Keratectaia after laer in itu keratomileui (LAIK): evaluation of the calculated reidual tromal bed thickne

PURPOE: To report corneal hitopathology aociated with keratectaia after laer in itu keratomileui (LAIK) and to evaluate the thickne of the calculated reidual tromal bed in two cae and thoe in the literature. DEIGN: Interventional cae report. METHOD: Three eye of two patient developed keratectaia after LAIK. Corneal pecimen after penetrating keratoplaty in one eye of each patient were tudied hitopathologically, and the reidual tromal bed wa directly meaured. For comparion, reidual tromal bed thicknee were calculated from publihed cae of keratectaia. REULT: Two eye of a 26-year-old woman and one eye of a 22-year-old woman developed keratectaia after LAIK. Calculated reidual tromal bed thicknee were 210, 213, and 261 μm. Hitologic ection revealed focal carring in the flap plane. The cornea pecimen meaured 75 and 118 μm thinner than calculated value immediately after LAIK. Tranmiion electron microcopy of one cae revealed an average lamellar thickne of 0.94 μm. In 28 (49%) of 57 previou cae of keratectaia, the calculated reidual tromal bed thicknee were greater than 250 μm. CONCLUION: Both the flap and the tromal bed of the cornea may thin after LAIK. A reidual tromal bed thickne of 250 μm doe not preclude the development of keratectaia after LAIK.