Scleritis: Symptoms, Types, Causes and Treatment

Scleritis is a rare but potentially sight-threatening inflammatory eye disease that affects the sclera—the tough, white outer wall of the eye. While uncommon, scleritis is notable for its severe pain, potential association with systemic illnesses, and the risk of permanent vision loss if not promptly diagnosed and treated. In this article, we will provide a comprehensive overview of scleritis, focusing on its symptoms, the various types, underlying causes, and current treatment strategies. Drawing on recent research, we aim to empower patients, caregivers, and clinicians with up-to-date knowledge on this complex ocular condition.

Symptoms of Scleritis

Scleritis often presents with dramatic and distressing symptoms, making it distinct from other, more benign eye conditions. However, due to its rarity and overlap with other ocular diseases, early recognition can be challenging. Understanding the key symptoms is essential for timely intervention and prevention of complications.

Symptom	Description	Frequency/Severity	Source(s)
Pain	Severe, deep, boring eye pain	Moderate to severe, often worse at night; may radiate to face and head	1, 2, 3, 4, 10, 12, 15
Redness	Diffuse or localized scleral redness	Persistent, not relieved by vasoconstrictors	1, 3, 4, 6, 10, 12, 15
Vision Loss	Blurred or decreased visual acuity	May be transient or permanent, worse in necrotizing or posterior types	1, 3, 6, 9, 15
Photophobia	Sensitivity to light	Common, varies by severity	4, 6, 12
Tearing	Increased lacrimation	Less specific symptom	3, 6

Table 1: Key Symptoms

Pain: The Hallmark of Scleritis

Severe, deep, and persistent pain is the most characteristic symptom of scleritis. Unlike the mild discomfort of conjunctivitis or episcleritis, scleritis pain is often described as "boring" and may radiate to the jaw, forehead, or temple. It typically worsens at night and may not respond to over-the-counter pain medications. In studies, over two-thirds of patients reported moderate to severe pain at presentation 1, 2, 3, 4.

Redness and Inflammation

Redness in scleritis is more intense than in typical eye irritation and is due to engorgement of the deeper episcleral and scleral vessels. Unlike conjunctivitis, the redness does not move when the conjunctiva is moved and is not relieved by vasoconstrictor eye drops 1, 3, 4, 6.

Visual Changes

Visual impairment can range from mild blurring to significant vision loss, especially in necrotizing or posterior forms of the disease. Visual loss is more frequent in infectious scleritis and in cases associated with complications such as uveitis, keratitis, or glaucoma 1, 3, 9.

Photophobia and Tearing

Sensitivity to light (photophobia) and increased tearing are common but less specific. These symptoms often accompany redness and pain, especially in anterior scleritis 4, 6, 12.

Other Symptoms

• Eye tenderness (pain on touching the eye)
• Swelling of the surrounding tissues, such as the eyelids
• In posterior scleritis: less obvious redness, but with possible proptosis (eye bulging), double vision, or decreased vision 3, 4

Types of Scleritis

Scleritis is not a uniform disease; it encompasses several subtypes, each with distinct clinical features, risks, and prognoses. Understanding the types is vital for diagnosis and guiding therapy.

Type	Main Features	Risk/Complications	Source(s)
Diffuse Anterior	Generalized redness and swelling of the sclera	Most common, moderate risk	1, 4, 6, 7, 14, 15
Nodular Anterior	Localized, firm, tender nodule(s)	Good visual prognosis if treated	1, 2, 4, 6, 7, 14
Necrotizing	Areas of scleral thinning and tissue death; may/may not have inflammation	High risk of vision loss and complications	1, 4, 6, 7, 14, 15
Posterior	Inflammation behind the eye; less visible redness, more visual symptoms	Often misdiagnosed, risk of vision loss	3, 4, 7, 8, 15

Table 2: Main Types of Scleritis

Anterior Scleritis

Anterior scleritis is the most common form, accounting for the majority of cases 1, 4, 6. It is subdivided into:

• Diffuse anterior scleritis: Widespread inflammation without a focal nodule. Presents with generalized redness and pain.
• Nodular anterior scleritis: Characterized by one or more localized, raised, tender nodules on the sclera.
• Necrotizing anterior scleritis: The most severe form, with areas of white, avascular sclera (tissue death). Can be with or without visible inflammation (necrotizing scleritis with or without inflammation).

