Sudden Loss of Vision

Question 1

Causes of sudden loss of vision

Answer 1

Acute glaucoma
Anterior ischaemic optic neuropathy
Optic neuritis
Vitreous haemorrhage
Retinal detachment
Retinal artery occlusion
Retinal vein occlusion

Question 2

Aetiology anterior ischaemic optic neuropathy

Answer 2

Inflammation or atheroma → Posterior ciliary artery blockage → optic nerve damage

Arteritic: giant cell arteritis
Non-arteritic: DM, HTN, hypercholesterolaemia, smoking

Question 3

Symptoms and signs of anterior ischaemic optic neuropathy

Answer 3

Sudden visual loss
RAPD
Visual field defectsI

Question 4

Investigations for anterior ischaemic optic neuropathy

Answer 4

Fundoscopy: pale, swollen optic disk, peripheral microaneurysms
ESR: differentiate between arteritic and non-arteritic

Question 5

Management for anterior ischaemic optic neuropathy

Answer 5

GCA → high dose IV methylprednisolone

Question 6

Symptoms and signs of optic neuritis

Answer 6

Colour vision affected → red desaturation
Central scotoma
Relative afferent pupillary defect
Acuity reduced
Painful eye movements
Field defects

Question 7

Aetiology optic neuritis

Answer 7

MS
DM
Drugs e.g. ethambutol, chloramphenicol
Infection e.g. VZV, lyme, syphilis

Question 8

Investigations for optic neuritis

Answer 8

Fundoscopy: swollen optic disc
MRI brain and orbits with gadolinium contrast
- if > 3 white-matter lesions, 5-year risk of developing multiple sclerosis is c. 50%

Question 9

Management for optic neuritis

Answer 9

IV methylprednisolone 72h
Prednisolone PO for 11 days

Question 10

Aetiology of vitreous haemorrhage

Answer 10

Bleeding into the vitreous humour, with source being from any vessel in the retina + extension through the retina
Bleeding stops → blood clears from the retina 1% a day

DM proliferative retinopathy → angiogenesis (50%)
Retinal tear
Retinal detachment
Trauma
Warfarin use

Question 11

Symptoms and signs of vitreous haemorrhage

Answer 11

One of the most common causes of PAINLESS visual loss

Small bleed → small black dots seen, ring floaters, red hue
Large:
- loss of red reflex
- retina cannot be visualised
- decreased visual acuity
Severe → visual field defect

Question 12

Investigations for vitreous haemorrhage

Answer 12

Dilated fundoscopy: haemorrhage in the vitreous cavity
Slit lamp: RBCs in the anterior vitreous
B-scan (Brightness scan)
Ultrasonography: rule out retinal tear/detachment
Fluorescein angiography: identify neovascularisation
Open globe injury → orbital CT

Question 13

Management for vitreous haemorrhage

Answer 13

Smaller → will spontaneously reabsorb
Larger → vitrectomy

Question 14

Aetiology retinal detachment

Answer 14

Holes/tears in the retina allow fluid to separate the retina from the pigmented epithelium

Question 15

Aetiology retinal detachment

Answer 15

Cataract surgery
Trauma
Diabetes mellitus (breaks in the retina from traction by vitreous humour)
Myopia

Question 16

Symptoms and signs of retinal detachment

Answer 16

Floaters (numerous, acute-onset, spider webs)
Flashes
Field loss: “Veil/curtain falling down”
Reduced acuity (macula involvement → central visual acuity worsens → can only seen hand movements → RAPD)
Nerve involvement

Usually painless

Question 17

Investigations for retinal detachment

Answer 17

(fundoscopy) → loss of red reflex, grey, opalescent retina, ballooning forwards
Slit lamp
Indirect ophthalmoscopy
US

Question 18

Management for retinal detachment

Answer 18

24h referral to ophthal → urgent surgery (vitrectomy + gas tamponade with laser coagulation)