What is autoimmune episcleritis?

Autoimmune Episcleritis: Definition, Diagnosis, and Management

Autoimmune episcleritis is an inflammatory condition of the episcleral tissue (the thin, loose, highly vascular connective tissue layer between the conjunctiva and sclera) that occurs due to an underlying autoimmune process, requiring prompt diagnosis and appropriate treatment to prevent complications. 1

Definition and Pathophysiology

Autoimmune episcleritis represents inflammation of the episcleral tissue that is triggered by an autoimmune response. Key characteristics include:

• Inflammation occurs in the thin vascular layer between the conjunctiva and sclera 2
• Often associated with systemic autoimmune conditions in up to 30% of cases 1
• More common in women and those between 40-50 years of age 2
• Can be classified into simple and nodular types, with the nodular type being more painful and prone to recurrence 2

Clinical Presentation

Patients with autoimmune episcleritis typically present with:

• Acute onset of redness in the affected eye(s)
• Mild discomfort or burning sensation
• Lacrimation (tearing)
• Photophobia (light sensitivity)
• Relatively painless compared to scleritis (important distinguishing feature) 3
• Hyperemic (reddened) sclera and conjunctiva 3
• Itching and burning sensations may occur 3

Diagnosis

Diagnosis is primarily clinical and requires careful examination to distinguish from more serious conditions like scleritis:

• Slit-lamp examination by an ophthalmologist is essential for accurate diagnosis 3
• Visual disturbance, photophobia, moderate to severe pain, or other ocular involvement should prompt immediate ophthalmologic referral 1
• Episcleritis typically presents with hyperemia of the conjunctiva and episclera without visual changes 3
• Investigations for underlying systemic autoimmune diseases may be warranted, especially in recurrent cases 4

Association with Systemic Conditions

Autoimmune episcleritis is frequently associated with systemic conditions:

• Inflammatory bowel disease (IBD) is a common association, with ocular manifestations occurring in 4-12% of IBD cases 3
• Rheumatoid arthritis and ANCA-associated vasculitides are other important associations 4
• The condition may reflect disease activity in the underlying autoimmune condition, particularly in IBD 3

Treatment Approach

Treatment should follow a stepwise approach:

1. Many cases are self-limiting and may resolve without specific treatment 3, 1

2. For symptomatic relief:

   • Cold compresses and artificial tears 2
   • Topical NSAIDs for analgesia and inflammation control 3, 1
   • Topical corticosteroids for more symptomatic cases 1

3. For cases not responding to topical therapy:

   • Systemic NSAIDs may be considered 1
   • Treatment of the underlying autoimmune condition is crucial 3, 1

4. For refractory cases:

   • Immunosuppressive treatment may be necessary, particularly when associated with systemic autoimmune disorders 2

Prognosis and Follow-up

• Most attacks resolve within 1-3 months 2
• Recurrence is common, particularly with the nodular type and in those with underlying systemic diseases 1, 2
• Unlike scleritis, episcleritis rarely leads to ocular complications or visual impairment 5
• Only 13.5% of episcleritis patients develop ocular complications, compared to 58.8% of scleritis patients 5

Important Distinctions from Scleritis

It is critical to distinguish episcleritis from scleritis:

• Episcleritis is generally benign with good visual prognosis 4
• Scleritis is potentially vision-threatening and requires more aggressive treatment 4
• Scleritis is typically more painful than episcleritis 3
• Scleritis has a higher association with systemic autoimmune diseases (40-50% of cases) 4
• Scleritis more frequently requires systemic medications including corticosteroids and immunosuppressants 5

When to Refer to an Ophthalmologist

Urgent ophthalmology referral is indicated for:

• Visual disturbance
• Moderate to severe pain
• Photophobia
• Any signs suggesting progression to scleritis 3, 1

Proper diagnosis and management of autoimmune episcleritis require collaboration between ophthalmologists and specialists treating the underlying autoimmune condition to achieve optimal outcomes.