Scleritis

Scleritis is a serious, potentially sight threatening inflammation of the sclera, causing severe boring eye pain and deep red violet discolouration of the eye. It is most common in women aged 30 to 60 and about 40 to 50 percent of cases are associated with systemic autoimmune disease or infection. It requires urgent ophthalmology assessment and often systemic treatment.

• Classification: anterior scleritis (about 90 percent): diffuse, nodular, necrotising with inflammation, necrotising without inflammation (scleromalacia perforans); posterior scleritis (about 10 percent).
• Systemic associations: rheumatoid arthritis (commonest, 15 to 30 percent), granulomatosis with polyangiitis and other ANCA vasculitides, systemic lupus erythematosus, relapsing polychondritis, spondyloarthropathy, inflammatory bowel disease, polyarteritis nodosa, sarcoidosis, Behçet disease, gout.
• Infections: herpes zoster ophthalmicus, tuberculosis, syphilis, Pseudomonas (post-surgical or trauma), fungi, Acanthamoeba, Lyme disease.
• Other: post-surgical (necrotising after ocular surgery), drugs (bisphosphonates, topical prostaglandins), trauma, and idiopathic (about 40 to 50 percent).
• Complications: peripheral ulcerative keratitis, anterior uveitis, cataract, glaucoma, scleral thinning and perforation, retinal detachment, optic neuropathy, macular oedema, and vision loss in about 15 to 20 percent. Necrotising scleritis carries a 5-year mortality of about 25 to 30 percent in systemic vasculitis.

• Severe boring pain, deep and constant, often radiating to the forehead, brow, jaw or temple, waking the patient at night, worse with eye movement and touch, partly relieved by oral analgesics; redness; tearing; photophobia; reduced vision in posterior or complicated disease.
• Examination: deep, violaceous or bluish red hue in natural light; engorged deep scleral vessels that do not blanch with phenylephrine 10 percent; tender globe; scleral oedema; nodules or avascular patches (necrosis) with scleral thinning showing the dark uvea; cornea and anterior chamber involvement; raised intraocular pressure.
• Posterior scleritis: pain, reduced vision, proptosis, restricted movements, exudative retinal detachment, choroidal folds, disc swelling.
• Red flags: scleral necrosis or thinning, corneal melt, visual loss, uveitis, raised intraocular pressure, associated systemic vasculitis symptoms (haematuria, sinusitis, cough, neuropathy, ulcers), history of ocular surgery, eye pain not controlled by analgesia.

• Slit lamp examination in daylight; 10 percent phenylephrine (use with caution in hypertension and cardiac disease) to confirm lack of blanching.
• B-scan ultrasound or MRI of the orbit for posterior scleritis (scleral thickening, T-sign); anterior segment optical coherence tomography.
• Systemic workup: full blood count, ESR, CRP, urea, creatinine, urinalysis, rheumatoid factor, anti-CCP, antinuclear antibody, ANCA (c-ANCA, p-ANCA), complement, syphilis serology, interferon gamma release assay, angiotensin converting enzyme, HLA B27, hepatitis serology, chest X-ray; further imaging as guided (sinus CT, chest CT).
• Culture and PCR from scleral or corneal samples in suspected infection.
• Differentials: episcleritis, orbital cellulitis, conjunctivitis, uveitis, acute angle closure, keratitis, ocular surface neoplasia, thyroid eye disease.

• Urgent (same day) ophthalmology referral; treatment is systemic, not topical alone.
• Non-necrotising anterior scleritis (diffuse or nodular):
  • Oral NSAID: indomethacin 25 to 50 mg orally three times daily with food (maximum 150 mg per day), or flurbiprofen 100 mg three times daily, or naproxen 500 mg twice daily, with omeprazole 20 mg daily. Response is expected within days to 2 weeks.
  • If no response or severe: prednisolone 1 mg/kg/day orally (maximum 60 to 80 mg) as a single morning dose, tapered over weeks, with bone, gastric and glucose protection (calcium and vitamin D, omeprazole).
  • Subconjunctival triamcinolone 4 mg (0.1 mL of 40 mg/mL) for localised disease, but avoid in necrotising disease because of perforation risk.
  • Topical steroids alone are inadequate.
• Necrotising scleritis, posterior scleritis, or systemic vasculitis:
  • Intravenous methylprednisolone 500 to 1000 mg daily for 3 days, then prednisolone 1 mg/kg/day orally with taper.
  • Add an immunosuppressant (steroid sparing agent):
    • Methotrexate 15 to 25 mg orally or subcutaneously once weekly with folic acid 5 mg once weekly.
    • Mycophenolate mofetil 1 g orally twice daily (up to 1.5 g twice daily).
    • Azathioprine 2 to 2.5 mg/kg/day orally (check thiopurine methyltransferase).
    • Cyclophosphamide 2 mg/kg/day orally or 15 mg/kg intravenously every 2 to 3 weeks for vasculitis, with mesna and hydration.
    • Rituximab 375 mg/m2 intravenously weekly for 4 weeks or 1000 mg intravenously on days 1 and 15, particularly for ANCA vasculitis.
    • Biologics such as adalimumab 40 mg subcutaneously every 2 weeks, or infliximab 5 mg/kg at weeks 0, 2, 6 and every 8 weeks, for refractory disease.
  • Monitor blood count, liver and renal function, and infection risk; give vaccinations; screen for tuberculosis and hepatitis before biologics.
• Infectious scleritis: culture directed antimicrobial therapy (for example, intensive fortified topical and oral antibiotics, antifungals or antivirals such as aciclovir 800 mg orally five times daily for 7 to 10 days in zoster disease or valaciclovir 1 g three times daily), debridement.
• Surgical: scleral patch graft for perforation or severe thinning; management of glaucoma and cataract; corneal grafting for melts.
• Pain control: analgesics, cycloplegia (cyclopentolate 1 percent twice daily) for uveitis.
• Treat the underlying systemic disease with rheumatology or nephrology.
• Review every 1 to 2 weeks initially, then monthly; monitor intraocular pressure, scleral thickness, and steroid side effects.