Pigmentary Keratitis

a chronic disease of the cornea

What is it?
The response of the cornea to chronic irritation and/or inflammation in which pigment or melanin is deposited in the corneal epithelium (surface of the eye).

What causes it?
This condition is also one of the long term complications of eyes replaced following proptosis (traumatic displacement) and dry eye (keratoconjunctivitis (KCS)).  Other irritating factors include facial hair directed toward the eye (trichiasis), misdirected eyelashes (distichiasis), as well as acute trauma to the eye.

Who is susceptible to it?
There are many factors that make this a breed problem in the Pug and other brachycephalic (short-nosed) breeds. Anatomically, Pugs have shortened muzzles which often make for excessive nasal fold skin and shallow eye sockets which cause the eyes to protrude. Protruding eyes give rise to a condition known as lagophthalmos – the inability of the eyelids to fully cover and protect the cornea and distribute the tear film effectively.

How is it treated?
The deposition of pigment into the cornea can be permanent if the irritating problem is not resolved – - excessively long nasal folds shortened, misdirected removed, KCS treated, etc. Once the primary problems have been resolved, superficial pigment deposits can often be minimized with topical eye medications. If the pigment proves to be deep within the cornea, it is often permanent.