In vivoconfocal microscopy of equine fungal keratitis

Abstract

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.

Corneal stromal abscessation in two horses treated with intracorneal and subconjunctival injection of 1% voriconazole solution

“…Ideally, the causative organism would be identified before starting treatment as fungi can show varying responses to antibacterial and antifungal drugs. Cytologic examination of corneal scrapings, culture, in vivo corneal confocal microscopy, and polymerase chain reaction (PCR) analysis have been used to identify those microorganisms involved . Cytology, culture, and PCR analysis were not possible in this study because the lesion was deep within the posterior stroma with unaffected overlying anterior stroma.…”

“…Voriconazole has superior activity against fungi that are resistant to amphotericin B and itraconazole, and also has a good safety profile . Cutler reported that postinjection uveitis varied from severe in amphotericin injection cases to mild in that of voriconazole injections in horses.…”

Equine deep stromal abscesses (51 cases – 2004–2009) –Part 1: the clinical aspects with attention to the duration of the corneal disease, treatment history, clinical appearance, and microbiology results

“…Polymerase chain reaction (PCR) has been suggested as a method for recognizing the agent in a cytology sample or surgical biopsy . Confocal microscopy has been shown to be useful as a diagnostic tool for mycotic keratitis . In future, these methods may prove useful in providing a more accurate diagnosis of the etiology of DSA in the horse.…”

Canine Keratomycosis in 11 Dogs: A Case Series (2000–2011)

“…Common fungal isolates from equine patients with keratomycosis include Aspergillus, Fusarium, Candida, Penicillium, Cyclindrocarpon, Scyalidium, and Torulopsis, as well as yeast. 1,2 With regard to canine fungal keratitis, Aspergillus are the most common isolates, with Acremonium, Alternaria, Candida, Cephalosporium, Cladosporium, Curvularia, Fusarium, Hormographiella, Malassezia, Penicillium, Pseudallescharia, Rhodotorula, and Scedosporium occasionally reported. [3][4][5][6][7][8][9][10] Fungal organisms rarely bind to intact corneal epithelium but readily attach to stroma exposed due to a defect or ulcer.…”