The cornea helps to protect the front of the eye and is also important in focusing light on the retina at the back of the eye. Because the cornea is critical for proper vision, it is important to address any disorders or injuries promptly (see Eye Disorders of Dogs: Disorders of the Cornea in Dogs).
Inflammation of the Cornea (Keratitis)
Superficial inflammation and swelling of the cornea (superficial keratitis), inflammation and swelling within the cornea (interstitial keratitis), and inflammation and swelling of the cornea with slow-healing sores (ulcerative keratitis), can all occur in cats.
Ulcerative keratitis is frequently caused by an infection with feline herpesvirus-1. This inflammation and swelling of the cornea with slow-healing sores may occur on the surface of the cornea (superficial) or it may affect deeper layers. Initial therapy is removal of the dead, damaged, or infected tissue of the ulcer by your veterinarian, followed by topical antibiotics and other prescription medication. For resistant cases, there are surgical procedures to stimulate the replacement or development of new corneal tissue, although there are a few risks with these procedures. Your veterinarian can advise you regarding the best treatment for your cat.
Corneal Sequestration (Corneal Black Spot)
A disorder that includes darkening, inflammation, and swelling of the cornea, called corneal sequestration, appears to be unique to the cat. The condition is painful and may also involve inflammation of the cornea. There is a brown to black clouded area in or near the center of the cornea; this is composed of dead connective tissue, blood vessels, and surrounding inflammation. Corneal sequestration occurs in all breeds of cats, but Persians, Himalayans, and Burmese cats are more likely to develop the disorder. Treatment consists of removing the affected surface of the cornea and, in some cases, covering the defect with grafts of conjunctival tissue.
Deterioration or degeneration in the structure and function of the cornea occurs in cats. Degeneration often occurs in only one eye and is usually the result of other generalized or eye diseases. Treatment, if necessary, usually targets the underlying cause.
Last full review/revision July 2011 by Kirk N. Gelatt, VMD; David G. Baker, DVM, MS, PhD, DACLAM; A. K. Eugster, DVM, PhD