Medical and Surgical Therapy of Corneal Ulcers of the Horse

Equine corneal ulceration
Equine corneal ulceration is very common in horses and is a sight threatening disease requiring early clinical diagnosis, laboratory confirmation, and appropriate medical and surgical therapy.

Ulcers can range from simple, superficial breaks or abrasions in the corneal epithelium, to full-thickness corneal perforations with iris prolapse.

The prominent eye of the horse may predispose to traumatic corneal injury.

Both bacterial and fungal keratitis in horses may present with a mild, early clinical course, but require prompt therapy if serious ocular complications are to be avoided.

Corneal ulcers in horses should be aggressively treated no matter how small or superficial they may be. Corneal infection and iridocyclitis are always major concerns for even the slightest corneal ulcerations. Iridocyclitis or uveitis is present in all types of corneal ulcers and must be treated in order to preserve vision.

Globe rupture, phthisis bulbi, and blindness are possible sequelae to corneal ulceration in horses.

Proteinases in the tear film
Tear film proteinases normally provide a surveillance and repair function to detect and remove damaged cells or collagen caused by regular wear and tear of the cornea. These enzymes exist in a balance with inhibitory factors to prevent excessive degradation of normal tissue.

Two major families of proteinases that may affect the cornea include the matrix metalloproteinases (MMP) and the serine proteinases. MMPs predominate in the horse.  [...]