OP5.1-2 | Sclera — Glossary

Anti-cyclic citrullinated peptide antibodies; more specific than rheumatoid factor for rheumatoid arthritis; positive earlier in the disease course and predict joint erosion.

Antibody to double-stranded DNA; highly specific for SLE; elevated titres correlate with disease activity and risk of lupus nephritis.

Antineutrophil cytoplasmic antibody with cytoplasmic staining pattern, directed against proteinase 3; highly specific for granulomatosis with polyangiitis (GPA/Wegener's).

An alkylating immunosuppressant used for severe ANCA-associated vasculitis (GPA) and necrotising scleritis; high toxicity (haemorrhagic cystitis, opportunistic infection, malignancy risk) requires careful monitoring.

A thin layer of loose, vascular connective tissue lying between Tenon's capsule and the outer scleral surface; rich in blood vessels, responsible for the bright-red appearance in episcleritis.

Inflammation of the episclera — the thin, loose vascular connective tissue layer between Tenon's capsule and the scleral surface; benign, self-limiting, and associated with bright-red sectoral injection that blanches with phenylephrine 2.5%.

An oral NSAID (100 mg three times daily) used for nodular episcleritis and as first-line systemic treatment for diffuse and nodular anterior scleritis.

Formerly Wegener's granulomatosis; a systemic necrotising granulomatous vasculitis associated with c-ANCA, affecting the upper and lower respiratory tract and kidneys; one of the most important systemic associations of scleritis.

Episcleral inflammation occurring in patients with inflammatory bowel disease (Crohn's disease or ulcerative colitis); may parallel intestinal disease activity; one of the most common systemic associations of episcleritis.

A topical NSAID (0.5% eye drops) used as a second-step therapy in episcleritis when lubricants are insufficient; inhibits prostaglandin synthesis in the episcleral vasculature.

A folate antagonist used as a disease-modifying antirheumatic drug (DMARD) for RA; first-line immunosuppressant for RA-associated scleritis not adequately controlled by NSAIDs.

A form of episcleritis characterised by a discrete, slightly raised, tender, mobile nodule of inflamed episcleral tissue; more prolonged and recurrent than simple episcleritis.

Antineutrophil cytoplasmic antibody with perinuclear staining pattern, directed against myeloperoxidase; associated with microscopic polyangiitis and eosinophilic granulomatosis with polyangiitis (Churg-Strauss).

Melting/ulceration of the peripheral corneal stroma adjacent to an area of scleritis; a sight-threatening complication of severe scleritis associated with systemic vasculitis.

Instillation of phenylephrine 2.5% eye drops to distinguish episcleritis from scleritis; episcleral vessels (superficial) blanch within 1-2 minutes, whereas deep scleral vessels do not.

An autoimmune condition causing episodic inflammation of cartilaginous structures (ear pinna — but sparing the non-cartilaginous earlobe — nasal cartilage, tracheal rings); scleritis and episcleritis are recognised ocular complications.

A chimeric anti-CD20 monoclonal antibody that depletes B-lymphocytes; used for GPA-associated and refractory RA-associated scleritis; increasingly preferred over cyclophosphamide for GPA in remission induction.

Collapse of the nasal bridge due to destruction of the nasal cartilage; a classical clinical sign of GPA or relapsing polychondritis; should prompt ANCA testing and urgent systemic evaluation in any patient presenting with scleritis.

Referenced case-series establishing that approximately 50% of scleritis patients have an underlying systemic disease; a foundational reference for understanding the systemic associations of scleritis.

Inflammation of the sclera — the dense, collagen-rich outer coat of the eye; characterised by severe boring pain, deep violaceous injection that does not blanch, and frequent association with systemic autoimmune diseases such as rheumatoid arthritis and granulomatosis with polyangiitis.

Necrotising scleritis without inflammation — a paradoxically painless form of scleritis occurring almost exclusively in women with longstanding rheumatoid arthritis; characterised by progressive scleral thinning and avascular grey-yellow plaques without active signs of inflammation.

The more common form of episcleritis presenting as diffuse sectoral bright-red episcleral injection without nodule formation; usually lasts 2-3 weeks and resolves spontaneously.

A pathognomonic ultrasonographic finding in posterior scleritis: echo-free fluid in the sub-Tenon's space adjacent to the posterior globe creates a T-shaped configuration at the optic nerve on B-scan.

A fibroelastic fascial sheath enclosing the posterior eyeball; lies between the conjunctiva and the episcleral tissue.

The characteristic bluish-red (purple-red) colour of the scleral vessels in scleritis, reflecting deep congestion in poorly-vascular scleral stroma; distinguishes scleritis from the bright-red episcleral injection of episcleritis.

The standard clinical classification of scleritis (1976) dividing it into anterior (diffuse, nodular, necrotising with inflammation, necrotising without inflammation) and posterior subtypes.