Necrotizing scleritis carries the highest risk of vision loss and is most often associated with underlying systemic autoimmune disease 1, 4, 6, 14.

Posterior Scleritis

Posterior scleritis affects the back portion of the sclera, often making diagnosis more challenging as redness may be less obvious or absent. Symptoms may include deep eye pain, reduced vision, and sometimes signs such as proptosis or retinal detachment. Posterior scleritis is often underdiagnosed or misdiagnosed as other ocular conditions such as conjunctivitis or orbital cellulitis 3, 4, 7, 8.

Scleritis in Children

While rare, scleritis does occur in children. Posterior idiopathic scleritis is the most common pediatric subtype, but anterior and necrotizing forms can also occur. The presentation may differ from adults, necessitating a careful and multidisciplinary diagnostic approach 7.

Causes of Scleritis

Scleritis is a disease with diverse causes, involving both immune-mediated and infectious processes. Identifying the underlying cause is crucial for effective management and for addressing associated systemic health risks.

Cause Type	Subtypes/Examples	Relative Frequency/Importance	Source(s)
Autoimmune	Rheumatoid arthritis, granulomatosis with polyangiitis, HLA-B27 diseases, Sjögren's syndrome, systemic lupus erythematosus	Most common cause (30–40% of cases have systemic autoimmune disease)	4, 6, 8, 10, 11, 15
Infectious	Herpes viruses, tuberculosis, bacteria (e.g., Nocardia)	5–10% of cases; important to differentiate	1, 2, 5, 9, 12
Idiopathic	No identifiable cause	Up to 50% of cases	1, 5, 6, 15
Pediatric/Other	Sarcoidosis, Behçet’s disease, JIA	Variable, especially in children	7, 11

Table 3: Causes of Scleritis

Autoimmune and Systemic Disease Associations

Most cases of scleritis are associated with immune-mediated diseases. The most frequent is rheumatoid arthritis, found in up to 18.5% of patients in large cohorts 6, 11. Other significant associations include granulomatosis with polyangiitis (formerly Wegener’s granulomatosis), HLA-B27-associated diseases (ankylosing spondylitis, reactive arthritis), and Sjögren's syndrome 8, 10, 11, 15. Scleritis may be the first sign of such systemic diseases, making thorough evaluation essential.

Infectious Causes

Infectious scleritis is less common (around 5–10% of cases) but is critical to recognize, as management differs fundamentally from immune-mediated forms. Herpes viruses are the most frequent pathogens, but bacteria (such as Nocardia), tuberculosis, and fungi can also be responsible 1, 2, 9, 12.

Notably, infectious scleritis may initially be misdiagnosed as noninfectious, leading to inappropriate immunosuppression and worse outcomes 9, 12. Necrotizing forms and cases with delayed healing or atypical features should raise suspicion for infection.

Idiopathic Scleritis

Up to half of scleritis cases have no identifiable underlying cause even after extensive work-up. These idiopathic cases are diagnosed by exclusion and may still require aggressive treatment 1, 5, 6, 15.

Pediatric and Rare Causes

In children, scleritis may be associated with juvenile idiopathic arthritis, sarcoidosis, Behçet’s disease, or may remain idiopathic. Prompt diagnosis is crucial to prevent vision loss and to address systemic conditions 7, 11.

Treatment of Scleritis

Treatment of scleritis aims to control inflammation, alleviate symptoms, preserve vision, and prevent complications. The therapeutic approach depends on the underlying cause, severity, and disease subtype.

