title: Bilateral corneal fibrosis in homocystinuria: case report and transmission electron microscopic findings.
abstract: OBJECTIVE
  To report the unusual occurrence of bilateral, superficial, corneal fibrosis with pannus formation in a young woman with homocystinuria, and to describe the light and transmission electron microscopic findings of these deposits.
  
  
  METHODS
  Excision of the corneal lesion and amniotic membrane transplantation was performed in both eyes. The excised material was studied using light and transmission electron microscopy.
  
  
  RESULTS
  Whitish, elevated, irregular masses with superficial vascularization in the peripheral cornea were noted in both eyes. Histopathologic evaluation of the excised corneal tissue revealed variable epithelial thickness with melanin pigment in the basal layer. A fibrovascular pannus, fibrosis and disruption of the Bowman's layer, and fibrosis of anterior stroma were evident. Transmission electron microscopy revealed numerous empty intracytoplasmic vacuoles in the corneal epithelial cells and intracytoplasmic inclusions containing fibrillogranular material in the cytoplasm of keratocytes.
  
  
  CONCLUSIONS
  We report the unusual association of corneal fibrosis and scarring in a young woman with homocystinuria. The deposits revealed the presence of membrane-bound inclusions containing fibrillogranular material in the corneal epithelium and keratocytes. Although the etiology of these deposits is not clear, the condition improved following excision of these lesions and amniotic membrane transplantation.
mesh_terms: D000328:Adult; D003315:Cornea / Q000473:pathology*; D003316:Corneal Diseases / Q000209:etiology* / Q000473:pathology*; D005260:Female; D005355:Fibrosis; D006712:Homocystinuria / Q000150:complications*; D006801:Humans; D008854:Microscopy, Electron