What is uveitis?

• Uveitis is inflammation of the eye, which can present with pain, redness and blurring vision.
• If not treated, can lead to significant vision loss.
• Can affect patients of any age group or any gender.

What is Intermediate Uveitis?

• Intermediate uveitis, also known as pars planitis, affects the 'middle' area of the eye.
• The portion involves the posterior part of the ciliary body called pars plana.
• The inflammation can spread to the adjacent part of the eyeball, the iris, vitreous and retina.
• The disease usually involves young people, though the disease can occur in children as well as adults.

• The cause of the disease is still unknown in majority of the cases.
• In less than 10% cases, some association with systemic diseases, most commonly sarcoidosis, tuberculosis, multiple sclerosis has been found.
• Investigations are done to rule out the presence of systemic diseases.
• Local investigations such as fundus fluorescein angiogram and optical coherence tomography (OCT) are done to assess the status of retinal vasculature and macula respectively.

What are the symptoms of Intermediate Uveitis?

• As the disease involves the intermediate zone of the uveal tract, and remains away from the visual axis, initially patients may not have any symptoms or may only have mild blurring or floaters, which many patients probably ignore.
• There may be blurring of vision; floaters (seeing small moving objects), more rarely photophobia (difficulty in looking at the light).
• Unlike other uveitic conditions of the eye, intermediate uveitis may not have much redness or pain.
• The most common complaint is of seeing floaters.
• Vision is impaired when there are changes in the central area (macula), due to fluid collection, which occurs secondary to inflammation in the pars plana.

What are the clinical signs of Intermediate Uveitis?

• Few inflammatory cells retrolentally (in the anterior vitreous).
• Retinal examination usually reveals few opacities in the peripheral fundus. Products of inflammation (exudates) can accumulate in the peripheral fundus producing a snow bank.
• Presence of cystoid macular oedema (in about 25% of cases) due to inflammation.

Image showing inflammatory products (exudates) in pars plana region of eye.

What are the complications and course of the disease?

• In the late stages, or advanced cases patient may develop irregular pupil, cataract as a complication of uveitis.
• Significant and permanent visual loss can occur due to macular changes.
• In majority of cases around 60% had a prolonged course with exacerbations.
• Patient can develop cataract earlier and faster leading to visual loss.