Uveitis specifically refers to inflammation of the middle layer of the eye, termed the “uvea” but in common usage may refer to any inflammatory process involving the interior of the eye like the retina and vitreous. Uveitis can occur in one eye or both eyes. Inflammation of the uvea may involve other parts of the eye, or any part of the eye, including the cornea (the clear, curved front of the eye), the sclera (the white outer part of the eye), the vitreous body, the retina and the optic nerve. Many cases of uveitis are chronic, and they can produce numerous possible complications, including cataracts, lowered or raised intraocular pressure, glaucoma, retinal problems (such as neovascularization or retinal detachment), cystoid macular edema and band keratopathy. These complications can result in vision loss.
What Causes Uveitis?
Uveitis is caused due to the reaction of ones own immune system against a variety of known and unknown agents. These can be as simple to understand as trauma, bacterial, viral, fungal, protozoal and worm infections and as complex as multiple systemic autoimmune inflammatory diseases. Uveitis is estimated to be responsible for approximately 10% of the blindness in the United States. Blindness in India due to Uveitis sequelae is being increasingly recognized due to heightened awareness of uveitic conditions.
Uveitis requires an urgent referral and thorough examination by an ophthalmologist, along with urgent treatment to control the inflammation.
What are the different types of Uveitis?
Anterior uveitis: This is the commonest type of uveitis (90%) inflammation involving the iris and ciliary body. These cases usually present with a painful red eye with intense photophobia (discomfort on looking at light) and watering. There can be small pus like material in the lower part behind the cornea in advanced stage (hypopyon). The eye can also be quiet and white, but have the signs of damage due to low-grade inflammation. The inflammation may be associated with autoimmune diseases such as ankylosing spondylitis or systemic lupus erythematosus (SLE) but most cases occur in healthy people and do not indicate an underlying disease. The disorder may affect only one eye and is most common in young and middle-aged people. A history of an autoimmune disease is a risk factor.
Intermediate uveitis: In this type of uveitis, the intermediate portion of the uveal tract (ciliary body and parsplana) is affected. The patient usually has symptoms of seeing black spots. Vision loss occurs when there are changes in the central area of the retina (macula) occurring secondary to inflammation. It often occurs in association with systemic diseases like sarcoidosis, tuberculosis, multiple sclerosis, syphillis etc .It is called pars planitis when cause is not known.
Posterior uveitis: Inflammation may affect the retina (Retinitis), choroid (Choroiditis) or both (retinochoroiditis or chorioretinitis).This type of uveitis can present with a quiet looking eye or with minimal spill over inflammation in the anterior part. The inflammation may be localized (focal), at multiple sites (multifocal), widely spread (diffuse or disseminated). Patient usually has the complaint of loss of reduction of central vision (when it involves the macula) or peripheral vision. . The inflammation causes spotty areas of scarring on the choroid and retina that result in areas of vision loss. The degree of vision loss depends on the amount and location of scarring. Posterior uveitis may follow a systemic infection or occur in association with an autoimmune disease.
Panuveitis: When the entire uveal tract is involved, it is called panuveitis. This is also associated with inflammation in vitreous cavity. The condition often causes marked blurring of vision with varying degrees of pain and redness.
What are the symptoms of Uveitis?
- Redness of the eye
- Blurred vision
- Sensitivity to light
- Dark, floating spots along the visual field
- Eye pain