Overview of Uveitis
Uveitis is a group of disorders that cause inflammation inside the eye. The inflammation affects the middle section of the eye (known as the uvea or uveal tract), which comprises:
- The iris – the coloured part of the eye
- Choroid – the layer of tissue that supports the retina and contains the eye’s blood supply
- Ciliary body – the ring of muscle behind the retina that helps the eye focus by controlling the lens
Inflammation due to uveitis is not just limited to the retina but also affects other structures in the eye, including the vitreous, and optic nerve.
Figure 1: Diagram of the eye showing the Uvea
Figure taken from https://nei.nih.gov/health/uveitis/uveitis
Uveitis is relatively rare, with a prevalence (total number of people affected) that vary by study and geographical location. The following rates have been reported for the countries below in the literature.
- 38 per 100,000 people in France
- 76.6 per 100, 000 in Finland
- 200 per 100, 000 in the United States
- 730 per 100, 000 in India
Uveitis can affect people of any age, including children, but is most common in individuals aged between 20 and 60 years of age. If untreated, uveitis is a sight-threatening condition, and accounts for up to 20% of legal blindness worldwide. It is the fifth most common cause of vision loss among working-age people in developed countries.