Anatomy

Question 1

Choroid

Answer 1

vascular layer between retina and sclera
BVs to nourish outer layers of retina
produce heat exchange from retina
conduct BVs to ant regions of eye
assists in IOP regulation
pigment cells absorb excess light penetrating retina - prevents reflection

Question 2

Posterior vitreous detachment

Answer 2

increase in age = decrease gel structure
and increase liquid volume
pulls away from retina
casts shadow on retina — seen as floaters

traction on retina - creates retinal tear and fluid seeps underneath retina = retinal detachment - seen as shower floater and curtains closing over eye
urgent referral
Cx of diabetic retinopathy

Question 3

Flow of aqueous

Answer 3

ciliary body 
posterior chamber 
pupil 
anterior chamber 
trabecular meshwork 
Schlemm's canal 
Episcleral venous system

Question 4

Ciliary body

Answer 4

Gives rise to zonules
Epithelium secretes aqueous
Ciliary muscle - accommodation of lens

Question 5

Supplied by SNS

Answer 5

Muller’s muscle
Dilator pupillae
Ciliary epithelium

Question 6

Supplied by PNS

Answer 6

Constrictor pupillae

Ciliary muscle

Question 7

Media of eye

Answer 7

cornea 
anterior chamber 
lens 
posterior chamber 
vitreous

Question 8

Components of urea

Answer 8

iris
ciliary body
choroid

Question 9

Myopia

Answer 9

short sightedness = corrected biconcave lenses

eyes look small through glasses

Question 10

Hypermetropia

Answer 10

far-sightedness = corrected biconvex lenses

eyes look big through glasses

Question 11

Presbyopia

Answer 11

age related loss of lens elasticity
cannot accommodate for near vision
needs reading glasses/bifocals

Question 12

Astigmatism

Answer 12

Light not evenly focused on retina

Question 13

Extra-ocular muscles functions

Answer 13

MR = adduction 
LR = abduction 
IO = extorsion 
SO = intorsion 
SR = elevation 
IR = depression

Question 14

SOF

Answer 14

superior ophthalmic vein
CN III, IV, VI and ophthalmic division of trigeminal
lacrimal frontal and nasociliary nerve

Question 15

IOF

Answer 15

maxillary division of trigeminal

inferior ophthalmic vein

Question 16

Optic canal

Answer 16

CN II and ophthalmic artery

Question 17

Layers of retina

Answer 17

Inner limiting membrane 
Neural fibre layer 
Ganglion cell layer 
Inner plexiform layer 
Inner nuclear layer 
Outer plexiform layer 
Outer nuclear layer 
External limiting membrane 
Photoreceptor layer 
Retinal pigmented epithelium

Question 18

Normal
Cup:Disc
AV ratio

Answer 18

4: 10
2: 3

Question 19

Ocular pathway

Answer 19

CNII 
optic chiasm 
optic tract 
LGB 
optic radiations 
visual cortex in occipital lobe

Question 20

Accommodation

Answer 20

lens becomes more globular
pupil constricts
eyes converge

Question 21

Levator palpebrae superioris

Answer 21

CN III

trauma = ptosis

Question 22

Rods vs Cones

Answer 22

Rods

• 1 type = black and white vision
• peripheral vision
• vision in dim light
• not present at fovea but present everywhere else
• slow response

Cones

• 3 types - colour vision
• central vision
• vision in bright light
• highest density at fovea and macula
• fast response