[Stability of refraction in post-operative two years of radial keratotomy]

In order to study the stability of the refraction after radial keratotomy, we took 123 cases (245) eyes who all had continuous follow-up records in two postoperative years to observe their dynamic changes. The mean preoperative spherical equivalent refraction was -6.74 D, and the mean keratometry was 44.32 D. The mean spherical equivalent refraction which was reduced after the surgery at one week, one month, three months, six months, one year and two years was 6.77 D, 5.74 D, 5.14 D, 5.09 D, 5.14 D and 5.27 D, respectively. The decrease of the spherical equivalent refraction in our cases showed that the maximum range of myopic drop was at one week after surgery. But the myopia obviously rose again in the postoperative three months. Statistical analyses showed that the differences between one week and one month and between one week and three months after surgery were significant (P < 0.01). There were little changes in the course of postoperative six months to two years, being not significant statistically (P > 0.05).