Ocular Circulation Flashcards
What’s the principle function of the choroid?
To nourish the outer 1/3 of the retina
What are the other functions of the Choroid?
Absorb excess light from RPE, contribute to Bruch’s membrane, provide protective canal for vessels and nerves (suprachroidal space), stabilizes ocular temperature
What are the 3 layers of vessels in the choroid?
Choriocapillaris (inner), Sattler’s Layer (middle), Haller’s Layer (outer)
What size are the vessels of the choriocapillaris? What type of vessels are they?
- small (40-60microns)
- fenestrated
What size are the vessel of Sattler’s Layer? What type of vessels are they?
- medium vessels
- nonfenestrated Vessels
What size are the vessels of Haller’s layer? Where can we find this layer?
- large vessels
- Part of choroidal stroma
What can we find in Haller’s Layer?
The 4 vortex veins
What are the main functions choriocapillaris?
Supplies nutrients and blood, removes waste from outer retina and macular region.. has a relationship with RPE and Bruch’s membrane
How many layers are found in the choriocapillaris region?
Single layer of broad capillaries
The choriocapillaris is internal to ______ layer and external to _____ _____.
Sattler’s Layer, bruch’s membrane
Which layer contains the largest capilalries of the eye and allows passae of multiple RBCs without damage?
Choriocapillaris
What are the 3 sources of chroidal blood supply?
Short cililary arteries, long ciliary arteries and anterior ciliary arteries
The posterior pole develops the _____
ora serrata
What is the gradient of development for the layers of the choroid?
Choriocapillaris develops first»_space; Sattlers Layer»_space; Hallers Layer
RPE induces _____ in the choroid.
angiogenesis
Development of choroidal vasculature depends on what?
The presence of differentiated RPE and production of inductive signals
Neural Ectoderm develops into?
Basement membrane of RPE which secretes bruch’s membrane
Mesodermal Mesenchyme develops what?
Endothelium of BV and Blood elements of the choroid
Neural Crest develops what?
Melanocytes, Fibrocytes and smooth muscle of blood vessles
Hard drusen are found what kind of RPE?
Thinned but Intact RPE
What are the generalizations of Soft Drusen?
- localized RPE detachments
- More likely to have vision loss
- High risk for Wet ARMD
Angioid Streaks represent breaks where? What are the other generalizations?
In bruch’s membrane
There will be radiating lines from optic disc (looks like a cracked sidewalk)
Possible choroidal neovascularization
The choroid supplies the _____ of the retina, and the CRA supplies the _____ of the retina
Choroid = outer 1/3 Retina = Inner 2/3
The Central Retinal System has and inner capillary plexus that is found in what layer? What is another name for this plexus?
Ganglion Cell Layer
Superficial Capillary Plexus
