title: Contribution to comprehension of image formation in confocal microscopy of cornea with Rostock cornea module.
abstract: OBJECTIVE
  To investigate the influence of refractive index of aqueous humour on imaging of corneal endothelium in confocal microscopy. To clarify the phenomenon of dark endothelial and bright epithelial cell membranes in confocal images of corneas.
  
  
  METHODS
  Use of a novel digital confocal laser scanning microscope, a combination of the Heidelberg retina tomograph (HRT II) and the Rostock cornea module. Exchange of aqueous humour solution from domestic pigs against glycerol/water solutions (refractive indices eta = 1.337-1.47). Transelectron microscopy of endothelial and epithelial cell morphology.
  
  
  RESULTS
  Under the terms of variable refractive indices no differences were observed for general imaging of endothelium. Bright cells were bordered by dark cell membranes in all experiments. Electron microscopy of endothelium and epithelium revealed differences in intracellular and cell membrane structure of both cell types.
  
  
  CONCLUSIONS
  Source of specific confocal optical behaviour of endothelium does not come from interface conditions to aqueous humour, but may result from intracellular variations and ultrastructure of cell membranes.
authors.affiliation: Department of Ophthalmology, University of Rostock, Doberaner Strasse 140, 18055 Rostock, Germany. ralf.bo@t-online.de
authors.forename: R
authors.initials: R
authors.lastname: Bochert
authors.forename: A
authors.initials: A
authors.lastname: Zhivov
authors.forename: R
authors.initials: R
authors.lastname: Kraak
authors.forename: J
authors.initials: J
authors.lastname: Stave
authors.forename: R F
authors.initials: RF
authors.lastname: Guthoff
mesh_terms: D000818:Animals; D001082:Aqueous Humor / Q000502:physiology; D003315:Cornea / Q000502:physiology / Q000648:ultrastructure*; D004728:Endothelium, Corneal / Q000502:physiology / Q000648:ultrastructure; D019573:Epithelium, Corneal / Q000502:physiology / Q000648:ultrastructure; D005990:Glycerol / Q000737:chemistry; D018613:Microscopy, Confocal; D008854:Microscopy, Electron; D012031:Refractometry; D013552:Swine; D014054:Tomography; D014867:Water / Q000737:chemistry
chemical_list: D014867:Water; D005990:Glycerol