Retinal Artery Occlusion: A Stroke of the Eye

Last updated: October 2026

Central retinal artery occlusion (CRAO) is now understood as a stroke of the eye: it needs same-day stroke work-up. Thrombolysis has been tested, but randomised trials so far have not shown visual benefit.

Why "stroke of the eye" is the right framing

CRAO shares the same embolic/thrombotic pathophysiology as ischaemic cerebral stroke, and increasingly the same systemic workup and urgency — but historically, ophthalmology and stroke neurology have managed it quite differently, and current guidelines push toward unifying the approach.

The critical time window

Duration of retinal ischaemia correlates directly with ganglion cell loss, with 240 minutes (4 hours) cited as the cutoff beyond which massive, irreversible retinal damage is expected — closely mirroring the ~4.5-hour window used in cerebral stroke thrombolysis protocols. This is why CRAO is a true same-hour emergency, not a "see when convenient" ophthalmology referral.

Thrombolysis: tested in trials, not proven

This is an active, evolving area rather than settled practice:

• Multiple observational studies and meta-analyses of IV tissue plasminogen activator (tPA) in CRAO presenting within 4.5 hours have shown a strong positive signal for visual recovery
• Several randomized controlled trials have been conducted to test this properly: THEIA (IV alteplase vs oral aspirin within 4.5 hours; Lancet Neurology, November 2025) found no significant difference in visual recovery, though it was probably underpowered. TenCRAOS (IV tenecteplase vs aspirin; NEJM, January 2026) also found no visual benefit and had more serious adverse events, including one fatal intracerebral haemorrhage. REVISION is still to report in full
• A 2022 survey of German stroke units found real-world practice already quite heterogeneous: roughly 57% of responding centres performed thrombolysis for CRAO despite the absence of definitive RCT-level guidance at that time — reflecting genuine clinical uncertainty translated into variable practice
• Practical implication for residents: know that observational data looked promising, but the two randomised trials reported so far (THEIA and TenCRAOS) did not show benefit, so thrombolysis for CRAO is not standard care and should be given only within a trial or a local stroke protocol — practice varies significantly by centre and country

A real safety concern with thrombolysis

Case reports describe intraocular haemorrhage following intravenous thrombolysis given for a misdiagnosed CRAO — underscoring that accurate diagnosis before treatment matters enormously, since thrombolysis carries real bleeding risk that isn't justified if the underlying diagnosis turns out to be wrong.

Current diagnostic and triage approach

• Painless, sudden monocular vision loss is the classic presentation — treat as a stroke-equivalent emergency requiring same-day, ideally same-hour, evaluation
• The AAO's 2024 Preferred Practice Pattern for Retinal and Ophthalmic Artery Occlusions now frames CRAO explicitly within a stroke-care pathway
• Point-of-care ultrasound and OCT are increasingly used as emerging bedside diagnostic adjuncts alongside traditional fundus examination
• Given the shared embolic mechanism with cerebral stroke, urgent same-day stroke workup is now standard: carotid imaging, cardiac evaluation (echocardiogram, telemetry for atrial fibrillation), and standard vascular risk factor assessment — a CRAO diagnosis should trigger the same systemic urgency as a TIA, not just an ophthalmology-only response
• Telemedicine-enabled thrombolysis pathways are emerging in some centres specifically to reduce the time from symptom onset to potential treatment

Older treatments: limited evidence

Ocular massage, anterior chamber paracentesis, and hyperbaric oxygen have all been historically described, but none has robust evidence supporting a meaningful effect on visual outcome — they should not be relied upon as definitive treatment, and shouldn't delay the systemic stroke workup that matters more.

Key references: AAO. Retinal and Ophthalmic Artery Occlusions PPP, 2024.  |  Central retinal artery occlusion: a stroke of the eye. Eye. 2024.  |  Treatment of acute CRAO: light at the end of the tunnel? Lancet Neurol. 2025.