Table 1.

Suggested history and investigations for patients with central retinal artery occlusion

Arteritic cause	Investigation
History to investigate common risk factors	Family history of cardiovascular and cerebrovascular diseases
	Diabetes mellitus
	Dyslipidemia
	Valvular heart disease
	Smoking
	Past medical history of TIAs or angina
Blood investigations for common vascular risk factors	Blood pressure
	Fasting blood glucose level
	Fasting cholesterol levels
Investigations to identify if it is from an embolic source	Duplex carotid ultrasound
	Echocardiogram
Investigations for young patients (<50 years) with no vascular risk factors	Hypercoagulable screen (protein C and S, factor V Leiden, antiphospholipid antibody)
	Vasculitic screen (ANA, ENA, ANCA, ACE)
	Myeloproliferative or sickle cell disease (blood film)

TIA: Transient ischemic attack, ANA: Antinuclear antibody, ENA: Extractable nuclear antigen, ANCA: Antineutrophil cytoplasmic antibody, ACE: Angiotensin-converting enzyme