Ophthalmologists from the New York Eye and Ear Infirmary of Mount Sinai (NYEE) have created a new protocol to rapidly diagnose retinal artery occlusion, also known as eye stroke, to prevent irreversible vision loss.
The study, published online in Ophthalmology, 1 describes using high-resolution retinal imaging in the emergency room, along with rapid remote consultation to confirm diagnosis and expedite care.
“The protocol implements highly sensitive retinal imaging at the patient’s point of entry into the medical system, reducing the need for onsite ophthalmology consults, which are often not immediately available,” said study author Dr Richard B. Rosen, Chief of the Retina Service for the Mount Sinai Health System.
“Seamless cooperation and coordination between the subspecialty teams of stroke neurologists, retinal specialists, and interventional radiologists is the key to rapid triage of these emergency patients.
“This model can easily be implemented anywhere in the country where a stroke team is available.”
TWELVE HOUR WINDOW
Painless, sudden vision loss in one eye may be a sign of central retinal artery occlusion. It happens when the main artery that supplies blood to the retina is blocked, typically by a clot, depriving the retina of oxygen. It is similar to a stroke in the brain.
The clot needs to be dissolved as soon as possible, ideally within six to 12 hours of losing vision, or it will lead to permanent vision loss.
Mount Sinai’s Department of Ophthalmology’s Eye Stroke Service has led to high-tech eye imaging devices using optical coherence tomography (OCT) being placed in three hospitals within the Mount Sinai health system that have large emergency rooms and stroke teams.
When a patient arrives at the emergency room with possible retinal artery occlusion, the stroke service evaluates and scans the patient, electronically sending the images to remote on-call retinal specialists who can make an instant diagnosis.
If the retinal specialist confirms an eye stroke diagnosis, the vascular interventional neuroradiologists can dissolve the clot with an infusion of tissue plasminogen activator (tPA) – a clot-dissolving drug – into the blocked ophthalmic artery.
PROTOCOL RESULTS
Researchers analysed 59 patients who went through the protocol in the first 18 months since the launch of the Eye Stroke Service.
The average time to treatment after the patients arrived at the hospital was roughly two and a half hours. Patients were treated, on average, about nine hours from the onset of symptoms, which included the time the patients took to come to the hospital.
Twenty-five patients (42%) had a confirmed eye stroke, 10 patients were eligible for treatment, and nine received treatment with intra-arterial tPA. There was a statistically significant improvement in their visual acuity four weeks after treatment.
Researchers noted a dramatic improvement in 66% of these patients within 24 hours of treatment, with 56% of treated patients maintaining improved vision one month following the procedure.
On average, the patients’ vision improved dramatically – from ‘counts fingers’ to 20/100. Four patients (44% of those treated with tPA) improved to 20/40 or better, which constitutes unrestricted driving vision in New York State.
Dr Gareth Lema, lead author of the study, said the “importance of education among the medical community and the public cannot be stressed enough”.
“Patients with an eye stroke are at risk of also developing a stroke in the brain, and that risk is highest in the first month after diagnosis.
“If patients get to us in time, we can treat. But even for those who don’t, the systemic work up to identify the source of the stroke might be even more critical,” Dr Lema said.
Reference
- Gareth M.C., Lema, G.M.C., De Leacy, R., Fara, M.G., et al., A remote consult retinal artery occlusion diagnostic protocol, Ophthalmology, published online 13 Feb 2024. DOI:10.1016/j. ophtha.2023.11.031.
