Scleritis
Scleritis refers to inflammation of the sclera. It has a wide range of causes.
Epidemiology
It can affect age group but usually those between ages 30 and 50 years. There is a recognized increased female predilection (F:M of ~2:1).
Pathology
Information on the pathogenesis of scleritis is limited due to a lack of published data. However a predominant role for T cells in the inflammatory process has been postulated .
Associations
Scleritis can be associated with several systemic infective as well as non-infective systemic conditions which include :
- rheumatoid arthritis: 18-33%
- systemic vasculitides: 7-19%
- granulomatosis with polyangiitis: most common
- systemic lupus erythematosus: 4-7%
- inflammatory bowel disease: 4-7%
- relapsing polychondritis: 3%
- Behçet disease: rare
- sarcoidosis: rare
- cryoglobulinaemia: rare
- hypocomplementaemic urticarial vasculitis: rare
- Cogan syndrome
- herpes zoster infection: most commonly associated infection
Classification
One classification system is the Watson and Hayreh system which divides scleritis into anterior and posterior forms based upon the anatomic distribution.
- anterior scleritis
- diffuse anterior scleritis
- nodular anterior scleritis
- necrotizing anterior scleritis with inflammation
- scleromalacia perforans (necrotizing anterior scleritis without inflammation)
- posterior scleritis
Radiographic features
Ocular ultrasound
Ocular ultrasound may play a role in the diagnosis and management of posterior scleritis.
CT/MRI
CT and MRI imaging may also play a role in the diagnosis of scleritis especially during the active phase of the disease. Radiological findings include:
- scleral thickning
- scleral enhancement
- focal periscleral cellulitis