What Is Scleritis?

Patients search for scleritis because their red eye hurts in a way that ordinary irritation does not: a deep, relentless ache that pain relievers barely touch and that keeps them up at night. Many have been treated for conjunctivitis without improvement and sense something is different. Those with a known autoimmune disease are often told their eye problem may be connected to it, and they want to understand what the sclera is and why its inflammation is taken so seriously.

The sclera is the dense, collagen-rich white wall that gives the eye its shape. When it becomes inflamed, the inflammation is deep and the pain is correspondingly deep and severe, quite different from the surface stinging of conjunctivitis or the mild ache of episcleritis. The affected area often takes on a bluish or violaceous tinge because the inflamed deep vessels show through, and the eye is tender to touch.

Because the sclera is structural, scleritis can damage the eye in ways surface conditions cannot. Prolonged or severe inflammation can thin the wall, and in necrotizing scleritis the tissue can break down to the point of perforation. Nearby structures can be drawn in, causing corneal thinning, inflammation inside the eye, glaucoma, or swelling at the back of the eye, any of which can reduce vision. This structural threat, combined with links to serious systemic disease, is why scleritis is taken seriously.

Scleritis is classified by location and severity. Anterior scleritis, the most common, may be diffuse, nodular, or necrotizing; necrotizing scleritis is the most dangerous because it destroys scleral tissue and can perforate. Posterior scleritis inflames the back of the eye and can cause pain, blurred vision, and swelling that is easy to miss without imaging. Across these, the deep pain, tenderness, and non-blanching deep redness distinguish scleritis from the milder, superficial episcleritis.

About half of scleritis cases are associated with a systemic disease, and it is often the presenting sign. Rheumatoid arthritis is the most common association; others include granulomatosis with polyangiitis and other vasculitides, systemic lupus, relapsing polychondritis, and inflammatory bowel disease. Some cases are infectious, particularly after eye surgery or trauma, or from herpes zoster. Necrotizing scleritis and scleritis tied to vasculitis are the most concerning, because they reflect aggressive systemic disease and carry the highest risk to the eye. Diagnosing scleritis therefore means both treating the eye and searching for its cause.

Scleritis is inherently serious and warrants prompt care. Certain features raise the urgency further:

• Deep, severe, boring pain that wakes you from sleep or radiates to the face, with a deeply red, tender eye.
• Decreased vision, worsening light sensitivity, or a bluish, thinned-looking patch of the white of the eye.
• Rapidly worsening pain or redness, which can indicate the necrotizing form.
• Scleritis in someone with known vasculitis or rheumatoid arthritis, which may reflect a dangerous flare.

These should be evaluated urgently, because tissue thinning and perforation, though uncommon, are vision- and eye-threatening.

The doctor distinguishes scleritis from episcleritis at the slit lamp, often using a phenylephrine drop: it blanches the superficial vessels of episcleritis but not the deep scleral vessels of scleritis, which stay red and tender. The exam assesses the depth and pattern of inflammation, looks for scleral thinning, and checks the cornea, the inside of the eye, and eye pressure for associated damage; posterior scleritis may require ultrasound or other imaging to detect. Because scleritis so often signals systemic disease, evaluation includes a workup for autoimmune and infectious causes, commonly rheumatoid and vasculitis markers (such as ANCA) and tests for relevant infections, with care coordinated alongside a rheumatologist.

Non-necrotizing scleritis is usually treated first with oral nonsteroidal anti-inflammatory medication, stepping up to oral corticosteroids if needed. More severe, recurrent, or necrotizing scleritis, and scleritis associated with vasculitis, requires steroid-sparing immunosuppressive or biologic therapy managed with a rheumatologist, both to control the eye and to treat the underlying disease. Infectious scleritis is treated with the appropriate anti-infective therapy rather than immunosuppression alone. Complications such as corneal thinning, glaucoma, or perforation are managed directly and occasionally require surgical repair. Because scleritis reflects systemic disease so often, treating that disease is central to controlling the eye and preventing recurrence.

• Do not treat a deeply painful red eye as pink eye or wait it out; scleritis needs prompt medical care.
• Do not rely on over-the-counter redness-removing or allergy drops to quiet a deep, boring, painful red eye.
• Do not ignore a connection to a known autoimmune disease; scleritis may mean that disease is flaring.
• Do not stop prescribed anti-inflammatory or immunosuppressive treatment early, as scleritis commonly recurs when treatment is cut short.

Call promptly if you have a red eye with deep, severe, boring pain, especially pain that wakes you at night or radiates to your face, with light sensitivity or reduced vision. May Eye Care Center, serving the Hanover, Pennsylvania area, can distinguish scleritis from milder inflammation, start treatment, and arrange the workup for an underlying autoimmune cause in coordination with your rheumatologist.

Scleritis is a deep, severely painful inflammation of the white wall of the eye that can threaten the eye and often signals autoimmune disease, so it needs prompt evaluation and treatment rather than being mistaken for ordinary red eye.