The function of the iris is to regulate the amount of light that enters the eye and reaches the retina. Inflammation of the iris (uveitis) is a very serious condition that without rapid and prolonged treatment makes the cat blind to the affected eye.
Cause
Uveitis can occur due to many causes, such as Felin leukemia, FIP, Felin AIDS, toxoplasmosis (several of these are rarely seen in Sweden) and other diseases. Often, however, the cause of uveitis can not be determined.
Symptoms
Uveitis can cause everything from very mild symptoms such as slight irritation, increased production of tear fluid and light shading where no one is abnormally visible to the eye, to red and swollen mucous membrane (conjunctiva).
The cornea can become diffusely foggy and gray-blue and “spots” can accumulate which consist of white blood cells that lie on the back of the cornea. The ventricular fluid, which is located in the anterior chamber of the eye, can also become cloudy due to cells lying freely in the fluid.
The pupil may be reduced in size and the iris may be red and swollen in the acute stages. In chronic uveitis, the iris is darker and scars form inside the eye. The general condition of the cat is often affected with decreased appetite and apathy due to pain in the eye.
Therefore, contact a veterinarian quickly if you experience changes in the eye, your cat becomes light-shy, squints or has other symptoms that may give rise to suspicion of uveitis.
Diagnosis
The veterinarian can make the diagnosis through a careful examination with the help of a special instrument, called a slit lamp. This has a magnifying glass, as well as a strong light that allows you to get a detailed picture of the inside of the eye. If uveitis is suspected, the cornea, ventricles, iris and lens are examined extra carefully. The pressure in the eye is also measured, as uveitis causes inflammation in the so-called ciliary body, which produces ventricular fluid. In an uveitis, less fluid is often produced and thus the pressure in the chamber drops. The affected patient usually undergoes a full examination with blood samples as they want to find the cause of the disease, to ensure the best treatment.
Treatment
Untreated, uveitis leads to a blockage of the drainage of ventricular fluid from the eye, which leads to excessive pressure in the eye, a so-called glaucoma. This quickly leads to the destruction of the sensitive retina and the cat becoming blind.
The cause of the problem is treated first and foremost together with drops of various kinds locally in the eye. An anti-inflammatory drug is often given and in the acute stages also any cortisone that drips into the eye. Antibiotics are given when there is an infection. Inflammation of the iris requires a long course of treatment and several examinations to avoid damage to the eye.
Forecast
Uveitis is a serious eye disease, which can lead to chronic damage to the eye and cause blindness. By starting treatment early and intensively, the vision of many patients can be saved. In some cases, you can stop taking the medication after a few weeks, in other patients the treatment is lifelong. If the eye is too damaged to preserve it, the only solution may be to remove the eye, which usually does not cause problems for the cat.
Prevention
Unfortunately, there is nothing you can do to prevent uveitis. However, attention to symptoms, prompt treatment and frequent return visits give good hopes of a positive course for the cat.