opthalmology

Question 1

What is the basic anatomy of the eye?

Answer 1

ANTERIOR
cornea, iris, lens, ciliary body

POSTERIOR
vitreous, retina, optic nerve

Question 2

What are the extra ocular muscles?

Answer 2

Superior rectus
Inferior rectus
Medial rectus
Lateral rectus

Superior oblique
Inferior oblique

Question 3

What can you see if you look at the back of the eye?

Answer 3

Optic nerve
Macula
Retina
Retinal vessels

Question 4

How does the eye work with the brain?

Answer 4

Retina converts light to electrical impulses
These travel through optic nerve
Processed in occipital cortex

Question 5

What is the visual pathway?

Answer 5

1. Temporal visual field falls on nasal retina, superior visual field falls on inferior retina

2. Decussation of nasal retinal fibres at optic chiasm

3. RHS of visual field represented on LHS of brain

Question 6

How might visual field defects indicate lesion locations?

Answer 6

Eg. Pituitary macroadenoma may squash optic chiasm leading to a bitemporal hemianopia

Question 7

How might stroke affect the eyes?

Answer 7

Can lose vision in one or both eyes- in one field
Eg. middle cerebral artery- homonomous hemianopia

BEFAST (balance, eyes, face, arms, speech, time)

Question 8

What are symptoms of visual disturbance?

Answer 8

Loss of vision
Diplopia
Ptosis (droopy lid)
Pain/headache
Flashing lights/floaters
Visual field defects
Pupil size inequality

Question 9

What are some causes of visual disturbance?

Answer 9

CATARACT- due to stroke, diabetic retinopathy
MACULAR DEGENERATION- due to inflam (optic neuritis in MS), vessel occlusions, atherosclerosis
GLAUCOMA- due to migraine, giant cell arteritis
RETINAL DETACHMENT- due to papilloedema, accelerated hypertension
EYE INFECTIONS

Question 10

When might infection cause red eye?

Answer 10

Eg. Conjunctivitis
Usually viral (watering), eg Adenovirus, but may be bacterial (purulent discharge)
Normal vision
Tx= lubricant drops, antibiotic if bacterial

Question 11

When might ulcer/abrasion cause red eye?

Answer 11

CORNEAL ABRASION-
V painful, due to trauma, 2-3 day heals

CORNEAL ULCER-
V painful, contact lenses, urgent referral to ophthalmologist as can scar cornea

Question 12

What problems can contact lenses cause?

Answer 12

Corneal ulcer
Fungal infection
Acanthamoeba

Question 13

When might subconjunctival haemorrhage cause red eye?

Answer 13

Bright red blood
Spontaneous/traumatic
Pt on anticoags/clotting problems?
Check blood pressure
2 weeks resolve

Question 14

When might anterior uveiitis cause red eye?

Answer 14

Inflam in front of eye
Pain, light sensitivity
Decreased vision
Irregular pupil
Linked to ankylosing spondylitis
Referral to ophthalmologist

Question 15

When might acute angle closure glaucoma cause red eye?

Answer 15

Fixed mid dilated pupil
Corneal oedema (cloudy)
High pressure in eye can be blinding (squashes optic nerve)
Older pts
V painful, N&V
Urgent referral

Question 16

When might scleritis cause red eye?

Answer 16

Inflam of sclera
Normal vision
Blue purple hue
Intense pain, keeps pt up at night
Urgent referral
Tx= steroid

Question 17

How might cataracts cause vision loss?

Answer 17

Opacity of lens
Due to ageing
Earlier due to diabetes, trauma, steroid use
Gradual loss of vision

Question 18

How might macular degeneration cause vision loss?

Answer 18

Age related
Dry- Drusen deposits in macular region
Wet- neovascular and fluid leakage
Loss of central vision or distortion

Question 19

How might retinal detachment cause vision loss?

Answer 19

Shadow in peripheral vision
Preceded by flashing lights/floaters
Retina detached from wall
Urgent referral

Question 20

How might CRAO cause vision loss?

Answer 20

Central retinal artery occlusion
Sudden irreversible loss
Usually embolus due to atherosclerosis
Urgent referral

Question 21

How might diabetic retinopathy cause vision loss?

Answer 21

Retinal vessels become leaky—> oedema
Retinal ischaemia and neovascularisation—> bleed
Non perfusion= blind spot

Question 22

How might chronic open angle glaucoma cause vision loss?

Answer 22

Painless w elevated eye pressure over prolonged time
Gradual field loss

Question 23

How might migraines affect vision?

Answer 23

Transient field defects 30 mins
Zig zag lights
Kaleidoscope effects

Question 24

How might giant cell arteritis affect vision?

Answer 24

Severe headache
Scalp/jaw pain
Tender temporal artery
Urgent
Can cause strokes/bilateral blindness

Question 25

How might papilloedema cause vision loss?

Answer 25

Raised intracranial pressure causes optic nerve swelling