uvea choroid

Question 1

general arrangement of choroid

Answer 1

• A vascular pigmented layer between sclera and retina (middle coat of the eye)
• Extends anteriorly from the ora serrata to the edge of optic disc

Question 2

function of choroid

Answer 2

• Suprachoroidal space provides a route for blood vessels to the anterior uvea
• High blood flow through choroidal vessels regulates eye temperature
• Supplies metabolites & removing waste products from the outer layers of the retina
• Choroidal pigments absorb light that passed through retina, prevent internal reflection
• Innermost layer (Bruch’s membrane) provides basement membrane for retinal pigment epithelium

Question 3

choroid layers (furthest to closest from retina)

Answer 3

1. suprachoroid
2. stroma
3. choriocapillaris
4. Brunch’s membrane

Question 4

suprachoriod

Answer 4

• Loosely attaches to the sclera giving rise to the suprachoroidal space
  > Suprachoroidal space: Contains the long posterior ciliary arteries & ciliary nerves that travel to supply the anterior uvea
• consists of collagen fibres that are continuous form sclera, melanocytes & fibroblast

Question 5

choroidal stroma

Answer 5

• Pigmented layer consists of loose connective tissue and blood vessels containing melanocytes, fibroblasts, collagen, macrophages, lymphocytes
• Within this layer blood vessels divided into
  > Haller’s layer, external layer of large diameter blood vessels
  > Sattler’s layer, internal layer of smaller diameter blood vessels

Question 6

choriocapillaris

Answer 6

• Single layer of fenestrated capillaries
• Fed by arteries in the stroma and drained by veins also in the stroma
• Between the capillaries, there are fine collagen fibres, fibroblasts and unmyelinated nerve fibres

Question 7

Bruch’s membrane

Answer 7

five layers

• basement membrane of choriocapillaris
• outer collagenous zone
• elastic layer
• inner collagenous zone
• basement membrane of RPE cells

Question 8

choroid blood supply

Answer 8

• supplied by branches of the circle of Haller- Zinn (branched from ophthalmic artery)
• Drainage is by the vorticose veins / vortex veins, then finally drain into superior & inferior ophthalmic veins.

Question 9

choroid nerve supply

Answer 9

short posterior ciliary nerves, which carries parasympathetic & sympathetic nerves