Diagnosis → Ophthalmology

Scleritis

Etiology

Cause [fup][zth]

• Idiopathic

• Infectious (4-10%)

  • Virus: Herpes zoster/HSV

  • Bacteria: Syphilis, tuberculosis, Lyme disease

  • Fungal: Post-trauma, surgery, immunocompromised

  • Parasite

• Autoimmune disease (50%): 

  • Rheumatoid arthritis

  • Systemic lupus erythematosus

  • Ankylosing spondylitis

  • Reactive arthritis

  • Psoriatic arthritis

  • Gouty arthritis

  • Inflammatory bowel diseases

  • Relapsing polychondritis

  • Polymyositis

  • Sjögren syndrome

  • Mixed connective tissue disease

  • Progressive systemic sclerosis

  • Polyarteritis nodosa

  • Allergic angiitis of Churg-Strauss syndrome

  • Granulomatosis with polyangiitis (Wegener granulomatosis)

  • Behçet disease

  • Giant cell arteritis

  • Cogan syndrome

• Malignancy

• Surgery (pterygium removal and scleral buckle procedures)

• Trauma

• Medications: Pamidronate, alendronate, risedronate, zoledronic acid, ibandronate

• Miscellaneous (2%): Atopy, rosacea, foreign bodies, chemical injuries

Pathophysiology [fup]

1. Trigger

   • Systemic autoimmune disease

   • Local ocular trigger (surgery/trauma/infection)

2. Scleral immune activation

   • Inflammatory cell infiltration and cytokine-mediated tissue injury

   • In necrotizing forms: vasculitis of deep episcleral/scleral vessels

3. Structural damage and extension

   • Scleral edema → severe ocular pain and deep injection

   • Scleral thinning/necrosis

   • Spillover to cornea/uvea → keratitis/uveitis, secondary glaucoma

4. Vision loss from keratitis, uveitis, glaucoma, cataract, retinal/choroidal complications

5. Necrotizing and posterior scleritis cases pose a higher risk of visual loss

Complications [zth][kvi]

• Keratopathy: Corneal thinning, keratitis, punctate keratopathy --> Decreased vision

• Iridocyclitis

• Glaucoma

• Cataract

• Fundus abnormalities: Choroidal folds, subretinal mass, disk edema, macular edema, annular ciliochoroidal detachment, or serous retinal detachment

Epidemiology

Incidence per 100.000 [fup][qun][kvi][sr2]

Default

Approach

• Slit lamp light

• Red-free light

• Differentiate from superficial episcleritis:

  • Upon installation of 2.5% topical phenylephrine in the affected eye, the blood vessels will blanch with episcleritis but will not blanch with scleritis

• Blood tests: CRP, CBC, ESR, Rheumatoid factor, ANA, ANCA, HLA-B27, IgE, uric acid, HBsAg, Quantiferon, angiotensin-converting enzyme, lysozyme

• Serology: Syphilis and Lyme disease

• Anergy skin test: Sarcoidosis

• Prick test: Atopy

• Radiology:

  • B-scan

  • Sinus films

  • CT thorax

  • CT orbita

  • MR orbita

• Scleral or corneoscleral biopsy: 

  • Necrotizing granulomatous scleritis

  • Diffuse/nodular nongranulomatous scleritis

• PCR of orbital abscess drainage, aqueous humor, and vitreous

Treatment

1. Associated disease-specific treatment [zth]

   • Rosacea

   • Gout

   • Atopy

   • Infection: Topical (and systemic) antimicrobial therapy

2. Noninfectious scleritis:

   • Topical therapy:

     • Topical corticosteroid eyedrops

     • Periorbital and subconjunctival steroid injection (often insufficient)

   • Systemic treatment:

     • 1st line: Systemic NSAIDs

       • Indomethacin 50 mg x 3 per day

       • Ibuprofen 600 mg x 3 per day

       • Naproxen 500 mg x 2 per day

     • 2nd line: Corticosteroids

       • Prednisone 1 mg/kg/day (60-80 mg/day)

       • Dose continued until one month after the resolution of scleritis

     • 3rd line: Immunomodulatory drugs:

       • Methotrexate 7.5-25 mg PO/IM once a week

       • Azathioprine 1-2.5 mg/kg/day PO

       • Cyclophosphamide 1.5-3 mg/kg/day PO

       • Mycophenolate mofetil 1 g PO bid

       • Infliximab 3-5 mg/kg IV q6-8wk

       • Adalimumab 40 mg every 2 weeks

3. Surgery may rarely be required to preserve the integrity of the globe in cases of pending perforation

   • Scleral grafts from fresh donor sclera or glycerin-preserved sclera

Differential diagnoses

Conjunctivitis, Episcleritis, Foreign body, Glaucoma, Herpes zoster, Iridocyclitis, Keratitis, Periorbital cellulitis, Rosacea, Squamous cell carcinoma, Subconjunctival hemorrhage