Anterior uveitis is one of the important differentials of a red eye. It is also referred to as iritis. Anterior uveitis describes inflammation of the anterior portion of the uvea - iris and ciliary body. It is associated with HLA-B27 and may be seen in association with other HLA-B27 linked conditions (see below).


  • Incidence: 40.00 cases per 100,000 person-years
  • Peak incidence: 30-40 years
  • Sex ratio: 1:1
Condition Relative
Anterior uveitis1
Microbial keratitis0.50
Acute angle closure glaucoma0.25
<1 1-5 6+ 16+ 30+ 40+ 50+ 60+ 70+ 80+


Associated conditions
  • ankylosing spondylitis
  • reactive arthritis
  • ulcerative colitis, Crohn's disease
  • Behcet's disease
  • sarcoidosis: bilateral disease may be seen

Clinical features

  • acute onset
  • ocular discomfort & pain (may increase with use)
  • pupil may be irregular and small
  • photophobia (often intense)
  • blurred vision
  • red eye
  • lacrimation
  • ciliary flush
  • hypopyon; describes pus and inflammatory cells in the anterior chamber, often resulting in a visible fluid level
  • visual acuity initially normal → impaired


  • urgent review by ophthalmology
  • cycloplegics (dilates the pupil which helps to relieve pain and photophobia) e.g. Atropine, cyclopentolate
  • steroid eye drops