Acute Iritis

Accepted definition/diagnostic criteria Acute iritis, also known as anterior uveitis, is characterised by inflammation of the iris, the coloured part of the eye. It can be idiopathic or associated with systemic diseases such as ankylosing spondylitis, sarcoidosis or inflammatory bowel disease. The diagnosis is primarily clinical, based on symptoms and eye examination findings, including ciliary flush, photophobia and pain.

Epidemiology Acute iritis is the most common form of uveitis, accounting for approximately 50-60% of cases. It predominantly affects individuals aged 20-40 years and has no significant gender predilection. The annual incidence in the UK is estimated to be approximately 20 per 100,000 population.

Diagnosis
Clinical features: Patients typically present with unilateral ocular pain, redness, photophobia, and decreased vision. A key clinical feature is the presence of a ciliary flush (red ring around the iris) and irregular pupil due to posterior synechiae. Slit-lamp examination reveals cells and flare in the anterior chamber, which are hallmark signs of the condition.

Investigations: While diagnosis is largely clinical, additional investigations can be performed to identify underlying systemic associations and rule out infectious causes. These may include blood tests (e.g., HLA-B27, rheumatoid factor, ANA), chest X-ray and syphilis serology. Typical abnormalities include elevated intraocular pressure, and protein and cells in the anterior chamber.

Treatment Treatment aims to reduce inflammation, relieve pain, prevent complications and treat the underlying cause if identified. Topical corticosteroids are the mainstay of treatment for reducing intraocular inflammation. Topical cycloplegics (e.g., cyclopentolate) are used to relieve pain and prevent the formation of posterior synechiae. Systemic corticosteroids or immunosuppressive agents may be required for severe cases or systemic involvement. Regular follow-up is essential to monitor response to treatment and adjust therapy as needed.

Prognosis The prognosis for acute iritis is generally good, especially with prompt and appropriate treatment. However, recurrent episodes are common, and complications such as cataract formation, glaucoma and permanent vision loss can occur if not adequately managed. Long-term monitoring is important for detecting and managing these complications .