Treatment of equine keratomycosis, part 1: selection of appropriate therapy based on clinical presentation and diagnostic testing improves clinical outcomes.

Abstract

Objective: To determine clinical outcome, treatment costs, and hospitalization duration in horses treated for keratomycosis and identify ophthalmic examination and diagnostic results associated with these outcomes.

Methods: This was a retrospective study of 126 equine keratomycosis cases between 2004 and 2020 with fungal infection confirmed on cytology, culture, and/or histopathology and a minimum of 1-month follow-up. Details of the ophthalmic examination, diagnostic test results, and treatment and cost outcomes were recorded. Outcomes of interest were analyzed by treatment type. The relationship of patient and diagnostic test variables to the outcomes of interest was determined via logistic and linear regression models.

Results: Globe retention and positive visual outcome occurred in 82.5% and 78.9% of medically and 88.4% and 85.5% of surgically treated cases, respectively. While not statistically significant, there were more positive clinical outcomes with surgery; in recent years, the globe and vision were preserved in 94.7% of cases following penetrating keratoplasty. The choice to pursue surgery was related to lesion depth. Medical treatment was associated with statistically shorter hospitalization times and lower total and hospitalization invoices compared to all surgical treatments. Diagnosis of stromal abscess was associated with higher total invoice and longer hospitalization times compared to ulcerative keratomycosis, although clinical outcomes were similar.

Conclusions: Overall positive clinical outcomes were achieved despite the severity of the disease in many cases, highlighting the need for appropriate treatment selection based on clinical presentation.

Clinical relevance: Expanding knowledge of clinical decision-making, treatment options, and associated clinical and financial outcomes may further improve outcomes for equine keratomycosis patients.