The application of a retinal stroke coding protocol improves visual recovery in patients receiving reperfusion therapies

• Named 'Retina Stroke Code', it acts against a type of stroke that can cause irreversible vision loss if not addressed within 6 hours.
• Unique in Catalonia, it has proven crucial over five years for recovering visual acuity and preventing worse complications in patients at Germans Trias Hospital.

In April 2018, Germans Trias Hospital launched a pioneering protocol for urgent care of retinal stroke, known as 'Retina Stroke Code', the ocular analogue of cerebral stroke, which has marked a turning point in the treatment of retinal stroke, a type of stroke that can cause irreversible vision loss if not treated within the first 6 hours.

Since its implementation in April 2018, the protocol has identified about 120 cases of central retinal artery occlusion (CRAO). This ocular emergency presents as a sudden, painless monocular vision loss, caused by a clot obstructing the main artery of the retina. Although a rare disease, its early detection is vital. The Retina Stroke Code, unique in Catalonia, has a multidisciplinary team of professionals in Ophthalmology, Neurology, Radiology, Neurointervention, and Emergency, enabling rapid diagnosis and treatment focused on vision recovery.

The reperfusion treatment, similar to that used in cerebral strokes, has proven effective in dissolving the thrombus causing the obstruction and restoring blood flow to the eye. This therapy, still not widely used, is the only effective one and, if applied in time, can significantly improve visual acuity. This is evidenced by about fifteen patients treated with this therapy, who experienced significant improvements in visual acuity, with a 33% success rate, compared to 5% in those untreated.

These findings are included in a study that analysed fifty cases of retinal stroke treated with the Retina Stroke Code until February last year. Published in the European Stroke Journal, one of the most impactful journals in the field of stroke, the study also provides conclusions about the causes of these strokes. One of the most notable findings is the prevalence of atrial fibrillation, a common cardiac arrhythmia in older people that causes stroke and requires anticoagulant treatment. The study found higher percentages of this atrial fibrillation, thanks to a more comprehensive study similar to that conducted for cerebral stroke.

Key to preventing blindness and other subsequent complications

Early detection of symptoms and immediate medical attention are crucial not only for visual prognosis but also for preventing future vascular events. "Working in a coordinated manner with a protocol like this is vital to improving the prognosis of these patients, not only at the visual level but also to prevent future vascular events that go beyond losing vision", points out Alejandro Bustamante, a stroke specialist at Germans Trias, a member of the Neurovascular Research Group of the Germans Trias i Pujol Research Institute (IGTP), and the first author of the article.

"If these patients are not treated, almost none improve, and they are doomed to blindness and other severe ocular complications", emphasises Susana Ruiz-Bilbao, a retinologist at the Ophthalmology Service and member of the same research group. For her, the low incidence of this disease is no reason not to take it seriously. In this sense, central retinal artery occlusion has, according to medical literature, an incidence of 1 in every 10,000 urgent ophthalmological visits, although at Germans Trias last year, this figure was 12 per 10,000 visits. "It is an existing pathology, but it must be searched for early and detected to reveal its impact", she stresses.

Both Ruiz-Bilbao and Bustamante share the need for the population to recognise, just as they are already familiar with the characteristic symptoms of a stroke, the loss of vision in one eye, suddenly and without pain or redness, as an alarm signal. "The time elapsed from the appearance of symptoms to arrival at the hospital is what has prevented us from treating more patients, and that's why it's key not to delay in seeking medical assistance", they advise. Broadly speaking, the Retina Stroke Code is activated after the Ophthalmology service diagnoses a patient who has arrived at the Emergency Department with a sudden, profound, and painless loss of vision in one eye; then, Neurology requests a neuroimaging test to assess cerebral circulation and, if appropriate, indicates a treatment to restore blood flow to the eye.

Finally, the protocol aims to incorporate artificial intelligence to accurately determine when the stroke began and its evolution time, allowing more patients to be treated and even predicting their prognosis in the not-too-distant future.

The study's significance lies not only in the improvement of visual acuity but also in its implications for general health. According to the study, the comprehensive and rapid management of CRAO is viable, even given its low incidence. Reperfusion therapies have proven to be safe and effective, resulting in a higher rate of visual recovery. Furthermore, a detailed etiological approach, aligned with that used in ischemic strokes, has enabled the identification of a high percentage of underlying causes, including 10 new diagnoses of atrial fibrillation and five carotid revascularisations. These findings underline the importance of rapid diagnosis and treatment, not only for the patient's vision but also for their long-term cardiovascular health.

Reference

Bustamante A, Balboa M, Ezcurra G, Sánchez-Fortún A, Ruiz J, Castellví J, Castillo-Acedo S, Matas È, Bouchikh R, Martínez-Sánchez M, Castaño C, Remollo S, Werner M, Salgado MC, Villodres S, Gea M, Millán M, Pérez de la Ossa N, Ruiz-Bilbao S. Implementation of a retinal stroke-code protocol results in visual recovery in patients receiving reperfusion therapies. Eur Stroke J. 2024 Jan 8:23969873231221366. DOI: 10.1177/23969873231221366.