[Values and complications of peripheral deepenings in radial keratotomies]

Single and double peripheral deepenings were used to increase the refractive effect of radial keratotomy (RK). The objective of this study was to statistically evaluate the effect and the complications of these surgical techniques. Simple and double peripheral deepenings were performed in 36 patients (52 eyes) and 14 patients (19 eyes) respectively. The functional results and the complications in these two groups were statistically compared with those of a control group which was comparable according to criteria of size, age, sex and preoperative myopia. The standard RK surgical technique was used in this control group. The difference of mean gain between the control group, and the single and double peripheral deepening groups, was 0.53 and 0.47 diopter, respectively. This difference was statistically significant. On the other hand there was no significant difference diopter gain between the single and the double peripheral deepening groups. There was a significant difference concerning spherical equivalent. The non corrected visual acuity was significantly higher in the peripheral deepenings groups, probably due to corneal topographic alterations generating multifocal corneas. The complication rate (micro-perforations, induced astigmatism, loss of best corrected visual acuity) was higher in the peripheral deepenings groups. The limited diopter gain (about 0.50 diopter) compared with the standard radial keratotomy surgical technique, the lack of decreased, reoperation rate and the increased rate complication justified peripheral deepenings surgery technique discussed by the authors.