in early postoperative period. On subsequent follow up, the central island pattern tended to become to other patterns (semicircular, keyhole and uniform) and the central corneal power decreased, allowing the visual acuity to improve gradually. The simulated K (Sim K) regression index was a useful indication of the changes in the corneal stroma. Sim K was related to the degree of refractive error. The greater the refractive error, the lower the Sim K. Conclusion Corneal topography is a useful tool in the analysis of corneal changes in PRK.