Relationship between corneal flap adaptation and its reformation after intrastromal photokeratectomy

: A total of 6682 intrastromal photokeratoablations (LASIK) for myopia of 1.5-16 diopters and hypermetropia of 1.5-8 diopters are analyzed. Lamellar incision of the cornea was formed with a Hansatome microkeratotome and photokeratoablation was carried out using a Nidek EC-5000 laser. Primary and secondary deformations of a corneal flap and primary and secondary adaptation are defined. During LASIK for correction of myopia, the areas of corneal flap and corneal bed can fail to correspond to each other. This non-correspondence is the greater, the deeper is keratoablation. The corneal flap undergoes several stages of changes during the early and remote postoperative periods: primary deformation during lamellar incision, primary dysadaptation presenting as various forms of corneal dystrophy, and secondary deformation developing under new adaptation conditions. The velocity of the corneal flap adaptation depends on its reposition during the final stage of the operation, which can essentially decrease the risk of complications. The incidence of central dystrophy (pseudodiffuse lamellar keratitis) in various methods of the flap reposition varies from 0 to 1.5%.