Uveitis refers to inflammation of the middle layer of the eye, which is called the uvea.
The uvea is made up of the iris (the coloured part of the eye), the ciliary body (a ring of muscle behind the iris), and the choroid (a vascular layer of tissue that supports the retina).
Uveitis usually causes a red, painful eye with cloudy vision. These symptoms may vary in intensity from mild to severe. The type of uveitis may be categorised according to which part of the eye is affected.
Anterior uveitis: Refers to inflammation of the iris (iritis) or inflammation of the iris and the ciliary body (iridocyclitis). It is the most common type of uveitis, accounting for 75% of cases in adults.
Intermediate uveitis: This affects the area behind the ciliary body and the retina. It tends to occur in children, teenagers and young adults.
Posterior uveitis: This is a severe form of uveitis which affects the back of the eye i.e. the choroid and the retina, and can seriously affect vision.
Panuveitis is a type of uveitis that affects the entire uveal tract i.e. inflammation of both the front and the back of the eye at the same time. This form of uveitis can be sight threatening.
Uveitis can also be acute, lasting for a few weeks; or chronic, lasting for more than three months, and recurring symptoms that can vary over time.