Bright Sight

Oliver Backhouse, Consultant Eye Surgeon www.cataract.org.uk

Uveitis Investigations

If you have read the ‘Uveitis in General’ information you will have understood that there are many different types of uveitis. Working out what type of uveitis one has is important as it can help the specialist give you information regarding how it may behave in the future, how long it may last for and how it may respond to treatments such as Steroids.

Some of the more common investigations that may be asked for in clinic are written below with a brief explanation of the usual reason why it has been requested. The majority of cases of Uveitis have a completely normal set of investigations. Occasionally a test result may come back from the laboratory as abnormal but this may not directly help define or confirm the exact type of Uveitis. The interpretation of the results is very important as it is only one part of the jigsaw puzzle that helps direct treatment. Results can also be falsely positive as well as falsely negative.

  • Full Blood Count (FBC) – bacterial / viral / parasitic infections.
  • Urea and Electrolytes (U&Es) – can reflect kidney involvement.
  • Glucose – if raised can indicate Diabetes. Important if Steroids to be used.
  • Plasma Viscosity (PV) – marker of general systemic inflammation.
  • Angiotensin Converting Enzyme (ACE) – Sarcoidosis usually.
  • Syphilis Serology
  • Chest X-ray (CXR) – Mainly for Sarcoidosis or Tuberculosis.
  • Antinuclear antibody (ANA) – Autoimmune conditions.
  • Antineutrophil cytoplasmic antibodies (ANCA) – Wegners granulomatosis.
  • Mantoux Test / Quantiferon Test – Tuberculosis.
  • Toxoplasma Dye Test – Toxoplasmosis.
  • Toxocara Test – Toxocara.
  • High Resolution Chest CT scan – Sarcoidosis.
  • MRI Scan – Demyelination, Lymphoma, Sarcoidosis.
  • Fundus Fluorescein Angiography (FFA) – Better deifine choroid inflammation
  • Optical Coherence Tomography (OCT) – to detect macular oedema.
  • Electrophysiology - Birdshot Retinochoroidopathy
  • HLA B27 – Ankylosing Spondylitis, Reiters, Psoriasis.
  • HLA A29 – Birdshot Retinochoroidopathy
  • Intraocular fluid DNA analysis – Herpetic acute retinal necrosis
  • Vitreous Biopsy – Lymphoma, Amyloid
  • Cerebrospinal fluid analysis – Demyelination, Lymphoma, VKH Syndrome.

In some patients the investigation screening is negative initially but can then become positive several years later. For this reason tests may be repeated. It should be remembered that in the majority of patients no ‘definitive’ diagnosis can be made even after extensive investigation. It is often the history and examination that give the better clues. Investigations are most helpful when done for specific reasons rather than an unhelpful blanket screen.