opthalmology

Question 1

which part of the eye produces aqueous humour

Answer 1

cilliary body

Question 2

which cranial nerve palsy makes the eye go down and out when looking forward

Answer 2

oculomotor (cn3)

Question 3

which cranial nerve palsy makes the eye turn upwards and inwards when looking forward

Answer 3

trochlear (cn4)

Question 4

which cranial nerve palsy makes the eye turn inwards when looking forward

Answer 4

abducens (cn6)

Question 5

where abouts is the angle that gets blocked in acute angle closure glaucoma

Answer 5

where the trabecular meshwork is where the iris meets the cornea in the anterior chamber

Question 6

what is the function of the aqueous humour

Answer 6

to nourish an hydrate the eye

Question 7

where is the anterior chamber located

Answer 7

between the cornea and the iris

Question 8

where is the posterior chamber located

Answer 8

between the iris and the lens

Question 9

where is the viterous chamber located

Answer 9

behind the lens

Question 10

what is the function of the choroid

Answer 10

essentially a spongey vascular layer that helps to provide nutrients to the outer layer of the retina and contains pigment to absorb excess light

Question 11

what is the function of cilliary body

Answer 11

pupillary constriction / dilatation

produces aqueous humour

Question 12

what is the function of the lens

Answer 12

to focus (refract) light from the pupil onto the retina

Question 13

what is the function of the conjunctiva

Answer 13

a moist clear membrane that covers the sclera, it protects and lubricates the eye ball

Question 14

where are most cone cells found

Answer 14

fovea

Question 15

what is the function of the fovea and where is it found

Answer 15

found at the centre of the macula, produces a highly focused quality image to send to the brain

Question 16

what is the function of the iris

Answer 16

to control the amount of light that is able to enter the eye

Question 17

function of cone cells

Answer 17

colour vision
better in high light levels
high spatial acuity

Question 18

function of rod cells

Answer 18

night vision
better in low light levels
low spatial acuity

Question 19

pathophysiology of primary open angle glaucoma

Answer 19

slowly increasing resistance of trabecular meshwork to outflow of humour = gradually increasing IOP over time = asymptomatic for ages / fluctuating onset of symptoms

Question 20

symptoms of primary open angle glaucoma

Answer 20

asymptomatic / incidental finding by optometist
gradual loss of peripheral vision
nasal scotomas / tunnel vision
halos around lights at night 
fluctuating pain (not always)
headache

Question 21

findings on fundoscopy in primary open angle glaucoma

Answer 21

optic disc cupping - meaning the indent in the optic disc (optic cup) is more than 0.7
pale optic disc from optic atrophy

Question 22

investigations to do in suspected primary open angle glaucoma

Answer 22

1. fundoscopy
2. assess visual fields with automated perimetry
3. use slit lamp and dilate pupil to look for signs of optic nerve damage and assess baseline
4. goldmann applanation tonometry to assess intra ocular pressure

Question 23

1st line treatment of primary open angle glaucoma

Answer 23

latanoprost drops - prostaglandin analogue to increase uveosacral outflow

Question 24

how does timolol drops work

Answer 24

beta blocker - decreases production of aqueous

Question 25

how does latanoprost drops work

Answer 25

increases uveosacral outflow

Question 26

how does pilocarpine drops work

Answer 26

antimuscarinic that acts on the parasympathetic fibres to induce pupillary muscle constriction = pain relief and opens the angle to allow some drainage of humour

Question 27

how does oral / iv Acetazolamide work

Answer 27

reduces aqueous production by inhibiting carbonic anhydrase

Question 28

what investigations should you do in suspected acute angle closure glaucoma

Answer 28

1. goinoscopy - examines the anterior chamber angle 2. slit lamp examination 3. applanation tonometry to measure IOP

Question 29

findings on examination in acute angle closure glaucoma

Answer 29

hard, red eye fixed dilated non reactive pupil corneal oedema

Question 30

what should you give someone in the primary care setting pre-hospital with suspected acute angle closure glaucoma

Answer 30

1. pilocarpine eye drops 2% if blue eyes 4% if brown eyes 2. acetazolamide 500mg po stat 3. antiemetic + analgesia

Question 31

presentation of acute angle closure glaucoma

Answer 31

``` severely painful, red, hard eye haloes around lights worse in dark reduced visual acuity (blurred vision) semi dilated non reacting pupil corneal oedema - dull / hazy N+V ```

Question 32

which drugs can precipitate acute angle closure

Answer 32

anticholinergics eg oxybutinin | pupil dilating eye drops eg atropine

Question 33

what is seen on fundoscopy in both types of ARMD

Answer 33

drusen (yellow spots of lipids on the retina)

Question 34

pathophysiology in ARMD

Answer 34

both: drusen formation from lipid deposits and degeneration of retinal photoreceptors wet: get neovascularisation causing new vessels to leak fluid or haemorrhage into the retina causing retinal oedema = faster degeneration of vision

Question 35

describe the vision loss in ARMD

Answer 35

central scotoma / slow central loss of vision / loss of visual acuity of up close things / deterioration in night vision

Question 36

symptoms of ARMD

Answer 36

central scotoma, declining night vision, distortion of straight lines, seeing things flickering / flashing lights

Question 37

loss of peripheral vision and haloes around lights

Answer 37

acute glaucoma

Question 38

loss of central vision / central scotoma and blurring / waving of lines

Answer 38

ARMD

Question 39

generalised reduction in visual acuity and starbursts around lights at night time

Answer 39

cataracts

Question 40

key sign on examination in cataracts

Answer 40

loss of red reflex - will be white or grey instead

Question 41

symptoms of cataracts

Answer 41

reduced visual acuity things may go yellowy or brown in colour starbusts around lights at night asymmetrical as both lenses affected differently

Question 42

treatment of cataracts

Answer 42

if not an issue then leave it alone | if reduced visual acuity severe then surgery

Question 43

findings on fundoscopy in cataracts

Answer 43

normal

Question 44

complications following cataracts surgery

Answer 44

1. posterior capsule opacification 2. retinal detachment 3. endopthalmitis --> inflammation of aqueous and / or viterous humour

Question 45

name a cause of endopthalmitis

Answer 45

complication of cataracts surgery