What Every Practitioner Should Know About the Equine Eye

Effective examination of the equine eye is a critical issue for the general practitioner because of the special requirements for safety and welfare of the horse. A riding horse for example should not have any significant visual impairment if the rider is to remain safe. At the same time the horse possibly exhibits the widest variations in the normal clinical appearance of the eye of all the species. Whilst overt pathology is usually very easy to identify because of the ease of examination of the large equine eye, possibly the biggest difficulties faced by a clinician will be determining the significance of the more subtle variations that occur in normal eyes and the milder changes that result in significant pathology. Additionally, many ophthalmic conditions are to all intense and purposes untreatable and so whilst a diagnosis may be achieved, the options for therapy are rather more limited. It is certainly true that many horses perform perfectly well with significant eye disease – not only do they adapt very well to progressive changes but the kind of work that they are required to perform, may mean that the visual efficiency is not vitally important. For example, there are some dressage horses that are virtually blind. They can survive well in a protective environment and rely heavily on the rider information – in effect, the rider is acting as a guide-animal for the horse.  [...]