[Epithelial complications of sub-flap intrastromal photo-kerato ablation for correction of ametropia: causes, therapy, prophylaxis].

The causes of epithelial complications are evaluated from clinical viewpoint and approaches to their elimination in laser operations are developed. The study included analysis of 3227 intrastromal ablation operations performed by the LASIK and REIK methods in 1725 patients with myopia (spheroequivalent -6.47 +/- 2.23 diopters) and hypermetropia (spheroequivalent +4.57 +/- 1.88 diopters). Laser keratoablation was carried out on an EC 5000 device (Nidek, Japan). Lamellar keratomileusis was carried out with a Hansatome Chiron Vision 230 HT-TM microkeratotome (USA). The incidence of epithelial complications was 5.2%. Intraoperative complications occurred in 3.2% cases. Corneal erosions of 1 x 3 mm were responsible for 51.2% complications, extensive erosions for 18.4%, horizontal ruptures of the epithelium for 22.4%, and stretching of epithelial plast for 9.8% complications. Other complications were epitheliopathy (6 cases), growth of epithelium under corneal flap (0.7%), and "dry islets" in the epithelium (22%). The probable causes of epithelial complications were microkeratotome design, toxic effects of anesthetics, congenital desmosomopathy, and insufficient adaptation of corneal flap. Prevention of complications should consist in additional protection of the epithelium before and after the operation. The protection can be realized by using low-toxic antibiotics, viscoelastic liquids during performance of the lamellar section of the cornea, soft contact lenses, tear substitutes, and lacrimal film stabilizers during the early postoperative period.