Corneal diseases are one of the most common ophthalmic conditions in horses worldwide. Horses are predisposed to corneal trauma due to the prominently located eyes and exposed corneas, as well as the flight behavior typical of prey species. Bacteria and fungi are ubiquitous in a normal stable environment, making horses prone to infections once corneal ulceration occurs. Infectious keratitis is often a vision-threatening process with a potential risk of loss of the eye and thus requires appropriate, aggressive intervention without delay. A recent study revealed that corneal infections were the most common primary diagnosis in horses presented for ophthalmic examination at the University of Helsinki Equine Teaching Hospital from 2019 to 2022.
In cases of infected corneal ulcers, ophthalmic samples are collected and analyzed to identify the species and antimicrobial susceptibility patterns of the causative organisms, assisting in the selection of appropriate medical management. The most common species of bacteria and fungi identified in infectious keratitis in horses varies geographically due to differing climate conditions. A recent study described the microbes and their susceptibility patterns yielded from eyes of horses treated for infectious keratitis at the University of Helsinki Equine Teaching Hospital over a period of more than ten years. These results help veterinarians working in similar climates select the empirically most effective treatment available while awaiting the results of cultures and susceptibility tests.
Immune-mediated keratitis was the second most common diagnosis in horses presenting for an ophthalmic examination at University of Helsinki Equine Teaching Hospital during 2019-2022. A recent study published in collaboration with the Royal Veterinary College (University of London, UK) compared the clinical features and outcomes in horses diagnosed with presumed immune-mediated keratitis in two different geographic locations. The results assist veterinarians in diagnosing and treating this common yet still poorly understood corneal disease.
Tonometry is an essential part of a thorough ophthalmic examination. In a recently published study, we compared the reliability and accuracy of two tonometers commonly used in veterinary practice on healthy horses.
Ophthalmic research projects are also conducted in collaboration with other research groups. For practical reasons, many ophthalmic drugs used in horses are designed for humans or other animal species. The pharmacological research of ophthalmic drugs in horses aims to gather additional information about the effects and efficacy of these drugs specifically in the horse's eye.