Uveitis

Based on the part of the eye affected:

• Anterior uveitis affects the iris and ciliary body. It usually involves the front of the eye and is the most common type, making up about 75% of adult cases.
• Intermediate uveitis affects the vitreous humour. It is more common in children, teenagers, and young adults. it is also the second most common type of ocular inflammation.
• Posterior uveitis affects the choroid and the retina. This severe type can cause significant vision loss.
• Panuveitis affects the entire uvea requires immediate medical attention.

Based on the duration for which it lasts, uveitis may also be categorised as follows:

• Acute uveitis lasts for 2–3 weeks and may return.
• Chronic uveitis lasts three months or longer, and come and go.
• Recurrent uveitis occurs in repeated episodes with symptom-free gaps between each episode.

The symptoms of uveitis vary depending on the type and may range from mild to severe:

• Anterior uveitis symptoms develop within hours or days. They include:
• Aching, painful, red eye, ranging from mild eye pain to intense discomfort
• Cloudy or blurry vision
• Decreased pupil size or distortion of pupil shape
• Slight alterations in iris colour
• Sensitivity to light (photophobia)
• Headaches
• Intermediate uveitis usually affects both eyes. The symptoms of this condition include:
• Floaters (dots that move across the field of vision)
• Blurry vision
• Mild redness even when the eye looks completely normal.

Posterior uveitis usually develops slowly. Its symptoms include:

• Reduced vision and floaters
• Retinal detachment
• In some cases, loss of vision

Uveitis can be infectious and non-infectious types. Often, the exact cause of uveitis is not found. 

Some common triggers and risk factors include:

• Inflammatory or autoimmune conditions such as rheumatoid arthritis, ankylosing spondylitis, inflammatory bowel disease, or psoriasis, or other systemic conditions, including sarcoidosis, Behçet’s disease, and Reiter’s disease.
• Bacterial (tuberculosis, Lyme disease), viral (herpes simplex virus infection, shingles), fungal infections (candidiasis, aspergillosis), and parasitic infections (toxoplasmosis, filariasis).
• Immunodeficient or an immunocompromised state, which are commonly observed in patients with known underlying conditions, such as lymphoma, leukaemia, or HIV/AIDS may increase the susceptibility of these patients to eye infections.
• Juvenile idiopathic arthritis (JIA) in children is the most common cause of uveitis.

Diagnosing uveitis relies on clinical examinations and medical history. Tests may include:

• Comprehensive eye examinationsusing the slit-lamp examination and detailed medical history.
• Blood tests to detect the causative pathogen.
• Chest radiography (X-ray) to identify any underlying condition such as tuberculosis.
• Tests for rheumatoid arthritis (RA) factor, serum uric acid tests, the purified protein derivative (PPD) skin test or Mantoux test.

The choice of treatment depends on the type and underlying cause of uveitis. Common treatments include:

• Steroid medications to reduce inflammation. Steroid-based eyedrops are usually administered for treating anterior uveitis, steroid-based tablets or injections may be required for treating severe cases of anterior uveitis and several types of non-infectious posterior uveitis.
• Eye drops for pain relief or to keep pupils dilated.
• Surgery may be needed in rare cases, especially if complications such as cataracts or glaucoma. 

In most cases, patients with uveitis, especially, those with anterior uveitis, respond quickly to treatment without any long-lasting eye damage or further complications.

Patients with intermediate or posterior uveitis or those experiencing recurrent uveitis, face a higher risk of complications, such as:

• Retinal damage
• Glaucoma
• Cataract development
• Macular oedema
• Permanent deterioration of vision

Early diagnosis, consistent monitoring, and timely treatment help prevent severe complications, including permanent vision loss.

People with suspected uveitis should see an ophthalmologist, preferably one who specialises in uveitis or retinal diseases.