Uveitis refers to inflammation of a structure inside the eye called the uveal tract. The uveal tract lines the inside of the eye. It is the only structure within the eye containing blood vessels. At the front of the eye it is called the iris, at the back of the eye it forms a structure under the retina called the choroid. A specialised part between the front and back is called the ciliary body and produces fluid inside the eye.
When the uveal tract become inflamed, blood cells and debris leak out into the internal fluid filled chambers of the eye, resulting in cloudiness and loss of vision in severe cases. Clinical signs of uveitis include cloudiness of the cornea, redness around the edge of the eye, tearing, squinting, bleeding into the eye, and loss of vision.
Uveitis in the dog and cat can be associated with any generalised infectious or inflammatory process within the body. Other causes include trauma or leakage of proteins from ageing cataracts.
In dogs typical causes include:
- uterine infections in females
- prostatic infections in males
- infectious hepatitis virus
- systemic fungal infections
In cats the causes can include:
- Feline Leukemia Virus
- Feline Immunodeficiency Virus
- Feline Infectious Peritonitis virus
However, many patients with uveitis do not have an obvious underlying cause. Often we will recommend pathology tests to identify an underlying cause.
Severe uveitis can result in vision threatening complications such as cataract formation, adhesions of the iris to the lens or cornea, retinal disease, and glaucoma. Treatment for uveitis is aimed at reducing the inflammation and preventing the complications. The treatment protocol will vary for each patient but may include topical and/or oral cortisone, oral non-steroidals to reduce inflammation, atropine to alleviate the pain associated with smooth muscle spasm inside the eye, and sometimes medication to prevent glaucoma.