Abstract
Abstract: :
Purpose: To describe the histopathologic and immunohistochemical findings in Keratectasias after Laser In Situ Keratomileusis (LASIK), comparing them with a typical keratoconus and a normal cornea. Methods: Cases with clinical and histopathologic diagnosis of keratectasia after LASIK were studied (1999–2003). The sections of all corneas were stained with H&E, PAS, Masson's trichrome, and Wilder's reticulin. Immunohistochemical reaction was performed using the avidin–biotin–peroxidase complex in formalin fixed and paraffin–embedded tissue. Histologic sections of all corneas were incubated with primary antibody against vimentin. Results: Six corneas with ectasia after LASIK, one keratoconus, and one normal cornea were studied. All the ectasic corneas demonstrated a thin residual stromal bed. The immunostain with vimentin was strongly positive in the superficial fibroblasts and in the total thickness of the keratoconus. The normal cornea demonstrated a focal and weak positivity to vimentin in the whole stroma. Epithelial atrophy was present in 4 of the cases with keratectasia as in the keratoconus. Other features present in the corneal ectasias were: loss of Bowman layer in 3 cases, subepithelial blebs in 2 cases, and broad fibers of collagen at the interphase in 1 case. Conclusions: Keratectasias after LASIK show superficial stromal changes better detected by vimentin reaction, indicating an increase in fibroblastic proliferation. A similar healing process was observed in the keratoconus involving the whole stroma thickness.
Keywords: cornea: stroma and keratocytes • laser • pathology: human