Corneal cytology as a valuable diagnostic tool in different pathological conditions of the equine cornea

Abstract

Unimpaired anatomical and physiological characteristics of the cornea are crucial for good, unrestricted eyesight. Numerous biochemical and physical functions are essential to maintain those precious properties. In order to prevent incurable changes, it is important to carefully examine and diagnose diseased cornea as early as possible. Corneal cytology provides a powerful diagnostic tool to this end, and is particularly well suited because of its quick and low invasive nature, as well as cost effectiveness.Corneal cytological sampling has to be performed with great care. It is not a very complicated procedure, but it is important to get good samples and to have an immersion oil microscope available in order to obtain as precise results as possible. The observer should be able to recognize a normal corneal sample as well as inflammatory or cancerous processes. Several slides should be prepared to use different staining’s if needed. Corneal cytology provides essential information for deciding the next steps in the diagnosis and the choice of treatment. This thesis presents a retrospective clinical study done at the Department and Clinic of Equine Medicine in Ullö, Hungary, which focuses on 37 equine ocular patients where corneal cytology was performed between January 2010 and November 2014. In summary, 13 fungal keratitis, 8 bacterial keratitis, 3 mixed keratitis, 8 chronic keratitis with epithelial dysplasia, 2 squamous cell carcinomas and 3 negative samples were diagnosed.