Granulomatous uveitis is a form of inflammation affecting the uvea, the eye’s middle layer, which includes the iris, ciliary body, and choroid. This condition is defined by the formation of granulomas—small clusters of immune cells that gather to wall off substances the body perceives as foreign. This type of inflammation is distinct from non-granulomatous uveitis, which does not involve granuloma formation. The presence of granulomas suggests a chronic inflammatory process often linked to underlying systemic diseases.
Clinical Presentation and Symptoms
An ophthalmologist identifies granulomatous uveitis through specific clinical signs during an eye examination. One characteristic finding is “mutton-fat” keratic precipitates, which are large, greasy-appearing clumps of inflammatory cells on the inner surface of the cornea. Another sign is the presence of nodules on the iris, known as Koeppe nodules at the pupillary margin and Busacca nodules on the iris surface.
From the patient’s perspective, the condition manifests through disruptive symptoms. Common complaints include blurred vision, mild to moderate eye pain, and photophobia, which is a marked sensitivity to light. Many individuals also report seeing floaters, which are spots drifting through the field of vision, along with general eye redness.
Associated Systemic Conditions
The inflammation in granulomatous uveitis is frequently a manifestation of a systemic disease. Sarcoidosis is a primary example, an inflammatory condition that leads to granulomas in multiple organs, including the lungs, lymph nodes, and eyes. Ocular inflammation may be the first sign of sarcoidosis, prompting a broader medical evaluation.
Tuberculosis (TB) is another significant infectious cause. The bacterium that causes TB can spread to the eye, triggering a granulomatous response as the immune system contains the infection. An eye examination can sometimes provide the first clue to an otherwise hidden TB infection, especially in regions where the disease is common.
Other systemic conditions are also linked to this eye inflammation. Vogt-Koyanagi-Harada (VKH) syndrome is a rare disorder targeting pigmented tissues in the eyes, skin, and hair, causing severe panuveitis. Sympathetic ophthalmia is another rare condition where an injury to one eye leads to a granulomatous response in both. Additionally, infections such as syphilis can cause granulomatous uveitis in later stages.
The Diagnostic Process
Diagnosing granulomatous uveitis begins with a comprehensive eye examination. A slit-lamp examination allows the doctor to magnify and inspect the eye’s anterior structures for the characteristic signs of a granulomatous cause. The exam also assesses for inflammatory cells in the anterior chamber and vitreous, the fluids inside the eye.
Because granulomatous uveitis is often linked to a body-wide condition, the diagnostic process extends beyond the eye exam to include a systemic workup. This investigation is guided by the patient’s symptoms and eye exam findings to identify or rule out common underlying causes. This often involves collaboration between the ophthalmologist and other medical specialists.
To pinpoint the underlying cause, a series of laboratory tests and imaging studies are ordered. Blood tests may be used to look for markers of specific diseases, such as measuring angiotensin-converting enzyme (ACE) levels, which can be elevated in sarcoidosis. Tests for infectious diseases like syphilis and tuberculosis are also common, along with imaging studies like a chest X-ray to check for signs of sarcoidosis or TB.
Treatment Approaches
The primary goal of treatment is to control inflammation to prevent damage and preserve vision. Corticosteroids are the main medications used to achieve this. Depending on the severity, they may be administered as topical eye drops, periocular injections, or oral medications for more widespread inflammation. These medications work by suppressing the inflammatory response.
Alongside corticosteroids, other medications manage symptoms and prevent complications. Cycloplegic eye drops are often prescribed to dilate the pupil. This relieves pain from ciliary muscle spasms and prevents the iris from adhering to the lens, a complication known as posterior synechiae.
When inflammation is chronic or difficult to control with steroids, other medications may be introduced. Immunosuppressive or immunomodulatory drugs are often used as second-line agents for long-term control. A component of the treatment plan is addressing any identified systemic disease, such as using anti-tuberculosis therapy if TB is the cause.
Long-Term Management and Prognosis
Granulomatous uveitis is often a chronic condition requiring ongoing care. Regular follow-up appointments with an ophthalmologist are necessary to watch for flare-ups and manage treatment side effects. These visits allow the doctor to adjust medications and catch emerging issues before they cause significant vision loss.
Chronic inflammation and long-term corticosteroid use can lead to other eye problems. Patients are at an increased risk for glaucoma, a condition of high intraocular pressure that can damage the optic nerve. Cataracts, a clouding of the eye’s lens, are another common complication, often accelerated by steroid use. Macular edema, or swelling in the central retina, can also occur.
Proactive management is important for a good long-term outcome. This involves treating active inflammation and consistently monitoring for these potential secondary conditions. Early detection and treatment of complications like glaucoma or cataracts can help preserve vision. The prognosis varies depending on the underlying cause, inflammation severity, and response to treatment.