title: Retrocorneal membranes: a comparative immunohistochemical analysis of keratocytic, endothelial, and epithelial origins.
abstract: OBJECTIVE
  To determine through the use of immunohistochemistry the origins of retrocorneal cellular and fibrillar membranes.
  
  
  METHODS
  Retrospective, clinicopathologic study using surgically removed human corneal tissues.
  
  
  METHODS
  Clinical records of patients' ocular diseases and surgical procedures were reviewed. Immunohistochemical staining was performed on 5 enucleated control globes, 32 penetrating keratoplasty specimens, and 6 Descemet stripping endothelial keratoplasty specimens to analyze: (1) the normal corneal epithelium, stroma, and endothelium; and (2) stromal scars, endothelial abnormalities, and retrocorneal membranes. Paraffin sections were stained with hematoxylin and eosin, periodic acid-Schiff, and Masson trichrome methods, and immunohistochemical analyses were performed with commonly available monoclonal and polyclonal antibodies for various cytokeratins (CKs), CD34, alpha-smooth muscle actin (SMA), and vimentin.
  
  
  RESULTS
  Five subtypes among 28 retrocorneal membranes were characterized. Twelve fibrous (keratocytic) membranes of stromal origin had coarse collagen and immunostained negatively for all CKs, but strongly for vimentin and alpha-SMA, the last the only marker of diagnostic value. Nine metaplastic endothelium-derived membranes produced delicate collagenous matrices and immunoreacted with CK7, vimentin, and alpha-SMA. Two epithelial multilaminar or monolaminar membranes reacted with CK cocktail and wide-spectrum CK, mildly with CK7 (not observed in orthotopic surface epithelium), and negatively for alpha-SMA and vimentin. The final 2 categories were indeterminate or non-immunoreactive (3 specimens) and mixed (2 specimens).
  
  
  CONCLUSIONS
  Immunohistochemistry can diagnose retrocorneal membranes of different provenances reliably in most cases. Clinical correlations established that these membranes develop after serious inflammatory disorders, prolonged wounding or ulcerations, and multiple surgeries (an average of 3.4 per patient).
authors.affiliation: Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, 243 Charles Street, Boston, MA 02114, USA. Fred_Jakobiec@meei.harvard.edu
authors.forename: Frederick A
authors.initials: FA
authors.lastname: Jakobiec
authors.forename: Pooja
authors.initials: P
authors.lastname: Bhat
mesh_terms: D000199:Actins / Q000378:metabolism; D000368:Aged; D018952:Antigens, CD34 / Q000378:metabolism; D002462:Cell Membrane / Q000473:pathology*; D003316:Corneal Diseases / Q000378:metabolism / Q000473:pathology*; D003319:Corneal Stroma / Q000378:metabolism / Q000473:pathology*; D004728:Endothelium, Corneal / Q000378:metabolism / Q000473:pathology*; D019573:Epithelium, Corneal / Q000378:metabolism / Q000473:pathology*; D005260:Female; D005347:Fibroblasts / Q000473:pathology; D006801:Humans; D007124:Immunoenzyme Techniques; D007633:Keratins / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D014746:Vimentin / Q000378:metabolism
chemical_list: C541116:ACTA2 protein, human; D000199:Actins; D018952:Antigens, CD34; D014746:Vimentin; D007633:Keratins