sudden loss of vision

Question 1

what is transient monocular visual loss?

Answer 1

a sudden, transient loss of vision that lasts less than 24 hours

Question 2

what are the most common causes of a sudden painless loss of vision?

Answer 2

ischaemic/vascular (e.g. thrombosis, embolism, temporal arteritis etc). This includes recognised syndromes e.g. occlusion of central retinal vein and occlusion of central retinal artery

vitreous haemorrhage

retinal detachment

retinal migraine

Question 3

what are ischaemic/vascular causes of sudden vision loss?

Answer 3

often referred to as ‘amaurosis fugax’

wide differential including large artery disease (atherothrombosis, embolus, dissection), small artery occlusive disease (anterior ischemic optic neuropathy, vasculitis e.g. temporal arteritis), venous disease and hypoperfusion

may represent a form of transient ischaemic attack (TIA). It should therefore be treated in a similar fashion, with aspirin 300mg being given

altitudinal field defects are often seen: ‘curtain coming down’

ischaemic optic neuropathy is due to occlusion of the short posterior ciliary arteries, causing damage to the optic nerve

Question 4

what is the epidemiology of central retinal vein occlusion?

Answer 4

incidence increases with age, more common than arterial occlusion

Question 5

CRVO causes?

Answer 5

glaucoma, polycythaemia, hypertension

Question 6

CRVO on fundoscopy?

Answer 6

severe retinal haemorrhages are usually seen on fundoscopy

Question 7

causes of central retinal artery occlusion?

Answer 7

due to thromboembolism (from atherosclerosis) or arteritis (e.g. temporal arteritis)

Question 8

features of central retinal artery occlusion?

Answer 8

features include afferent pupillary defect, ‘cherry red’ spot on a pale retina

Question 9

causes of vitreous haemorrhage?

Answer 9

diabetes, bleeding disorders, anticoagulants

Question 10

features of vitreous haemorrhage?

Answer 10

features may include sudden visual loss, dark spots

Question 11

what are features of retinal detachment?

Answer 11

features of vitreous detachment, which may precede retinal detachment, include flashes of light or floaters

Question 12

features of posterior vitreous detachment?

Answer 12

Flashes of light (photopsia) - in the peripheral field of vision
Floaters, often on the temporal side of the central vision

Question 13

features of retinal detachment?

Answer 13

Dense shadow that starts peripherally progresses towards the central vision
A veil or curtain over the field of vision
Straight lines appear curved
Central visual loss

Question 14

features of vitreous haemorrhage?

Answer 14

Large bleeds cause sudden visual loss
Moderate bleeds may be described as numerous dark spots
Small bleeds may cause floaters