Anterior Uveitis

Your immune system is designed to destroy bacteria, viruses and parasites and to get rid of abnormal cells such as cancer cells by a mechanism called inflammation.

Inflammation is a complex mechanism of checks and balances but sometimes, despite all the checks, the immune system starts to think that part of your body is not yourself. †Every cell in our body has proteins on the surface, which help to identify our cells to the cells of the circulating immune system. These proteins are the HLA (human leukocyte antigen). You could say it is like wearing a label on each of your cells that allows the surveillance team (our immune system) to rapidly recognize them as part of your body. When two different people share the same HLA, their tissues are immunologically compatible with each other and they can exchange tissues and cells.

If all of a sudden, your HLA label gets misinterpreted and considered as foreign, your own immune system will trigger an immune response (inflammation) against your cells and will originate an autoimmune disease.

Autoimmune diseases can affect almost any part of the body, including the eyes in HLA-B27 uveitis, one of the forms of autoimmune anterior uveitis. As ophthalmologist, we speak of anterior uveitis, when we find inflammation in the inside of the ďanteriorĒ part of the eye (the anterior chamber).

If we find a cause for this inflammation (one infection for instances), treating the cause often resolves the inflammation. Unfortunately for many patients there is not always one identifiable cause explaining the inflammatory process but thanks to the advances in drug development we can still offer some treatments that will help to control the inflammation inside the eye. In this way, we will prevent the destruction of deeper structures of the eye and maintain the vision.

Symptoms and clinical manifestations

Anterior uveitis affects the inside of the eye at the front end. The white of the eye is often pink or red with dilated vessels along the edge of the cornea (the transparent window at the centre of the eye). The anterior chamber will contain leucocytes but these are difficult to see without specialized instruments such as a slit lamp. Patients often complain of light sensitivity, bright lights making the eye painful as the iris (the colored part of the eye) constricts itself in response to light. In fact, we often give dilating drops to block the constriction, and this reduces the pain from bright lights. Vision may be blurred. This blur is partially due to the sensitivity to light but may also be caused by the inflammation itself affecting the retina at the very back of the eye.

These symptoms are subtle the first time they occur, but in people that have HLA-B27, the symptoms recur from time to time, mostly involving one eye at a time. In fact, they can usually tell when the attack of inflammation will come. If treatment is started early, it can stop the attack quickly, if not it might take much longer to control the inflammation. This is why we often test for HLA-B27 in people that have recurrent attacks.

Being examined for the first time

The eye exam in uveitis takes time. On your first visit you should expect to stay for one or more hours.

The initial part of the visit is like a visit to a general practitioner (uveitis is a condition, which often involves most of the medical fields, including ophthalmology).

We will start by a review of your medical history. Please bring along a good summary of your past medical records or even better your complete medical dossier if you have it.

Because autoimmune diseases might affect several parts of your body, we might want to examine your joints or your skin to see if there are any manifestations of inflammation elsewhere in your body. However, this is less likely with anterior uveitis.

For more information see intermediate uveitis.