Anterior uveitis (acute iritis)

• Uveitis = inflammation of uveal tract (iris, ciliary body and choroid)

  Anterior uveitis = Inflammation of the iris and ciliary body

  Intermediate and posterior uveitis are less common
• An autoimmune process usually causes it, but it can be due to infection, trauma, ischaemia or malignancy.
• Pathophysiology:

  • Inflammation in the anterior chamber of the eye
  • Anterior chamber becomes infiltrated by neutrophils, lymphocytes and macrophages
  • Hypopyon = fluid collection containing inflammatory cells seen at the bottom of the anterior chamber on inspection
• The majority of cases are idiopathic. However, uveitis may occur as part of a systemic disease process:

  • HLA-B27 associated disease: inflammatory arthropathies (ankylosing spondylitis, reactive arthritis, psoriatic arthritis) and inflammatory bowel diseases
  • Other autoimmune/inflammatory diseases: interstitial nephritis, sarcoidosis, vasculitis
  • Infections: toxoplasmosis (most common), herpes simplex, herpes zoster, cytomegalovirus, tuberculosis, lyme disease, HIV and syphilis
  • Traumatic
  • Iatrogenic: surgery, medications (bisphosphonates)
  • Cancer: leukaemia, lymphoma, malignant melanoma
• Risk factors for uveitis include:

  • Aged over 20 (accounts for >90% of uveitis)
  • Previous history of uveitis
  • HLA-B27 positive
• A bilateral presentation is commonly seen in systemic conditions, whereas idiopathic or herpetic uveitis is unilateral. These can then progress to be bilateral.
• Typical symptoms of acute anterior uveitis include:

  • Painful eye - typically a dull aching pain
  • Red eye
  • Photophobia - due to ciliary muscle spasm
  • Excessive tearing
  • Reduced visual acuity
• There may also be associated systemic features including:

  • Joint pain
  • Back pain
  • A flare-up of inflammatory bowel disease
  • Infective symptoms (fever, malaise, anorexia)
• Chronic uveitis or intermediate and posterior uveitis can present more atypically with painless decreased vision.
• Anterior uveitis may be associated with underlying an autoimmune condition, particularly:

  • Seronegative spondyloarthropathies (e.g., ankylosing spondylitis, psoriatic arthritis and reactive arthritis)
  • Inflammatory bowel disease
  • Sarcoidosis
  • Behçet’s disease 
• Examination findings include:

  • Ciliary flush (a ring of red spreading from the cornea outwards)
  • Miosis (a constricted pupil due to sphincter muscle contraction)
  • Abnormally shaped pupil due to posterior synechiae (adhesions) pulling the iris into abnormal shapes
  • Hypopyon (inflammatory cells collected as a white fluid in the anterior chamber)
• Bilateral disease or systemic features require further investigation.

  Relevant laboratory investigations include:

  • Baseline blood tests: FBC, U&E, LFTs
  • Inflammatory markers: CRP & ESR
  • HLA-B27 testing
  • Antinuclear antibodies (ANA)
  • Serum ACE
  • Infectious disease screen: tuberculosis, syphilis, toxoplasmosis, lyme disease, HIV
• Suspected uveitis should be referred to an ophthalmologist for assessment within 24 hours.
• Treatment options include:

  • Topical steroid drops to reduce inflammation (frequency depending on severity)
  • Pupil dilating drops (e.g. cyclopentolate) to alleviate symptoms of photophobia
  • Treatment of the underlying cause (e.g. antimicrobials for infections)
• Cyclopentolate and atropine are antimuscarinic drugs that reduce the action of the iris sphincter muscles and ciliary muscles.
• In severe cases, systemic treatment may be required:

  • Systemic steroids: oral, intravenous, peri-ocular or intra-ocular may be required
  • Systemic immunosuppressants (e.g. methotrexate, mycophenolate, adalimumab)
• Complications:

  • Most cases of uveitis are mild and temporary
  • In severe cases there may be vision loss - macular oedema and secondary cataract
  • May be an acute rise in intraocular pressure