• Scleritis is a painful, inflammatory process of the sclera, part of the eye’s outer coat.
    • Categorized into anterior or posterior and diffuse, nodular, or necrotizing
    • Commonly associated with systemic disorders
    • Potentially vision threatening
  • In contrast, episcleritis is a self-limited inflammation of the superficial episclera with only mild discomfort.
  • System(s) affected: ocular


  • Mean age is 54 years (ranges from 12 to 96 years).
  • Predominant sex: female > male (1.6:1)

Estimated to be 6 cases per 100,000 people in the general population


  • Anterior scleritis, about 94% of cases (1)
    • Diffuse anterior scleritis, about 75% (most common)
  • Remaining 6% have posterior scleritis.

Etiology and Pathophysiology

  • Frequently associated with a systemic illness (1)[B]
    • Most commonly associated with rheumatoid arthritis
    • In about 38% of cases, scleritis is the presenting manifestation of an underlying systemic disorder.
    • Necrotizing scleritis has the highest association with systemic disease.
  • Other etiologies
    • Proposed pathogenesis is dependent on type of scleritis. In necrotizing scleritis, the predominant mechanism is likely due to the activity of matrix metalloproteinases.
    • Drug-induced scleritis has been reported in patients on bisphosphonate therapy.
    • Surgically induced necrotizing scleritis is exceedingly rare and occurs after multiple surgeries.
    • Infectious scleritis occurs most commonly after surgical trauma, and Pseudomonas aeruginosa in poorly controlled diabetic patients is the most common causative organism (2)[B].

Risk Factors

Individuals with autoimmune disorders are most at risk.

Commonly Associated Conditions

  • Rheumatoid arthritis (most common)
  • Sjögren syndrome
  • Granulomatosis with polyangiitis
  • HLA-B27–associated ankylosing spondylitis
  • Systemic lupus erythematosus
  • Behçet disease
  • Juvenile idiopathic arthritis
  • Cogan disease
  • Relapsing polychondritis
  • Polyarteritis nodosa
  • Sarcoidosis
  • Inflammatory bowel disease
  • Herpes zoster, herpes simplex
  • HIV, syphilis, Lyme disease, tuberculosis

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