Inflammatory Iritis (also anterior uveitis)
What's going on?
The patient has inflammation of the iris. It is usually of an autoimmune aetiology, but in most patients no cause is identified. If it is bilateral or recurrent, a search must be made for a systemic autoimmune/inflammatory cause such as HLA-B27 related disease. The inflammation within the anterior chamber results in redness, mildly blurred vision and photophobia. If the condition is unchecked, the patient may develop a cataract or glaucoma.
If I examine the patient what will I find?
A red eye with ciliary injection (redness more around the limbus than in the inferior fornix). The pupil may be an abnormal shape due to adhesions between the iris and lens.
What if I've diagnosed it?
If patients have had many recurrences of iritis, they usually recognise the condition early (see below). Patient should ideally be referred soon for assessment. In the interim, it is reasonable to give a cycloplegic agent for comfort (NOTE: ensure the pupil is reactive and the eye is not firm; i.e., this is not angle-closure glaucoma). Topical steroids may be given if you and the patient are confident of the diagnosis. Ideally, the patient should still be assessed by the hospital eye service to confirm the diagnosis.
What will the hospital do?
Examine the anterior chamber with a slit lamp. When we see cells floating around we can make the diagnosis. We will assess the fundus to ensure that the inflammation we see at the front of the eye is not related to an inflammatory/infective process at the back of the eye. The mainstay of treatment is intensive, topical, steroid drops and dilatation of the pupil to ensure the iris does not stick to the lens. If the inflammation is severe, we may give a subconjunctival injection of steroids or even commence oral steroids. Such patients are usually reassessed after approximately two weeks to ensure the inflammation has been suppressed and to check the intraocular pressure. Long-term steroids should be avoided if possible, but sometimes when the steroids are reduced the inflammation recurs.
What do I need to do?
If the patient has had multiple episodes or has bilateral disease, they should be evaluated for an underlying systemic disorder. An autoimmune screen (HLA-B27), and chest and sacroiliac X-rays are prudent. If the patient is known to have a generalised disease, their disease control should be evaluated, as a flare-up of iritis may indicate loss of systemic control.
What to tell the patient
They have an autoimmune process in the eye whereby their body reacts against their own iris tissue. In most cases the cause is unknown and peculiar to the individual, but it is sometimes related to an underlying systemic cause. It will get better with steroids but may recur. Long-term topical steroids can cause glaucoma or cataracts and so should be avoided if possible.
Problems that may arise, and how to deal with them
Recurrence is a concern. Patients tend to recognise the symptoms quite early and can usually diagnose recurrence. Do not treat with steroids based solely upon symptoms, as the red eye may have a different cause whose symptoms will be exacerbated by steroids. If patients are started on topical steroids before the diagnosis is certain, they should be referred on for definitive diagnosis by an ophthalmologist within a few days. If the symptoms do not rapidly improve with steroids or if they worsen, the treatment should be stopped and an urgent ophthalmology review arranged. Before any topical steroids are given, the cornea should be stained with fluorescein to ensure there is no ulcer.
Children with juvenile idiopathic arthritis (JIA) are also at risk of this condition. Children present differently: the eye is white and pain-free, despite significant intraocular inflammation. For this reason, children with JIA should be screened regularly by an ophthalmologist.