1. Radial Keratotomy were performed on 104 cases (206eyes ) of myopia and follewed up for 2 yare.

2. Radial keratotomy without T-cutting was performed on 245 eyes of 124 patients with 6-8 months of post-operative follow-up.

3. Objective:To evaluate the predictability, stability and safety of excimer laser photorefractive keratectomy (PRK) for correcting the residual myopia and astigmatism after keratotomy (RK).

4. These patients underwent a standard eight - incision radial keratotomy procedure.

5. ObjectiveTo explore the effectiveness and safety of excimer laser photorefractive keratectomy(PRK) for correction of residual myopia after radial keratotomy(RK).

6. Stepwise regression analysis was used to build mathematical model of radial keratotomy(RK), for analyzing factors influencing on the result, and predicting the RK result.

7. This paper describes an excimer laser and its beam delivery system for corneal radial keratotomy.

8. In general, for correcting nearsightedness over 3 diopters, both LASIK and PRK are better than radial keratotomy (RK).