Damage to epithelial basement membrane by thermokeratoplasty.

To determine the effects of thermokeratoplasty (TKP) on the basement membrane complexes of the corneal epithelium, transmission electron microscopy was performed on the corneal buttons of five patients with failed TKP and on two normal corneas and five corneas with keratoconus that were immediately treated by TKP (acute TKP). The consistent findings of thermal dissolution of basement membrane after acute TKP and persistent defects of basement membrane complexes many months after therapeutic thermokeratoplasty were significant. Given the potentially damaging effects of thermokeratoplasty on the epithelial basement membrane, faulty epithelial adhesion should be anticipated after thermokeratoplasty and should be treated aggressively, possibly with careful prophylactic use of bandage hydrophilic contact lenses.