HISTOPATHOLOGIC COMPARISON OF CONVENTIONAL RADIAL KERATOTOMY AND MINIMALLY INVASIVE RADIAL KERATOTOMY IN RABBITS

The aim of the present study was to compare conventional radial kerato tomy (RK) with minimally invasive RK (mini-RK) in terms of achieved in cisional depth as well as the histopathologic changes in the rabbit co rneal structures. Four conventional RK incisions were performed on the right eye and four mini-RK incisions were performed on the left eye o f 12 Island rabbits using a centripetal cutting technique. The corneas were excised 20 days after the procedure and examined by light micros copy. Histopathologic examination showed that the mean achieved incisi onal depth (73.47%) in conventional RK was consistent with the intende d incisional depth (80%), However, the mean achieved incisional depth (47.28%) was far from the intended incisional depth (80%) in eyes rece iving mini-RK. The difference be tween achieved incisional depth of th e two surgical techniques was statistically significant (t = 10.70, P < 0.05). Corneal structural changes and epithelial plug formations wer e less in eyes in mini-RK than in conventional RK. These findings sugg ested that the refractive results in mini-RK may be less effective tha n conventional RK. On the other hand, in the mini-RK group, less epith elial plug formation and limited histopathologic structural alteration s may have an important role in preventing long-term overcorrection an d corneal rupture after ocular trauma demonstrated in conventional RK technique. (C) 1997 Japanese Ophthalmological Society.