Visual Loss Summary

Emergency Conditions

CRAO: Ocular stroke (100 min window)
GCA: Bilateral blindness risk
Retinal detachment: Surgical emergency
Ischemic optic neuropathy: Urgent steroids if GCA

Key Findings

RAPD: CRAO, optic neuritis, retinal detachment
Cherry red spot: CRAO
Stormy sunset: Retinal vein occlusion
Floaters + flashes: Retinal detachment

Age Associations

Young (20-40): Optic neuritis
Middle-aged: Retinal detachment, vein occlusion
Elderly (>50): GCA, AMD, CRAO

Management Priorities

Rule out GCA in >50 years
CRAO: Treat within 100 minutes
Retinal detachment: Urgent referral
Optic neuritis: Neurology referral

Critical Investigations

ESR/CRP (GCA screen)
Blood pressure
Blood glucose
Carotid ultrasound if embolic

Red Flags

Bilateral symptoms
Jaw claudication + headache
Neurological symptoms
Pain with eye movement

SUDDEN (PAINLESS) VISUAL LOSS

Comprehensive guide to diagnosis, clinical features, and emergency management

Overview

Sudden painless visual loss represents an ophthalmic emergency requiring prompt evaluation and management. This guide covers the major causes, their distinguishing features, and emergency management priorities.

Emergency Priorities: Always rule out giant cell arteritis in patients over 50, and remember that CRAO has a 100-minute treatment window for potential visual recovery.

Differential Diagnosis Table

Diagnosis	Predisposing Factors	Clinical Features	Fundoscopic Findings
Retinal Detachment	Advancing age Myopia Post-cataract surgery Trauma Intraocular disease Diabetes mellitus	4Fs: Floaters, flashing lights, field defects and a fall in acuity Classically 'Curtain falling down over vision' Detachment of macula results in central vision loss Relative afferent pupillary defect	Absent red reflex Grey opalescent retina ballooning forward Normal examination does not exclude diagnosis
Vitreous Haemorrhage	Diabetic retinopathy Retinal detachment Posterior vitreous detachment Trauma Age-related macular detachment	Sudden painless loss of vision; can vary from haziness of vision with blind spots or dark streaks to complete visual loss Vitreous floaters	Absent red reflex RBCs or blood clots in anterior vitreous The retina is not seen on fundoscopy in large bleeds
Central Retinal Artery Occlusion (CRAO)	Older patients (> 60 yrs) Arteriopathy Giant cell arteritis Vasculitis Thrombophilia Hyperviscosity states	Sudden painless visual loss (to finger counting or no light perception) Relative afferent pupillary defect occurs early	Retina appears pale with a cherry red spot at the macula Retinal emboli may be visible
Retinal Vein Occlusion	Advancing age Arteriosclerosis Hypertension Diabetes Hyperviscosity states Chronic glaucoma	Sudden painless visual loss (usually to finger counting) with field defects Afferent pupillary defect only if ischaemic changes in central retinal vein	'Stormy sunset' appearance Hyperaemic retina with tortuous dilated vessels Optic disc swelling Retinal haemorrhages Cotton-wool spots
Anterior Ischaemic Optic Neuropathy (GCA)	Patient > 50 yrs	Sudden loss of vision Often starts unilateral and becomes bilateral Associated with: temporal headache, temporal artery abnormality, scalp tenderness, jaw claudication, systemic features, features of polymyalgia rheumatica	Pale swollen optic disc Cotton-wool patches Retinal haemorrhages
Optic Neuritis	Women aged 20 - 40 years May be first presentation of MS	Subacute loss of vision occurs over hours or days (usually central) Dyschromatopsia (with red desaturation) Painful eye movements Relative afferent pupillary defect	Optic disc on fundoscopy may appear normal, or may be swollen and/or haemorrhagic
Posterior Vitreous Detachment	Advancing age Normal physiological process	Sudden onset of floaters with flashing lights Visual acuity usually normal; if acuity affected then consider associated retinal detachment	Usually normal
Wet Age-related Macular Degeneration	Advancing age	Sudden distortion Decreased visual acuity with central scotoma Peripheral vision remains normal	Drusen – yellow fatty deposits lipid under the retina Subretinal haemorrhages Hard exudates – appear white Macular oedema
Amaurosis Fugax	Arteriopathy - risk factors for TIA	Temporary painless loss of vision in one eye 'like a curtain coming down' with complete recovery typically within 60 minutes May be associated with signs of cerebral ischaemia	Usually normal

Emergency Management Guide

Time-Critical Conditions

CRAO: 100-minute treatment window
GCA: Immediate high-dose steroids to prevent bilateral blindness
Retinal detachment: Urgent surgical referral

Urgent Referrals

Optic neuritis: Neurology referral for MS workup
Retinal vein occlusion: Ophthalmology referral
Wet AMD: Urgent ophthalmology assessment

Non-urgent Conditions

Posterior vitreous detachment: Routine follow-up
Amaurosis fugax: TIA workup and secondary prevention

Initial Assessment Protocol

Emergency Department Approach

Visual acuity assessment in both eyes
Pupillary examination for RAPD
Visual field testing to confrontation
Ocular motility and pain with movement
Red reflex assessment
Fundoscopy if possible
Systemic review for GCA symptoms in >50 years
Neurological examination if indicated

Key Diagnostic Clues

By Age Group

20-40 years: Optic neuritis (especially women)
40-60 years: Retinal detachment, vein occlusion
>50 years: GCA (urgent exclusion required)
>60 years: CRAO, AMD

By Symptom Pattern

Floaters + flashes: Retinal detachment/PVD
Pain with eye movement: Optic neuritis
Transient loss: Amaurosis fugax
Central scotoma: Optic neuritis, AMD
Altitudinal defect: Ischemic optic neuropathy

Critical Investigations

Condition	Essential Investigations
GCA Suspected	ESR, CRP, temporal artery biopsy
CRAO	Carotid Doppler, echocardiogram, ECG, hypertension/diabetes workup
Optic Neuritis	MRI brain/orbits, neurology referral
Amaurosis Fugax	Carotid imaging, cardiac monitoring, TIA workup
Retinal Vein Occlusion	Blood pressure, glucose, lipid profile

Special Considerations

Giant Cell Arteritis (GCA) - Ophthalmic Emergency

Most common cause of permanent bilateral blindness in elderly
Start high-dose steroids immediately if clinical suspicion
Do not wait for ESR/CRP results to initiate treatment
Typical dose: Prednisolone 1mg/kg/day
Urgent ophthalmology and rheumatology referral

Central Retinal Artery Occlusion (CRAO)

Considered an ocular stroke
Irreversible damage after 100 minutes
Emergency measures: ocular massage, acetazolamide, anterior chamber paracentesis
High risk of subsequent cerebral stroke - requires comprehensive workup

Optic Neuritis and Multiple Sclerosis

30-50% of optic neuritis patients develop MS
MRI brain important for prognosis and treatment decisions
IV steroids may speed recovery but don't affect long-term vision
Neurology referral essential