Pannus (Chronic Superficial Keratitis)

The cardinal sign of pannus is vascular or pigment infiltration into the clear cornea, causing whitish, pink or brown discoloration. This typically starts at the outside edge of the clear cornea nearest to the ear and extends inward. The blood vessel in-growth and pigmentation may progress across the entire corneal surface and if left untreated, may result in blindness.

An increased incidence in certain breeds (German Shepherd dog, Greyhound, Labrador Retriever, and Border Collie) suggests a genetic predisposition. Ultraviolet radiation and high altitude increase the severity of the disease. It is most common in the desert southwest and the Rocky Mountain States.

Despite intensive research efforts, no permanent cure exists. However, the vast majority of cases can be managed with topical medications that halt the disease progress and reverse corneal damage. This condition requires lifelong treatment with the best outcomes seen when therapy is instituted early. Even short periods of interrupted therapy may cause severe recurrence with profound effects on vision. Treatment categories include corticosteroid therapy, topical immunomodulatory therapy, and in severe cases, surgery.