Scleritis

Scleritis

Scleritis is a serious and potentially sight-threatening inflammation of the sclera, the white outer layer of the eyeball. It can be caused by a variety of factors, including autoimmune disorders, infections, or trauma. Scleritis can lead to complications like vision loss if not treated promptly and effectively.

Types of Scleritis

Scleritis is classified into different types based on the severity and extent of the inflammation:

1. Anterior Scleritis (most common):
   • Affects the front part of the sclera.
   • Can be further categorized into:
     • Diffuse scleritis: Generalized inflammation of the sclera.
     • Nodular scleritis: The formation of nodules (lumps) within the sclera.
     • Necrotizing scleritis: The most severe form, where the sclera starts to break down (necrosis) and can lead to the loss of eye tissue.
2. Posterior Scleritis:
   • Affects the back part of the sclera, which is more difficult to diagnose due to its location. It can lead to significant complications, including retinal detachment.

Causes of Scleritis

Scleritis is often associated with systemic diseases, especially autoimmune and inflammatory conditions. Some common causes include:

1. Autoimmune Diseases:
   • Rheumatoid arthritis (most common).
   • Systemic lupus erythematosus (SLE).
   • Granulomatosis with polyangiitis (formerly known as Wegener's granulomatosis).
   • Ankylosing spondylitis.
   • Relapsing polychondritis.
2. Infections:
   • Bacterial, viral, or fungal infections can cause scleritis, though this is less common.
   • Herpes zoster virus (shingles) and syphilis can be associated with scleritis.
3. Trauma or Injury:
   • Physical injury or surgery to the eye can lead to inflammation of the sclera.
4. Other Factors:
   • Gout: High uric acid levels can lead to inflammation in the eye.
   • Inflammatory bowel disease (such as Crohn's disease or ulcerative colitis).
   • Infectious diseases such as tuberculosis.

Symptoms of Scleritis

Scleritis can cause severe symptoms that are distinct from other eye conditions:

• Eye pain: The pain is often deep, severe, and may radiate to the face, jaw, or head. It can be worse at night or with eye movement.
• Redness: A pronounced red or purple color in the white of the eye due to blood vessel dilation.
• Tenderness: The eye may feel tender to touch, especially in the affected area.
• Blurred vision: Vision may become blurred or distorted due to inflammation.
• Tearing: Increased tearing or watery eyes.
• Photophobia: Sensitivity to light.
• Decreased vision: In severe cases, vision can be compromised if inflammation affects deeper eye structures.

Diagnosis of Scleritis

Diagnosing scleritis typically involves:

1. Comprehensive Eye Exam:
   • An ophthalmologist will examine the eye using a slit-lamp (a specialized microscope) to assess the degree of redness, swelling, and changes to the sclera.
2. Ultrasound of the Eye:
   • For posterior scleritis, an ultrasound may help visualize the back of the eye and assess any potential damage to the retina or other structures.
3. Blood Tests:
   • These may be performed to check for underlying autoimmune diseases or infections that could be causing the inflammation, such as rheumatoid arthritis, lupus, or infection markers.
4. Imaging Studies:
   • CT scans or MRI scans may be used to evaluate posterior scleritis.

Treatment of Scleritis

The treatment for scleritis depends on the underlying cause, severity, and type of scleritis. The goals of treatment are to reduce inflammation, manage pain, and preserve vision. Common treatments include:

1. Corticosteroids:
   • Oral steroids (prednisone) are the primary treatment for scleritis to reduce inflammation.
   • Topical steroid eye drops may be used, but they are less effective for scleritis than oral steroids.
2. Immunosuppressive Drugs:
   • If scleritis is associated with autoimmune diseases or if it does not respond to steroids, other immunosuppressive medications like methotrexate, cyclophosphamide, or azathioprine may be prescribed.
   • Biologic agents, such as TNF inhibitors (e.g., infliximab), can also be used for refractory cases.
3. Nonsteroidal Anti-inflammatory Drugs (NSAIDs):
   • NSAIDs may be used for mild cases of scleritis to reduce pain and inflammation.
4. Antibiotics/Antivirals:
   • If an infection is suspected to be the cause, appropriate antibiotics or antiviral medications will be used.
5. Surgical Treatment:
   • In severe cases, surgical intervention may be necessary to repair any damage caused by necrotizing scleritis, such as tissue grafts or other reconstructive procedures.

Prognosis

The prognosis for scleritis depends on the type and severity of the condition:

• Anterior Scleritis: With early treatment, most people can maintain functional vision, although some may experience recurrent episodes.
• Necrotizing Scleritis: This form is more dangerous and can lead to permanent damage or vision loss if not treated quickly.
• Posterior Scleritis: This form can be more difficult to diagnose and treat, but with appropriate management, patients can avoid permanent damage.

If left untreated, scleritis can lead to complications like:

• Glaucoma: Increased intraocular pressure can damage the optic nerve.
• Cataracts: Long-term inflammation can lead to the development of cataracts.
• Retinal Detachment: Especially in posterior scleritis, retinal detachment may occur, which can lead to severe vision loss.
• Permanent Vision Loss: In severe or untreated cases, permanent loss of vision can occur.

Prevention

While there is no guaranteed way to prevent scleritis, the risk can be reduced by:

• Promptly addressing eye injuries and infections.
• Managing underlying autoimmune or systemic diseases (e.g., rheumatoid arthritis or lupus) with the help of a healthcare provider.
• Regular eye exams for individuals with conditions that predispose them to eye problems.

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