Sclera Flashcards
Where is the sclera?
It starts anteriorly at the limbus and terminates posteriorly at the optic nerve.
Makes up 5/6ths of the globe
What are the 3 parts of the sclera from outer to inner?
Episclera
Substantia propria
Lamina fusca
What is the Episclera?
Outermost point, thin, vascularised connective tissue found anterior to the sclera and posterior to the tenon capsule
What is the substantia propria?
This is made up of irregularly arranged type 1 collagen fibres
What is the lamina fusca?
This is composed of loosely arranged connective tissue and is separated from the choroid by the suprachoroidal space
What innervates the anterior and posterior sclera?
Anterior - Long posterior ciliary nerves
posterior - short posterior ciliary nerves
Define episcleritis?
This is inflammation of the Episclera, which is a common self limiting condition typically affecting middle aged females. Often idiopathic
How long does simple episcleritis usually last?
Acute onset, peaks around 12-24 hours then slowly fades after a few days.
Often a localised triangular redness and discomfort.
What is nodular episcleritis?
This is a less common form of episcleritis which has an insidious onset and a longer recovery time. Red eye and discomfort commonly seen, with tender vascular nodules often seen in the interpalpebral fissure.
What is the most appropriate investigation for episcleritis?
Instillation of 10% phenylephrine blanches the redness in episcleritis.
How is episcleritis managed?
Cool compress
Oral NSAIDs
What is scleritis?
This is full thickness inflammation of the sclera which is commonly associated with certain autoimmune conditions.
What conditions are associated with scleritis?
Rheumatoid arthritis
Relapsing polychondritis
Polyangiitis and granulomatosis
infection: herpes zoster, Lyme disease, syphilis
What are the different types of anterior scleritis?
Diffuse (most common)
Nodular
Necrotising with inflammation
Scleromalacia perforans (necrotising without inflammation)
What causes a blue sclera and list some conditions associated with it:
Blue sclera is a result of underlying uvea due to scleral thinning.
- Osteogenesis imperfecta
- Ehlers-Danlos syndrome