Anterior Uveitis in Cats
Dr. Jennifer Welser
Anterior uveitis is inflammation that affects the front or anterior part of the eye called the uvea, which is the dark tissue of the eye that contains blood vessels. The iris – the tissue that makes up the pupil – is typically involved. The posterior part of the eye may or may not be affected. Immune mediated conditions in which the body attacks its own tissues
The causes of anterior uveitis include:
Infections from viruses, parasites, fungi, bacteria, and protozoa
Tumors or cancers
Trauma or injury to the eye
Metabolic disease elsewhere in the body that is affecting the eye
Idiopathic, which means the cause is unknown
Lens-induced, which is caused by the escape of lens protein into the eye fluid and is most frequently associated with cataracts
The eyes of cats are affected by more viruses than other animals. Such viruses include feline leukemia virus, feline immunodeficiency virus, and feline infectious peritonitis virus. The protozoal parasite, toxoplasmosis, is one of the most common causes of anterior uveitis in the cat.
Older cats are more likely to have tumors and indoor/outdoor pets are more likely to be exposed to infectious causes than pets housed strictly indoors. Also, in certain regions of the world specific infectious diseases are more common.
Anterior uveitis can be painful for your pet and may threaten vision. Just as important, this problem can also be a sign of a disease that is affecting the rest of the your pet's body.
What to Watch For
Squinting, especially in bright light
A small or unevenly shaped pupil
A cloudy or dull appearance in the front of the eye
An unevenly colored iris – a normal yellow-green iris may be very red, develop brown areas or have spots within it
Diagnostic tests are needed to recognize anterior uveitis, and exclude other diseases. Tests may include:
Complete medical history and physical examination
A complete examination of the eye with an ophthalmoscope, including the external portion, the front segment of the inside of the eye, and the back part of the eye.
Tonometry, which is a measurement of pressure within the eye
General blood tests, such as a complete blood count (CBC) and serum biochemical profile
Specific blood tests for immune diseases, infectious agents or other systemic diseases
Ultrasound, X-rays or aspirates, which are samples of fluid taken from inside the eye via a small needle
Treatments for anterior uveitis may include symptomatic or specific therapy and surgical intervention:
Symptomatic therapy, regardless of the cause of the anterior uveitis, is usually indicated. Topical treatments like drops or ointments placed on the eye and oral medications are designed to reduce pain and inflammation – like treating a headache with aspirin regardless of what is causing the headache.
Specific therapy is directed if a cause for the anterior uveitis has been determined. Appropriate topical and/or oral drugs are prescribed and may include an anti-fungal drug or a drug that reduces immune mediated inflammation.
Surgical intervention. In situations where there is a tumor or secondary complications (such as glaucoma) that cannot be controlled with medications, surgery to remove the eye may be necessary.
Home Care and Prevention
It is important that you follow your veterinarian's instructions and learn to medicate your pet properly. It is not always easy to put medications into an animal's eye, but it is imperative the medications be given.
Examine your pet's eyes every day and look for subtle changes. See your veterinarian for follow-up appointments to re-examine eye.
You have some control over your pet's environment. Cats can be protected from many of the infectious diseases that cause anterior uveitis by keeping them indoors.
Prevent trauma to eye; use caution when throwing balls or other objects.