Sudden visual loss

Headline
History ➥ duration, permanent/transient, progression
➥ where affected: degree, central/peripheral
➥ distribution (unilat/bilat), painful (anterior cause)
➥ Associated s/s: Headache, ophthalmoplegia, flashers/floaters
➥ Risk factors: AF, bleeding disorders, Poorly controlled DM, Amaurosis fugax
➥ DHx: methanol, quinine (in overdose)
Examination General inspection - outer to inner, surface to deep
➥ eyelid, eyelashes, conjunctiva, corneal opacities, foreign bodies
➥ corneal reflex - will be blunted by local anaesthetic!
➥ Acuity - Snellen chart (can print off), pt wearing glasses if they usually wear
➥ Colour vision - use red object if no Ishihara plates
➥ Fundoscopy - most important in non-ophthal setting is to check optic disk
-- optimise: dark room, pt to fixate on a faraway spot
-- Document what you try
Diagnostic investigations See fundoscopy findings below.
Differentials ➥ embolic: amaurosis fugax, CRAO
➥ CRVO (central retinal vein occlusion) - sudden, painless, unilateral
➥ Ischaemic optic neuropathy
➥ vitreous haemorrhage
➥ optic neuritis
➥ fat embolus - in trauma context
➥ retinal detachment: sudden painless, progressive visual field loss with new floaters/flashers
Immediate management ➥ CRAO: treat like stroke with risk factor management; possible role for ocular massage?!
➥ See Acute closed-angle glaucoma
➥ Temporal arteritis: 60mg prednisolone and arrange temporal artery biopsy
➥ retinal detachment: same day ophthal r/v if any sight-threatening disease
Ongoing management CRVO: control risk factors +/- vasculitis/hypercoagulability workup
Retinal detachment: laser/cryotherapy; inform DVLA; vitrectomy

fundoscopy findings

because we're all experts at fundoscopy.

Retinal detachment Absent red reflex
May be normal
Central retinal vein occlusion 'Stormy sunset'
Tortuous dilated vessels
Optic disc swelling
Retinal haemorrhages
Cotton wool spots
Central retinal artery occlusion Pale retina
Cherry red spot at macula
Vitreous haemorrhage Large bleeds - retina not visible
Giant cell arteritis → ischaemic optic neuropathy Pale swollen optic disc
Cotton wool patches
Wet macular degeneration Drusen
Macular oedema
Hard exudate
Subretinal haemorrhages