What is pannus?
Pannus or chronic superficial keratitis is an immune-mediated condition affecting the cornea or clear part of the eye. It occurs primarily in middle-aged German Shepherd Dogs, but other breeds may also be affected.
What are the clinical signs of pannus?
At first, a non-painful, elevated pink mass appears on the cornea, most commonly on the lateral or outer side (if you imagine the eye to be a clock face, the mass will be found in the eight to eleven o'clock position on the dog's right eye, or the one to four o'clock position on the left eye). Both eyes are usually affected, but one may appear worse than the other. The third eyelid commonly appears thickened and inflamed. There is a variation of pannus that only involves the third eyelid called nictitans plasmacytic conjunctivitis or plasmoma. As pannus progresses, the lesion will become pigmented or dark in color, and scarring will spread over the cornea. In advanced cases, visual impairment may result due to the inability to see through the dark pigment covering the eye. If the condition is not treated, the pet will become blind.
What causes pannus?
Pannus is thought to be a hereditary condition that develops as the pet ages. Breeds such as German shepherds, Border Collies, and Long-Haired Dachshunds are the most commonly affected breeds, but pannus can occur in any breed. Predisposing factors such as increased exposure to ultraviolet light, high altitudes, and smoke contribute to the development of pannus and can exacerbate the condition.
How is pannus diagnosed?
Diagnosis is based on medical history and clinical signs. Diagnostic tests include corneal staining with fluorescein, intraocular pressure testing, and corneal or conjunctival biopsies.
How is pannus treated?
Treatment involves using topical corticosteroids or other immune modulating drugs. Antibiotics are sometimes required in cases that have developed a secondary infection. Treatment will not cure the condition, but will halt the progression and may reverse some of the changes. The treatment of pannus is lifelong. It is important that your veterinarian's instructions and medications be carefully followed and consistently administered. Once the pannus is stabilized, many dogs will be prescribed topical immune modifying drugs to help prevent recurrence. Regular check-ups and vigilance are imperative since the condition often relapses throughout life.
What is the prognosis for a dog diagnosed with pannus?
The majority of cases respond well to topical medications. Some dogs will require referral to a board-certified veterinary ophthalmologist for more aggressive treatments. In severe cases, surgery to remove the scar tissues associated with pannus may be recommended.
Based on material written by Ernest Ward, DVM. and modified with permission from Lifelearn Inc.
© Copyright 2005 Lifelearn Inc.
