1 - Opth - Introduction and Anatomy - Middle (uveal) layer)

Question 1

Name the 4 parts of the middle eye

Answer 1

ciliary body, iris, choroid, postremal (vitreous) chamber

Question 2

Ciliary body - continuous with? attached to?

Contains? Type? Innervation? Two types of fibre?

Answer 2

continuous with choroid posteriorly and attached to iris and scleral spur anteriorly
contains ciliary muscle - smooth mm - innervated by parasym fibres from oculomotor nerve (|||)
Circular (pars plicata) and Longitudinal (pars plana) fibres

Question 3

Circular and Longitudinal fibres of ciliary body do what?

Answer 3

circ - plicata - contraction-> ciliary thickening towards centre of eye, relaxing zonule, controlling accommodation (near vision)

long - plana - contraction-> opens trab meshwork, humor drainage into canal of schlemm - used as surgical entry point)

Question 4

Iris - projects where?from? contains?

Answer 4

projects out from ciliary body
vascular and pigmented
SM fibres…
–Sphincter pupillae - constricts pupil - PS fibres from Oculomotor nerve
–Dilator pupillae - dilates pupil - S fibres from superior cervical ganglion T1

Question 5

Choroid - meshwork of? Directly supplies..? separated from RPE by?
contains? Blood supply?

Answer 5

meshwork of blood vessels with capillaries on internal layer (choriocapillaris)
directly supplies outer layers of retina and RPE
Bruch’s membrane separates it from RPE- preventing retinal oedema
contains pigmenting melanin
Blood supply - posterior ciliary arteries

Question 6

Postremal vitreous chamber - contains? what is this and whats its Fx?

Answer 6

contains vitreous humor - gel like substance - network of collagen fibres - filled with polymerised hyaluronic acid molecules
99% water
does not normally flow, aqueous may enter as age increases, parts may fall apart > floaters