2-24 - Episcleritis vs Scleritis Flashcards
Episcleritis
- General information
- Who’s more likely to get
- Causes
- Symptoms
- Inflammed at Tenon’s BVs + episclera
- Idiopathic usually (rarely from infection, may be due to underlying systemic disease)
- Common, benign, self-limited, recurrence high (doesn’t progress to scleritis)
- Mostly young to middle aged women
- Unilateral mostly (bilateral possible)
Symptoms: - Redness
- Discomfort
- Lacrimation
- NO discharge or papillae/follicles (unlike cojunctivitis)
Episcleritis
- Two types
Simple episcleritis
- Most common
- Either sectoral (local area more red) or diffuse (equal redness around episclera)
- Spontaneous resolution
Nodular episcleritis
- Tender, congested red nodule + injection around area (salmon-pink as oppose to conjunctivitis’ bright red appearance)
- Slightly mobile over sclera
- Self-limited, but lasts longer
- Note: Blue colour from nodular episcleritis due to rearrangement of collagen to be more regular, increasing transparency, allowing blue of underlying uveal tissue to be seen. Not confused w/ scleral thinning which is also blue.
Scleritis
- General information
- Signs and symptoms
- Who’s more likely to get
- Oedema + cellular infiltrate of whole sclera
- Non-infectious most common cause (strong associated w/ systemic inflammatory/autoimmune disease)
- Women more likely (due to above), men more likely to have infectious cause, 40s – 60s yrs
- Can spread to uveal structures or cornea and visual impairment possible
- Less common, large range of visual outcomes, so always treat seriously.
Symptoms: - Redness
- Lacrimation
- Severe, consistent “boring” pain that radiates, doesn’t resolve w/ painkillers, worse at night
- Reduced vision
- Photophobia
Signs: - Violaceous (purple) hue
Anterior non-necrotizing scleritis: Diffuse
Widespread vascular congestion + dilation w/ possible oedema
- Redness local or widespead
- Similar to simple episcleritis
- Characteristic distortion of radial vascular pattern (resulting from irregularly oriented deep vascular plexus disrupting the nice superifical episcleral plexus pattern)
- Benign, recurrence common until underlying cause treated. Doesn’t progress to anything else.
Anterior non-necrotizing scleritis: Nodular
- Local granulomatous inflamm
Resembles nodular episcleritis except: - Nodules single or multiple, can expand + coalesce (painful)
- Deeper blue-red colour, soft tender
- Can’t move over underlying tissue (unlike nodular episcleritis)
- Visual impairment present in 25%, >10% become necrotizing.
Anterior necrotizing scleritis: w/ inflammation
- Worse scleritis type (most severe + aggressive)
- Older onset age (60yrs average)
Progression: - Distorted deep vascular plexus -> poor blood flow -> clot (occluded) -> avascular patches. Note: The distorted deep vascular plexus also disrupts the superificial episcleral plexus.
- Scleral necrosis -> spread + coalesce
- Scleral thinning = blue tinge
- Associated w/ underlying systemic, life-threatening, vasculitis
- Poor visual and mortality prognosis (25% die within 5 years)
Anterior necrotizing scleritis: w/o inflammation
Progression:
- Necrotic, yellow plaques w/ no inflammation
- Enlargement, spread, coalesce -> slow progressive sclera thinning
- Bulging staphyloma formation can occur (if high IOP)
- Typically in women w/ longstanding RA
- Bilateral, asymptomatic (no pain unlike other ant. scleritis)
- No Tx ;-;
Posterior Scleritis
- General information
- External features
- Fundus features
- How to diagnose
- Uncommon, often misdiagnosed
- 85% get vision impairment
- Bilateral sometimes, +/- pain
External: - Eyelid oedema, ptosis (if closer to ant. sclera)
- Proptosis (eye appears to buldge outwards)
- Ophthalmoplegia (EOM paralysis), orbital myositis (EOM inflamm), diplopia + pain when eye moves
Fundus: - ONH swelling, macular oedema
- Choroidal folds
- Exudative RD
Diagnose: - via OCT, US, or CT to find thickening sclera
- US shows “T sign” where fluid accumulates under sub-Tenon space and optic nerve shadowing
