BASICS
DESCRIPTION
A rare condition characterized by inflammation and necrosis of the sclera. Classification:
• Anterior (93–98%)
– Diffuse (40–64%)
– Widespread inflammation of anterior segment
– Nodular (22–45%)
– Immovable inflamed nodule
– Necrotizing (13–26%)
– With inflammation (10–23%)
– Extreme pain. “Bluish sclera” due to necrosis, thinning, and increased transparency of sclera
– Without inflammation (3–4%)
– “Scleromalacia perforans.” Asymptomatic
– Posterior (2–7%)
– Associated with pain, tenderness, restricted motility, choroidal detachment, exudative retinal detachment, and disc swelling
EPIDEMIOLOGY
Prevalence
• Approximately 6 cases per 100,000
• No racial predilection
• Female to male ratio—1.6:1
PATHOPHYSIOLOGY
• Histopathology may show granulomatous or nongranulomatous inflammation, vasculitis, and necrosis.
– Antigen–antibody complexes and/or T cells have been implicated.
ETIOLOGY
• Noninfectious
– Connective tissue diseases (e.g., rheumatoid arthritis, Wegener’s granulomatosis, spondyloarthropathies, systemic lupus erythematosus), sarcoidosis, status postocular surgery, gout
• Infectious
– Herpes zoster, syphilis, tuberculosis, other bacteria (e.g., Pseudomonas in cases of scleral ulceration, Proteus associated with scleral buckle), foreign body
Although most scleral inflammation is noninfectious, bacterial or fungal organisms such as Pseudomonas and Aspergillus may cause a severe scleritis that is difficult to treat.
DIAGNOSIS
HISTORY
• Patients typically complain of deep and boring pain that often awakens them from sleep.
– May radiate to forehead, brow, or jaw
• Onset of red eye and decrease in vision may be acute or gradual in onset.
• Recurrences are common.
• Elicit history of any pertinent underlying medical problems (e.g., rheumatoid arthritis).
PHYSICAL EXAM
• Examine the sclera in all fields of gaze.
• Slit lamp evaluation for any areas of avascularity or thinning
• Check for corneal or anterior chamber involvement.
• Dilated fundus exam to rule out posterior involvement.
• Phenylephrine 2.5% test—place a drop in the affected eye and reexamine the vascular pattern in 10–15 minutes. No significant change should occur in scleritis.
DIAGNOSTIC TESTS & INTERPRETATION
Lab
Initial lab tests
CBC, rapid plasma reagin (RPR), fluorescent treponemal antibody absorption (FTA-ABS), serum antineutrophil cytoplasmic antibody (ANCA)
Follow-Up & Special Considerations
Rheumatoid factor and/or human leukocyte antigen (HLA)-B27–-in presence of polyarthritis or spondyloarthropathy
Imaging
Initial approach
Chest X-ray (CXR)—to evaluate for tuberculosis and sarcoidosis
Follow-up & special considerations
Radiograph of sacroiliac joints—if ankylosing spondylitis is suspected
Diagnostic Procedures/Other
• Purified protein derivative (PPD) with anergy panel
• B-scan ultrasound—positive “T” sign in posterior scleritis
DIFFERENTIAL DIAGNOSIS
• Anterior scleritis
– Episcleritis
– Sclera not involved, pain and associated symptoms mild if any, blood vessels tend to blanch with phenylephrine
– Posterior scleritis
– Amelanotic choroidal melanoma
– Vogt–Koyanagi–Harada syndrome
TREATMENT
MEDICATION
• Diffuse and nodular scleritis (depending on disease severity)
– NSAIDs (e.g., ibuprofen 400–600 mg p.o. q6h, naproxen 250–500 mg q12h)
– Prednisone 60–100 mg q.d. for 1 week followed by slow taper
– Immunosuppressive therapy (e.g., methotrexate, azathioprine, cyclosporine, cyclophosphamide, infliximab, mycophenolate mofetil)
• Necrotizing scleritis
– Prednisone and immunosuppressives as above
• Posterior scleritis
– NSAIDs, prednisone, or immunosuppressives as above
• Infectious
– Use appropriate topical and systemic antimicrobials
ALERT
Topical steroids are ineffective. Subtenon/subconjunctival steroids are relatively contraindicated.