Uveitis

What is uveitis?
It is inflammation affecting the inside of the eye, specifically referring to the uveal tract (iris (iritis), ciliary body (cyclitis), choroid (choroiditis)).

 

Schematic eye illustration highlighting the uveal tract - the part of the eye affected in uveitis.
Schematic eye illustration highlighting the uveal tract – the part of the eye affected in uveitis.

What types are there?
Uveitis can be can be classified by:

  • Time-course of disease
    • Acute (short-lasting bouts of inflammation)
    • Chronic (long-term inflammation)
  • Which part of the eye is affected
    • Anterior (affecting the iris / front part of the eye)
    • Intermediate (mostly affecting the vitreous)
    • Posterior (affecting the vitreous, choroid and retina)
  • Cause of underlying inflammation
    • Infectious (eg bacterial, viral, fungal)
    • Non-infectious (eg auto-immune)
    • Masquerade (eg lymphoma)

What are the symptoms of uveitis?
By far the commonest uveitis is acute anterior uveitis (aka iritis). This causes pain with light (photophobia), a red eye, and sometimes blurred vision. Intermediate uveitis can cause floaters, and posterior uveitis can have a number of symptoms including loss of vision to varying degrees.

How is uveitis investigated?
Simple anterior uveitis (iritis) is usually clinically obvious to the examining ophthalmologist, and apart from examining the fellow eye (to confirm only one eye is affected) and examining the vitreous and retina (to confirm that it is purely anterior uveitis), no tests are usually necessary. Severe, recurrent, or bilateral simultaneous iritis (i.e. both eyes affected at once) can often be associated with other inflammatory conditions like ankylosing spondylitis; if this is suspected, a blood test for HLA-B27 may be ordered.

Intermediate and posterior uveitis are more likely to be associated with other conditions in the body, so more tests are often ordered, including eye tests (eg. photography, fluorescein angiography, OCT scanning) as well as more blood tests, chest X-rays, etc.

What is the treatment for uveitis?
Iritis is usually treated with eye drops alone, with steroid drops used to settle the inflammation and dilating drops used to widen the pupil and prevent (or if already present, break) adhesions between the iris and lens capsule (posterior synechiae). If the iritis is severe, can require injections of steroid underneath the conjunctiva lining of the eye. Intermediate and posterior uveitis need thorough investigation (in particular to exclude infective causes) before any treatment is started.

 

Episcleritis

This is an inflammation of one the layers of the wall of the eye, the episclera. It causes mild discomfort and redness of part of the white of the eye. It is fairly common, and usually not related to any underlying condition. It usually resolves on its own, or with tablet non-steroidal anti-inflammatories like ibuprofen. Sometimes, mild steroid eye drops are prescribed.

Scleritis

This is inflammation of the deeper layer of the wall of the eye. It is less common than episcleritis, and roughly half of cases are associated with an underlying inflammatory disorder in the body, such as rheumatoid arthritis.