MITOMYCIN-C REDUCES SCAR FORMATION AFTER EXCIMER-LASER (193 NM) PHOTOREFRACTIVE KERATECTOMY IN RABBITS

Sixteen eyes of eight rabbits were randomised to either mitomycin C or Balanced Salt Solution (BSS) application after photorefractive kerate ctomy (PRK). Regular examinations of wound healing and haze were perfo rmed with the slit lamp. The animals were killed between 1 and 26 week s after treatment, and the corneas examined by light and electron micr oscopy. While the grade of haze showed no relevant differences between the two groups, scar tissue was found histologically in the mitomycin group in only 1 of 8 corneas compared with 5 of 8 in the BSS group. A marked reduction in keratocytes in all mitomycin-treated corneas and a normal density of keratocytes in the BSS group was observed. Mitomyc in reduced the number of keratocytes in the treated corneas, leading t o less scar formation but not to a reduction in haze. Since no morphol ogical correlate has been found, haze remains unexplained in the mitom ycin-treated corneas.