Pannus, also called chronic superficial keratitis
Pannus is also known as chronic superficial keratitis. It is an immune-mediated condition affecting the cornea of the eye.
Affecting both eyes, it mainly occurs in dog breeds known to be predisposed to it such as the Berger Picard, the Belgian Shepherd, the long and short haired Collie, the Shetland Sheepdog and the Greyhound.
What are the clinical signs of pannus?
When the condition begins to manifest, a slightly raised pink mass may form on the cornea, most often on the lateral side, outside and below the eye.This mass actually corresponds to a neovascularization of the cornea, that is to say the appearance of small, long and tortuous blood vessels on the surface of the cornea.
Both eyes of the dog are usually affected, but sometimes to different degrees.
As the pathology progresses, the lesion extends to the lower half of the cornea before reaching all of it and then becomes pigmented, resulting in an opacification of the cornea. If this condition is not painful for the dog, it can, in the absence of treatment, result in the blindness of the animal.
In a quarter of cases, pannus can be accompanied by inflammation of the dog's third eyelid, also known as the nictitating membrane. The third eyelid then appears thickened and inflamed. Mucoid discharge may also be present.
What causes pannus?
Pannus is a hereditary disease, of autoimmune origin, which develops with the age of the animal.
Predisposing factors such as increased exposure to ultraviolet radiation, high altitudes and smoke are likely to contribute to the development of pannus and can certainly make it worse.
How do we treat it?
Treatment involves using topical corticosteroids or other immune-modulating drugs like cyclosporine. These treatments, which generally come in the form of drops to be instilled in the animal's eyes, help limit the progression of the disease.
Due to the influence of ultraviolet rays on the development of the disease, your veterinarian may recommend that you wear sunglasses for dogs for stays at altitude or during summer periods in order to provide extra protection for your pet.