Scleritis and episcleritis Flashcards
Define sclera.
Dense fibrous, protective outer layer of the eyeball. Which maintains the shape of the eyeball and provides attachment for extra-ocular muscles.
Define episcleritis.
It is a benign, self limiting inflammatory condition affecting the episclera.
Which form of episcleritis is more common?
Diffuse episcleritis
Give 2 risk factors for episcleritis.
- Female adult
- Systemic diseases
Describe the etiology of episcleritis. (5)
Idiopathic (60-70)
Collagen vascular disease(26-36)
- Rheumatoid arthritis
- Crohn disease
- SLE
Vasculitides
- Polyarteritis nodosa
Metabolic disease
- Gout
Infections –bacteria eg treponema, viruses eg herpes zoster, COVID 19
Mention the 2 types of episcleritis.
- Simple episcleritis (diffuse)
- Nodular episcleritis (focal, localized)
What are the clinical features of episcleritis?
- Redness
- Sudden onset of pain
- Photophobia
- Grittiness
- Epiphoria
- No loss of vision
How long does simple episcleritis last as compared to nodular scleritis?
Simple- 7 to 10 days (resolves after 2-3 weeks)
Nodular- can persist for more than 2 months
Define episclera.
Outer layer of the sclera that lies just beneath the conjunctiva and tenon’s capsule. This layer has blood originating from the anterior ciliary arteries.
Which test is used to differentiate episcleritis and scleritis and how is it performed?
Blanching test- Application of 2.5% of phenylephrine ophthalmic drops blanches the vessels (this does not happen in scleritis)
Give 3 differential diagnosis for episcleritis.
- Scleritis
- Conjunctival lymphoma
- Viral conjunctivitis
- Acute glaucoma
- Acute iritis
Define scleritis.
Chronic, painful, and potentially blinding inflammatory disease characterized by cellular infiltration of scleral and episcleral tissues
Which systemic autoimmune disorders is scleritis associated with?
Rheumatoid arthtitis, SLE, Wegener granulomatosis, polyarteritis nodosa,IBD
Describe the pathophysiology of scleritis.
Autoimmune mediated
-Inflammatory cell infiltration which involves release of cytokines and tissue damage. Immune complex deposition and vasculitis damages the vessels leading to ischemia and necrosis.
-Release of proteinases breaks down scleral collagen
Infectious
- Invasion by infectious agents leads to inflammation and tissue destruction
Give 4 risk factors of scleritis.
- Systemic autoimmune diseases (50%)
(Rheumatoid arthritis being the most common cause) - Trauma
- Idiopathic
- Infections –herpes zoster opthalmicus, syphilis, TB
- Surgery like scleral buckle placement
- Radiation
- Previous hx of ocular inflammation
What are the clinical features of scleritis?
- Severe, boring deep ocular pain that may radiate to the head and jaw
- Redness
- Decreased vision
- Scleral thinning
- Systemic symptoms
Which lab tests would be done in scleritis?
- Inflammatory markers: ESR, CRP
- Autoimmune screening: ANA, RF, ANCA
- Infectious workup: TB skin test, syphilis serology
- Chest x-ray
Which imaging investigations should be done for scleritis?
- B-scan
- OCT
- MRI
Give 3 differential diagnosis for scleritis.
- Allergic conjunctivitis
- Episcleritis
- Ocular rosacea
- Squamous cell carcinoma(conjunctival)
How is episcleritis managed?
Most patients require no treatment
Sunglasses
Artificial tears
Patients with severe symptoms may be given topical corticosteroids
For nodular episcleritis they may require local corticosteroid drops
Can also give systemic anti-inflammatory agents to those not responding
NSAIDs
Oral corticosteroids (if not responding after one month)
Antibiotics
Long term monitoring
Give 3 complications of scleritis.
- Uveitis
- Peripheral keratits
- Permanent visual loss
- Cataract
- Glaucoma
