The fungal plaque form of equine keratomycosis

Abstract

Objective: To describe clinical findings and visual outcomes of the fungal plaque form of equine keratomycosis. Design: Retrospective medical records study. Animals studied: Medical records of horses with the fungal plaque form of keratomycosis that presented to the University of Florida Veterinary Medical Center from 2001 to 2013 were reviewed. Procedures: Data collected for all horses with corneal fungal plaques at the University of Florida Veterinary Medical Center from 2001 to 2013 included photographs at various points during treatment, and the signalment and clinical description of ocular lesions, medical and surgical treatments, diagnostic test results, and therapeutic outcomes from medical records. Diagnosis of the plaque form of keratomycosis was based on the clinical appearance in addition to cytology and/or histologic results. Results: Twenty-two horses with keratomycosis with fungal plaques were identified. Corneal scraping found septate hyphae in all 22 eyes. Thirteen eyes (59.1%) had positive fungal culture results from the plaque. Dematiaceous fungi (n=3), Fusarium and Scopulariopsis (n=3), Aspergillus sp (n=4) and unidentified fungi or molds (n=4) were cultured from fungal plaques. Thirty-two percent (n=7) of the eyes cultured had bacterial infections in addition to the fungal infection. Fungi alone were cultured in six eyes (27.3%). Bacteria only were cultured in 6 eyes (27.3%). Culture did not reveal positive bacterial or fungal presence in three (13.7%) plaques. Medical therapy was utilized in all twenty two horses. Ninety-one percent (n=20 horses) of the horses were treated with at least one topical antifungal and at least one topical antibiotic, while one horse was treated with only topical antifungals and one horse was treated with only topical antibiotics. Nine of the horses received one topical antifungal medication and twelve received a combination of two topical antifungal medications with natamycin and either miconazole or voriconazole being the most common combination. Topical antiproteases and mydriatic/cyloplegics, and systemic nonsteroidal anti-inflammatory drugs were used in all horses. Ninety-one percent (n=20 horses) received surgical intervention of some form with 68% (n=15 horses) receiving at least one standing keratectomy and 23% (n=5 horses) receiving a superficial keratectomy under general anesthesia. Mean time to resolution was 6.5±4.1 weeks. Following medical and surgical therapy, 73% (n=16) of the eyes were visual and 27% (n=6 horses) were enucleated. The mean time to resolution of horses in which vision was preserved was 7.5±3.6 weeks. Conclusions:The visual outcome of therapy of 22 horses with the dark fungal plaque form of keratomycosis was positive in 73%. Successful treatment of the fungal plaque form of keratomycosis was aided by plaque removal, usually hastened by performing one or more keratectomies, and concurrent successful management of corneal ulceration and accompanying uveitis.

Buffaloes (Bubalus bubalis) mycotic eye infection: reported herd cases in Thi-Qar province, Iraq

“…No specific clinical signs including blepharospasm, epiphora, miosis, corneal opacity, and vascularization were observed in fungal keratitis (Ge et al, 2019). Globally, saprophytic fungi can cause mycotic keratitis in humans and animals, mainly horses (Behdad & Araghi-Sooreh, 2014;Khosravi et al, 2014;Kumar et al, 2019;Maxwell et al, 2015), cows (Handool 2013;Voelter-Ratson et al, 2013), donkeys (Nardoni et al, 2007), dogs and cats (Samuelson et al, 2010). Scarce data are available on buffaloes.…”

“…More likely, they occur in the animal's skin, residing cornea, conjunctiva, and all animal environment (Pal, 2017). Some of these fungi are pathogenic and others become pathogenic following corneal injury (Maxwell et al, 2015). The ocular microbial flora consists of resident and transient bacteria, fungi, and Chlamydia (Andrew et al, 2003;Pinard et al, 2002).…”

Equine ulcerative keratitis with furrow: A review of the outcomes of 72 cases from 1987 to 2015

“…An ABI PRISM â 310 Genetic Analyser e was then used to assess the length of the ITS2 region of the amplicon. The analyser is able to identify 12 Candida species, nine non-Candida yeasts and 21 opportunistic and dematiaceous fungi including four Aspergillus species [12,21].…”

“…While most keratomycosis cases are reported to occur during the summer and autumn seasons, diagnoses are often made year-round in tropical and subtropical climates [4,8,9]. Clinically, keratomycosis can present in many other diverse forms including keratoconjunctivitis sicca, epithelial micro-erosions, subepithelial keratomycosis, corneal ulcers with and without keratomalacia, corneal perforation, stromal plaques and non-ulcerative stromal abscesses [1,6,8,[10][11][12]. Furthermore, several different species of fungi have been linked to equine keratomycosis, each of which may result in its own unique clinical disease syndrome and associated prognosis [13].…”