[Radial keratotomy. Optical and functional results after a 5-year postoperative period]

The authors report a retrospective study of R.K. surgery performed on 72 eyes for simple myopia by one surgeon, five years after surgery. Fifty-four cases were observed regularly at 1 year and 5 years post-operatively, which allowed an analysis of refractive and visual parameters, for myopias between-1.5 and 6 D before surgery. Five years after: 92.9% of eyes were within +/- 1 D of emmetropia; 5.7% of eyes were undercorrected by more than 1 D; 1.4% of eyes were overcorrected by more than 1 D and 88.7% of the cases had uncorrected visual acuity of 20/40 or more. In general, our refractive and keratometric results were stable between the first and fifth year post-operatively. We report only one case of real undercorrection, and one case of progressive hyperopia with loss of best spectacle corrected visual acuity. In this study, we observed a statistically significant decrease of 1/100 in the mean uncorrected visual acuity, which is explained by remyopisations. All but one of them were less than 1 D. The review of long term results of R.K. is difficult because of the many different methodologies and protocols. However all of them show a unpredictable continuous increase in the effect of surgery in the hyperopia direction. Prolonged wound healing seems to be the most probable reason for this progressive hyperopia.