Treatment	Indication/Subtype	Notes/Effectiveness	Source(s)
NSAIDs	Mild-moderate, non-necrotizing, idiopathic or mild autoimmune	First-line for less severe cases; may not suffice for severe disease	4, 6, 14, 15
Corticosteroids	Moderate-severe or refractory cases; both topical & systemic	Mainstay for acute inflammation; oral or IV for severe/necrotizing	3, 4, 6, 14, 15, 16
Immunosuppressants	Severe, necrotizing, or systemic autoimmune disease	Methotrexate, azathioprine, mycophenolate mofetil, cyclophosphamide, etc.	4, 6, 13, 14, 15, 16
Biologic agents	Refractory or relapsing cases	TNF inhibitors (e.g., infliximab), rituximab; effective in resistant disease	8, 13, 14, 15, 16
Antimicrobials	Infectious scleritis	Must be tailored to organism; corticosteroids contraindicated unless infection controlled	1, 2, 9, 12
Surgery	Severe complications (e.g., scleral thinning, perforation)	Adjunct to medical therapy; rare	2, 9, 14, 15

Table 4: Treatment Approaches

Anti-Inflammatory and Immunosuppressive Therapy

• NSAIDs are often effective for mild to moderate, non-necrotizing, idiopathic or autoimmune anterior scleritis. Examples include ibuprofen and indomethacin. However, many cases require escalation due to insufficient response 4, 6, 14, 15.

• Corticosteroids are the mainstay for moderate to severe scleritis, necrotizing forms, or posterior scleritis. Administration may be topical, periocular, oral, or intravenous, depending on severity. Long-term use is limited by side effects 3, 4, 6, 14, 15, 16.

• Immunosuppressive agents such as methotrexate, azathioprine, mycophenolate mofetil, and cyclophosphamide are reserved for severe, necrotizing, or refractory cases—especially when associated with systemic autoimmune disease 4, 6, 13, 14, 15, 16.

• Biologic agents (e.g., TNF inhibitors like infliximab, rituximab) are increasingly used for scleritis unresponsive to conventional immunosuppression, with good outcomes in refractory cases 8, 13, 14, 15, 16.

Infectious Scleritis Management

Prompt identification of infectious scleritis is crucial, as corticosteroids or immunosuppressants can worsen infection. Treatment requires targeted antimicrobial therapy based on the causative organism. Surgical intervention may be needed for abscesses or necrotic tissue 1, 2, 9, 12.

Monitoring and Multidisciplinary Care

Successful management often involves collaboration between ophthalmologists, rheumatologists, infectious disease specialists, and sometimes pediatricians. Monitoring for complications, treatment side effects, and underlying systemic disease is essential 4, 6, 7, 15, 16.

Special Considerations in Pediatrics

Children with scleritis require tailored treatment, with attention to growth, development, and the potential for underlying systemic disease. Multidisciplinary evaluation is especially important in this age group 7.

Conclusion

Scleritis is a complex, potentially blinding condition that demands early recognition, accurate diagnosis, and individualized management. Its presentation can mimic less severe eye diseases, but the consequences of delayed or inappropriate treatment can be severe. Understanding its symptoms, types, causes, and treatment options is essential for both clinicians and patients.

Key Points:

• Symptoms: Severe eye pain, redness, visual impairment, photophobia, and tearing are common.
• Types: Includes diffuse anterior, nodular anterior, necrotizing, and posterior scleritis; each carries different risks and requires specific management.
• Causes: Most cases are autoimmune or idiopathic; up to 10% are infectious—making accurate diagnosis crucial.
• Treatment: Ranges from NSAIDs and corticosteroids to immunosuppressive drugs and biologics; infectious cases require antimicrobials. Multidisciplinary care ensures optimal outcomes.

Timely diagnosis and a tailored, evidence-based approach can significantly improve quality of life and preserve vision for those affected by scleritis.