[Wound healing of the cornea of New World monkeys after surface keratectomy: Er:YAG-excimer laser].

Corneal wound healing was studied after photoablation with an excimer laser (193 nm, 43 pulses at 180 mJ/cm2 [symbol: see text] 11 microns ablation depth, optical zone 2.0 mm) and with an erbium-YAG laser (2.94 microns, 5 pulses at 2.5 J/cm2 [symbol: see text] 50 microns ablation depth, optical zone 1.6 mm). The corneas of marmosets (Callithrix jacchus) were prepared 5 and 10 days and 4 and 25 weeks after photoablation. The sections were investigated by conventional light microscopy or exposed to antibodies against collagen types I, III, IV, VII and laminin and stained by indirect immunofluorescence. Macroscopically, the time-course of wound healing was comparable to that seen, after laser keratomileusis for correction of myopia in humans (epithelium closure after 24-48 h, subepithelial haze: erbium-YAG less than or equal to excimer). Histologically the time-course of wound healing could be schematically divided into three phases: (1) epithelial hyperplasia, inhomogeneous new synthesis of collagen fibrils subepithelially; (2) reorganization of the epithelium, hyperplasia of keratocytes, incipient reorganization of the collagen fibrils, increase in subepithelial haze; (3) reorganization of the collagen fibrils, decrease in subepithelial haze. The distribution of collagen type VII during the corneal wound healing suggests that the subepithelial haze observed during the healing process after laser keratomileusis for correction of myopia is based on the anchoring fibrils of the basement membrane.