Scleritis is a serious inflammatory condition affecting the sclera, the tough, white outer layer of the eye. While it can sometimes occur in isolation, scleritis is frequently a manifestation of underlying systemic diseases, particularly those involving the immune system. Identifying the root cause of scleritis is important for effective treatment and to address any broader health issues.
Understanding Scleritis
Scleritis involves inflammation of the sclera. This inflammation often leads to severe eye pain, which can sometimes radiate to the jaw or temple and may worsen with eye movement. Other common symptoms include pronounced redness of the white part of the eye, sensitivity to light, increased tearing, and blurred vision. Untreated scleritis can lead to vision loss.
There are two main types of scleritis: anterior scleritis, which affects the front of the eye, and posterior scleritis, impacting the back. Anterior scleritis is more common and can present in various forms, including diffuse (widespread redness), nodular (localized painful lumps), or necrotizing (the most severe form, causing tissue destruction). Posterior scleritis is rarer and can be more challenging to diagnose due to its varied symptoms, which may include deep-seated headaches or double vision.
Autoimmune Conditions Associated with Scleritis
Scleritis is often linked to autoimmune diseases, where the body’s immune system mistakenly attacks its own healthy tissues. Approximately 36% to 44% of scleritis cases are associated with these systemic conditions.
Rheumatoid arthritis (RA) is the autoimmune condition most frequently associated with scleritis. RA is a chronic inflammatory disorder primarily affecting joints, but it can also manifest in the eyes, sometimes even before joint symptoms appear. Systemic lupus erythematosus (SLE) is another connective tissue disease where scleritis can be a presenting feature. Lupus involves chronic inflammation that can disrupt various organ systems, including the eyes.
Granulomatosis with polyangiitis (GPA) is a rare form of vasculitis that can cause severe scleritis, often as one of its initial manifestations. This condition involves inflammation of blood vessels and can lead to tissue damage in multiple organs. Relapsing polychondritis is a rare immune-mediated disease characterized by recurrent inflammation of cartilage throughout the body, and scleritis, often bilateral and necrotizing, can be a significant ocular manifestation.
Inflammatory bowel disease (IBD), including Crohn’s disease and ulcerative colitis, causes chronic intestinal inflammation. Scleritis can occur in IBD patients, sometimes mirroring their bowel disease activity or appearing independently. Ankylosing spondylitis (AS) primarily affects the spine but can also cause eye inflammation, including scleritis, though uveitis is more common. Psoriatic arthritis (PsA), a form of arthritis affecting some people with psoriasis, can also be associated with scleritis.
The Autoimmune Link to Scleritis
One primary pathway is systemic inflammation, where the immune system generates widespread inflammatory reactions throughout the body. This generalized inflammation can extend to the sclera, causing the characteristic redness, pain, and swelling observed in scleritis. Immune complex deposition is another mechanism, where antibodies and antigens form complexes that can settle in various tissues, including the sclera. These deposits trigger an inflammatory cascade, leading to tissue damage. Vasculitis, or inflammation of blood vessels, can also contribute to scleritis by impairing blood flow to the sclera, leading to tissue ischemia and necrosis in severe cases.
Diagnosing and Managing Scleritis
Diagnosing scleritis involves a comprehensive eye examination, often using a slit lamp microscope to closely inspect the sclera. Identifying any underlying autoimmune conditions is crucial, often requiring additional investigations like a medical history review and blood tests for specific autoimmune markers.
Managing scleritis involves controlling eye inflammation and treating the underlying systemic autoimmune disease. Eye inflammation treatment often includes systemic corticosteroids to reduce the immune response. Immunosuppressants may also be prescribed for severe or recurrent cases to modulate immune activity. Collaborative care between an ophthalmologist and a rheumatologist or other relevant specialist is important for effective diagnosis and long-term management of both the eye condition and the systemic disease.