What are the immediate steps to take if central retinal artery occlusion is suspected?

From the Guidelines

Immediate management of suspected central retinal artery occlusion (CRAO) requires rapid intervention to potentially salvage vision, with the most critical step being prompt referral to an ophthalmologist or emergency department within a time-sensitive window of approximately 90-120 minutes before permanent retinal damage occurs. The initial examination should include visual acuity, slit-lamp biomicroscopy, intraocular pressure, gonioscopy when neovascularization of the iris is present or suspected, relative afferent pupil defect assessment, and fundoscopy, as outlined in the retinal and ophthalmic artery occlusions preferred practice pattern 1.

While awaiting referral, several interventions can be attempted to dislodge the obstruction and improve retinal perfusion:

• Digital ocular massage by applying firm pressure to the eye through closed eyelids for 5-15 seconds, then releasing for 5 seconds, repeating for several minutes, as this can dislodge emboli and restore blood flow 1.
• Instructing the patient to breathe into a paper bag or administering carbogen (95% oxygen, 5% carbon dioxide) if available to induce vasodilation through hypercapnia.
• Administering high-flow oxygen via face mask at 10-15 L/min to increase oxygen delivery to the retina.
• Considering immediate anterior chamber paracentesis, where 0.1-0.2 mL of aqueous humor is removed using a 30-gauge needle at the limbus under topical anesthesia to lower intraocular pressure.
• Administering intravenous acetazolamide 500 mg to reduce intraocular pressure, as these interventions aim to create a pressure gradient that may help dislodge the obstruction and improve retinal perfusion.

It is essential to note that CRAO may indicate underlying cardiovascular disease, and prompt cardiovascular and neurological evaluation is crucial to prevent stroke or other vascular events, as highlighted in the management of central retinal artery occlusion: a scientific statement from the American Heart Association 1. Additionally, the risk factors for CRAO, including cigarette smoking, hypertension, high serum lipid levels, coagulopathy, body mass index, diabetes, and cardiac disease, should be considered in the management and follow-up of these patients 1.

Given the most recent and highest quality evidence, the immediate steps to take if central retinal artery occlusion is suspected should prioritize rapid referral and initial interventions aimed at dislodging the obstruction and improving retinal perfusion, with a focus on minimizing the time to treatment to preserve vision.

From the Research

Immediate Steps to Rule Out Central Retinal Artery Occlusion

To rule out central retinal artery occlusion (CRAO), several immediate steps can be taken:

• Conduct a thorough medical evaluation to identify any underlying systemic vascular disease 2
• Perform a comprehensive ophthalmologic examination, including fundus examination and optical coherence tomography (OCT) to observe increased hyperreflectivity of the inner retina 3
• Check for the presence of cherry-red spots, although their absence does not rule out CRAO 3
• Consider the patient's medical history and risk factors for CRAO, such as age, cardiovascular disease, and carotid artery disease 4, 2

Diagnostic Considerations

When diagnosing CRAO, consider the following:

• The clinical presentation of CRAO can vary, with some patients presenting with sudden, painless visual loss and others with more subtle symptoms 5
• The presence of posterior retinal whitening, leopard fundus, or retinal vein occlusion can affect the visibility of cherry-red spots 3
• OCT and fluorescein angiography (FA) can be useful diagnostic tools in detecting CRAO, even in the absence of cherry-red spots 3

Management and Referral

If CRAO is suspected, the following steps can be taken:

• Refer the patient to an ophthalmologist for immediate evaluation and treatment 4, 5
• Consider the use of emergency treatments, such as intravenous acetazolamide, digital ocular massage, and inhalation of 5% carbon dioxide -- 95% oxygen 5
• Initiate comprehensive medical evaluation to exclude systemic vascular disease and identify potential risk factors for CRAO 5, 2