title: In vivo confocal microscopy of equine fungal keratitis.
abstract: OBJECTIVE
  To describe in vivo corneal confocal microscopy of horses with fungal keratitis and correlate findings with clinical, histopathological, and microbiological evaluations of clinical cases and an ex vivo experimental equine fungal keratitis model.
  
  
  METHODS
  A total of 12 horses with naturally-acquired fungal keratitis and ex vivo equine corneas experimentally infected with clinical fungal isolates.
  
  
  METHODS
  Horses with naturally-acquired fungal keratitis were examined with a modified Heidelberg Retina Tomograph II and Rostock Cornea Module. Confocal microscopy images of clinical isolates of Aspergillus fumigatus, Fusarium solani, and Candida albicans were obtained by examination of in vitro cultures and experimentally infected ex vivo equine corneas.
  
  
  RESULTS
  Non-specific in vivo corneal confocal microscopic findings in horses with fungal keratitis included leukocyte infiltrates, activated keratocytes, anterior stromal dendritic cell infiltrates, and vascularization. Linear, branching, hyper-reflective structures that were 2-6 μm in width and 200 to >400 μm in length were detected in all horses with filamentous fungal keratitis. Round to oval hyper-reflective structures that were 2-8 μm in diameter were detected in a horse with yeast fungal keratitis. The in vivo confocal microscopic appearance of the organisms was consistent with fungal morphologies observed during examination of in vitro cultures and infected ex vivo equine corneas.
  
  
  CONCLUSIONS
  In vivo corneal confocal microscopy is a rapid and non-invasive method of diagnosing fungal keratitis in the horse. This imaging technique is useful for both ulcerative and non-ulcerative fungal keratitis, and is particularly advantageous for confirming the presence of fungi in deep corneal stromal lesions.
authors.affiliation: Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA. ecl32@cornell.edu
authors.forename: Eric C
authors.initials: EC
authors.lastname: Ledbetter
authors.forename: Nita L
authors.initials: NL
authors.lastname: Irby
authors.forename: Sung G
authors.initials: SG
authors.lastname: Kim
mesh_terms: D000818:Animals; D001228:Aspergillosis / Q000662:veterinary; D001232:Aspergillus fumigatus; D002177:Candidiasis / Q000662:veterinary; D003315:Cornea / Q000382:microbiology / Q000473:pathology; D003320:Corneal Ulcer / Q000175:diagnosis / Q000382:microbiology / Q000473:pathology / Q000662:veterinary; D015821:Eye Infections, Fungal / Q000175:diagnosis / Q000382:microbiology / Q000473:pathology / Q000662:veterinary*; D005260:Female; D005670:Fusarium; D006734:Horse Diseases / Q000175:diagnosis* / Q000382:microbiology / Q000473:pathology; D006736:Horses; D007634:Keratitis / Q000175:diagnosis / Q000382:microbiology / Q000473:pathology / Q000662:veterinary*; D008297:Male; D018613:Microscopy, Confocal / Q000662:veterinary*