Repeated radial keratotomy in the prospective evaluation of radial keratotomy study.

In the Prospective Evaluation of Radial Keratotomy study, 59 patients received a repeated radial keratotomy in which the eight additional incisions were centered between the eight initial incisions. Other aspects of the surgical technique remained the same. The average length of follow-up after the reoperation was 26 months, and ranged from 11 to 42 months. After the reoperation, 45 patients (77%) had a decrease in myopia of 0.50 diopters or more, 12 patients (20%) changed by less than 0.50 diopters, and two patients (3%) had an increase in myopia. Thirty patients (51%) remained undercorrected by more than 1.00 diopter, 27 patients (46%) were between +0.12 and -1.00 diopter, and two patients (3%) were overcorrected by more than 1.00 diopter. There was no relationship between the change in refractive error after the reoperation and any patient characteristics or surgical factors. After the reoperation, the uncorrected visual acuity increased by two to nine Snellen lines for 45 patients (76%), changed one line or less for 13 patients (22%), and decreased three lines for one patient (2%).