The symptoms of uveitis depend on which part of the uvea is affected. In general, early uveitis symptoms may include:

• Blurred vision
• Eye pain or aching
• Eye redness
• Floaters (tiny dark spots, lines, or squiggles that seem to drift across your vision)
• Light sensitivity

Untreated uveitis can cause vision loss and other complications, such as:

• Cataracts
• Cystoid macular edema
• Glaucoma
• Retinal detachment

Approximately 50% to 70% of all uveitis cases occur for unknown reasons (idiopathic). Known causes of uveitis include infections, autoimmune conditions, and eye injury.

Risk factors for uveitis
A risk factor is anything that increases the chance of developing a disease or condition. Risk factors for uveitis may include:

• Age between 20 and 60 years, although uveitis can occur at any age
• Certain medications, such as bisphosphonates used to treat bone loss, etanercept used to treat immune conditions, female hormone replacement therapy, and specific antibiotics and cancer medications
• Genetic factors associated with the human leukocyte antigen B27 protein (HLA-B27)
• Smoking

Types of uveitis are based on the structures in the uvea affected by inflammation. Types of uveitis include:

• Anterior uveitis: Inflammation occurs in the front part of the uvea and mainly affects the iris. Anterior uveitis is the most common type.
• Intermediate uveitis: Inflammation occurs in the middle part of the uvea. It affects the ciliary body and vitreous humor, a clear, gel-like fluid that fills the eye behind the lens.
• Posterior uveitis: Inflammation occurs in the back part of the uvea and affects the retina, choroid, and optic nerve.
• Panuveitis: Inflammation occurs in all parts of the uvea.

Uveitis is also classified based on how quickly the symptoms develop or how long they last.

• Acute uveitis symptoms happen suddenly and last fewer than three months.
• Chronic uveitis symptoms often develop gradually and last longer than three months.
• Recurrent uveitis means that symptoms come and go, with periods of inactivity lasting three months or longer between flares.

While you can’t always prevent uveitis, there are some steps you can take to decrease the chance of developing it, reduce the chance of flare-ups, and prevent vision loss. These preventive measures include:

• Avoid smoking
• Detect and treat underlying causes of uveitis early, such as autoimmune diseases or infections
• Get regular eye exams
• Maintain a healthy lifestyle with regular exercise and a balanced diet
• Take vitamin D supplements if levels are low
• Use protective eyewear during sports or when working with hazardous materials to prevent eye injury or trauma

Eye doctors check for uveitis through an eye exam that includes:

• Medical history review: Your doctor asks about any recent infections, current medications, or other health conditions that might cause uveitis.
• Slit lamp exam: This test is part of a routine and diagnostic eye exam. Your doctor focuses a beam of light toward your eye to check the structures in the front of the eye, such as the sclera, cornea, and lens.
• Ophthalmoscopy with pupil dilation: This test is an additional part of a slit lamp exam. The doctor uses special eye drops to dilate or widen the pupils. Dilating the pupils allows the doctor to check the structures deep in the back of the eye, such as the retina and optic nerve.
• Tonometry: This test measures pressure inside the eye (intraocular pressure) to check for glaucoma.

Imaging studies can help detect signs of uveitis and identify potential causes. Imaging studies that can detect signs of uveitis may include:

• Color fundus photography: This test takes colored pictures of the inside of the eye.
• Fluorescein angiography or indocyanine green angiography: The doctor injects dye through an intravenous (IV) needle into a vein in your arm. The dye travels to the blood vessels in the back of your eyes, allowing for clearer pictures of swollen blood vessels.
• Optical coherence tomography (OCT): OCT uses a laser to detect inflammation in the blood vessels of the choroid or retina. OCT angiography also shows blood flow.

Imaging studies that can detect potential causes of uveitis may include:

• Chest X-ray: A chest X-ray produces images of the chest and lung tissue using radiation and can detect lung infections, such as tuberculosis.
• Neuroimaging: Neuroimaging, including magnetic resonance imaging (MRI) of the brain and spinal cord, can help doctors identify signs of multiple sclerosis.

Your doctor may recommend specific blood tests to detect underlying infections or autoimmune conditions that could cause uveitis. Blood tests may include:

• Antinuclear antibody testing to detect certain autoimmune diseases
• C-reactive protein (CRP) testing, which checks for inflammation or infection
• Infectious disease testing, such as blood tests to confirm HIV, syphilis, or tuberculosis
• Rheumatoid factor (RF) testing, which detects rheumatic diseases, including rheumatoid arthritis

Your doctor may recommend a biopsy if the cause of uveitis is unclear. They collect a tissue or fluid sample from inside the eye and send the sample to the lab for testing. Lab findings can help your doctor better understand the condition causing your uveitis.