title: Interference microscopy delineates cellular proliferations on flat mounted internal limiting membrane specimens.
abstract: OBJECTIVE
  To demonstrate that interference microscopy of flat mounted internal limiting membrane specimens clearly delineates cellular proliferations at the vitreomacular interface.
  
  
  METHODS
  ILM specimens harvested during vitrectomy were fixed in glutaraldehyde 0.05% and paraformaldehyde 2% for 24 h (pH 7.4). In addition to interference microscopy, immunocytochemistry using antibodies against glial fibrillar acidic protein (GFAP) and neurofilament (NF) was performed. After washing in phosphate-buffered saline 0.1 M, the specimens were flat-mounted on glass slides without sectioning, embedding or any other technique of conventional light microscopy. A cover slide and 4',6-diamidino-2-phenylindole (DAPI) medium were added to stain the cell nuclei.
  
  
  RESULTS
  Interference microscopy clearly delineates cellular proliferations at the ILM. DAPI stained the cell nuclei. Areas of cellular proliferation can be easily distinguished from ILM areas without cells. Immunocytochemistry can be performed without changing the protocols used in conventional microscopy.
  
  
  CONCLUSIONS
  Interference microscopy of flat mounted ILM specimens gives new insights into the distribution of cellular proliferations at the vitreomacular interface and allows for determination of the cell density at the ILM. Given that the entire ILM peeled is seen en face, the techniques described offer a more reliable method to investigate the vitreoretinal interface in terms of cellular distribution compared with conventional microscopy.
authors.affiliation: Vitreoretinal and Pathology Unit, University Eye Hospital Munich, Mathildenstr. 8, 80336 Munich, Germany. arnd.gandorfer@med.uni-muenchen.de
authors.forename: A
authors.initials: A
authors.lastname: Gandorfer
authors.forename: R
authors.initials: R
authors.lastname: Scheler
authors.forename: R
authors.initials: R
authors.lastname: Schumann
authors.forename: C
authors.initials: C
authors.lastname: Haritoglou
authors.forename: A
authors.initials: A
authors.lastname: Kampik
mesh_terms: D002452:Cell Count; D049109:Cell Proliferation; D002478:Cells, Cultured; D019773:Epiretinal Membrane / Q000473:pathology*; D006801:Humans; D007150:Immunohistochemistry; D008857:Microscopy, Interference; D012165:Retinal Ganglion Cells / Q000166:cytology*; D014821:Vitrectomy / Q000379:methods