Last reviewed 12/2022

The uveal tract comprises the iris, ciliary body, and the choroid. It is the middle vascular layer of the eye and is protected externally by the sclera and the cornea. The choroid is designated as the posterior part of the tract; structures preceding it, as the anterior part.

Uveitis is a general term for inflammatory disorders of the uveal tract (occasionally adjacent structures like retina, optic nerve, and vitreous humor may also be involved) (1).

It is commonly seen in people between the ages of 20-50 but can occur at any age. Around 5% of the uveitis patients are children younger than 16 years (2). One or both eyes may be affected (1).

The annual incidence is around 14-17 per 100,000. In the developed world it is the fifth commonest cause of visual loss with 10-15% of cases becoming totally blind (3).


  1. International Uveitis Study Group (IUSG). What is uveitis?
  2. de Boer J. et al. Visual loss in uveitis of childhood. Br J Ophthalmol. 2003 Jul;87(7):879-84
  3. Duranni OM et al. Degree, duration and causes of visual loss in uveitis. Br J Ophthalmol. 2004;88(9):1159-1162