ANATOMY - SCLERA

Question 1

What are the main properties of the sclera?

Answer 1

Outer fibrous coat of eye, avascular and acellular structure apart from some fibroblsats.

it is covered by tenon’s capsule.

Question 2

Where is the sclera the thickest?
Where is the sclera the thinnest?

Answer 2

Thickest - posteriorly around nerve
Thinnest - around EOM insertions

Question 3

Where is the most common site of scleral rupture following blunta trauma?

Answer 3

Area parallel with limbus on opposite side of the impact (contre-coup effect)

Question 4

What is the sclera derived from embryologically?

Answer 4

mesenchymal condensations around optic cup.

Question 5

At what age is the scleral spur formed by embryologically?

Answer 5

5 months

Question 6

What type of collagen is seen in scleral stroma?

Answer 6

Irregular collagen lattice (Types 1 and 3)

Question 7

What is the blood supply of the episclera?

Answer 7

Anterior ciliary artery, long and short posterior ciliary arteries

Question 8

What is the structure of the sclera?

Answer 8

Episclera - below tenon’s capsule, vascularised layer.

Scleral stroma: irregular arranged fibres so sclera is opaque

Lamina fusca - inner scleral layer containing melanocytes (migrated from choroid), separated by choroid by suprachoroidal space.

Question 9

What is the anterior continuation of sclera?
What is posterior continuation of sclera?

Answer 9

Anterior: Conjunctiva
Posterior: Tenon’s capsule