sudden visual loss

Question 1

pathophysio of wet macular degeneration

Answer 1

vasculat proliferation - new vessels grow from choroid layer into retina
–> these leak fluid or blood + cause odema + more rapid loss of vision

Question 2

what stimulates the grow of new vessels in wet macular degeneration

Answer 2

vascular endothelial growth factor (VEGF)

Question 3

virchows triad - risk of venous thrombosis

Answer 3

endothelial damage
abnormal blood flow
hypercoaguble state

Question 4

retinal vein occlusion on fundoscopy

Answer 4

flame + blot haemorrhages
dilated tortuous veins
optic disc macula
macula oedea
disc swelling

Question 5

central retinal artery branches from where

Answer 5

branch of ophthalmic –> branch of internal carotid

Question 6

causes of central retinal artery occlusion

Answer 6

atherosclerosis

giant cell arteritis - old women, polymyalgia rheumatica
–> vasculitis affecting ophthalmis/central RA causes reduced blood flow

Question 7

presentation of central retinal atrtery occlusion

Answer 7

pale retina
cherry red spot
afferent pupillary defect - constricts more when shone in other eye

Question 8

amaurosis fugax

Answer 8

transient CRAO

transient painless visual loss, lasts 5mins
like a curtain coming down
usually nothing to see on exam

Question 9

treatment of CRAO

Answer 9

if giant cell arteritis suspected

• ESR + temporal artery biopsy
• steroids

Question 10

which arteries are the cause of ischaemic optic neuropathy

Answer 10

posterior ciliary arteries become occluded resulting in infarction of optic nerve head

swollen optic disc

Question 11

vitreous haemorrhage

Answer 11

bleeding into vitreous humour
large - sudden visual loss
small - floaters

loss of red reflex

Question 12

posterior vitreous detachment

Answer 12

where vitreous gel comes away from the retina

very common, esp in older

(can predispose retinal detachment)

Question 13

posterior vitreous detachment presentation

Answer 13

flashes of light (photopsia) in peripheral field of vision
floaters

(no treatment, brain will adjust + improve symptoms)

Question 14

retinal detachment

Answer 14

where retina separates from choroid underneath - usually due to retina tears that lets in vitreous fluid + fills space between

(may be preceded by posterior vitreous detachment)

Question 15

why is retinal detachment sight threatening?

Answer 15

retina relies on blood vessels of the choroid for its blood supply

Question 16

retinal detachment presentation

Answer 16

dense shadow that start peripherally progresses towards central vision
–> like a veil or curtain of visual field

floater