The sclera is the tough, protective outer layer of the eyeball, known as the “white” of the eye. Scleritis is a condition where this layer becomes inflamed. This is a serious issue that can signal a deeper, body-wide health problem. Due to its severity and risk of complications, scleritis requires prompt medical evaluation by an ophthalmologist.
Symptoms and Types of Scleritis
The defining symptom of scleritis is a severe, deep, and boring eye pain that can disrupt sleep and radiate to the jaw, face, or head. Accompanying the pain is an intense, purplish redness of the white of the eye. Other symptoms include light sensitivity (photophobia), blurred vision, and excessive tearing.
Scleritis is classified based on the location and severity of the inflammation. The main types include:
- Anterior scleritis: The most common form, affecting the front of the sclera. It can be widespread (diffuse) or appear as a firm, tender lump (nodular).
- Posterior scleritis: A rarer form affecting the back of the sclera. It may not cause visible redness but can lead to vision problems like floaters, retinal detachment, or glaucoma.
- Necrotizing scleritis: The most severe form, which destroys scleral tissue and thins the eye wall. A rare, painless type called scleromalacia perforans can cause holes in the sclera.
Underlying Causes of Scleritis
In about half of all cases, scleritis is linked to a systemic autoimmune disease, where the body’s immune system mistakenly attacks its own tissues. The most common associated disorders include:
- Rheumatoid arthritis
- Systemic lupus erythematosus (lupus)
- Granulomatosis with polyangiitis
- Inflammatory bowel disease (IBD)
- Sjogren’s syndrome
- Scleroderma
Scleritis can also arise from other sources. Infections caused by bacteria, fungi, or viruses can trigger the inflammation. Trauma or injury to the eye, including complications from surgery, can also lead to scleritis.
In a significant number of instances, the specific cause cannot be identified. When no underlying disease, infection, or injury is found, the condition is referred to as idiopathic scleritis.
How Scleritis Is Diagnosed
Diagnosing scleritis begins with a comprehensive eye examination by an ophthalmologist. The doctor will use a slit lamp, a microscope providing a magnified view of the eye’s structures, to inspect the sclera. This allows the doctor to observe the deep, purplish redness and any nodules or thinning of the scleral tissue.
To help differentiate scleritis from the less severe episcleritis, the ophthalmologist may apply phenylephrine eye drops. In episcleritis, the superficial blood vessels will constrict and turn white, while the deeper inflamed vessels in scleritis remain red.
Blood tests are a standard part of the diagnosis due to the strong association with systemic diseases. These tests check for inflammatory markers and specific antibodies that indicate an underlying autoimmune disorder.
When posterior scleritis is suspected, imaging tests are required to see the back of the eye. A B-scan ultrasound, CT scan, or MRI may be used to visualize the inflammation and check for related complications.
Managing and Treating Scleritis
The goals of scleritis treatment are to control inflammation, alleviate pain, and prevent complications like vision loss or eyeball perforation. The approach is staggered based on severity. For milder cases, the first line of defense is high-dose non-steroidal anti-inflammatory drugs (NSAIDs).
For more significant inflammation, oral corticosteroids like prednisone are commonly prescribed to reduce swelling and pain. Topical steroid eye drops are not effective on their own for the deep inflammation of scleritis.
In severe or recurring cases, or when linked to a systemic autoimmune disease, stronger medications are necessary. These can include immunosuppressive drugs to dampen the immune response or newer biologic therapies that target specific parts of the immune system.
Addressing any identified underlying cause is a fundamental part of management. If an autoimmune disease is diagnosed, treatment will be coordinated with a rheumatologist to manage the systemic condition. In the rare event of severe scleral thinning or perforation, surgery may be required to repair the eye wall using a scleral graft.