Central retinal artery occlusion (CRAO) is a vision-threatening disorder for which there is no well-established treatment. Intra-arterial tissue plasminogen activator (tPA) has the potential to fill this gap, but it must be administered on time, according to Gareth Lema, MD, PhD, Senior Faculty, Icahn School of Medicine in Mount Sinai, New York.
Dr Lema and colleagues believe that substantial vision loss can be prevented by “treating CRAO quickly” with intra-arterial tPA when given within a 6 to 12 hour window at the end of the day. more after the onset of symptoms, as they previously reported.1
This treatment, however, is not without its challenges. Time is retina; and minutes count.
Often, patients do not present for treatment on time, or unnecessary delays in diagnosis affect treatment eligibility.
Acute, painless one-sided vision loss is not often seen as a possible stroke, Dr. Lema pointed out. Even among physicians, only about a third of ophthalmologists refer patients for emergency assessment for stroke.
If a patient presents to the emergency department on time, the only route to treatment is a full consultation with an ophthalmologist, including a dilated examination.
The objective of this new protocol is to eliminate the delay in diagnosis and to reduce the delay to treatment within 3 to 6 hours following the onset of symptoms, by eliminating the ophthalmology consultation on site.
Mount Sinai Experience
In the previously mentioned study, Dr Lema recounted, improvements in visual acuity were seen in 66% of 15 patients treated with intra-arterial tPA, 53% had 3-line improvement in vision, 4 patients who presented with counting fingers at no vision improved light perception to 20/80 vision or better. There were no major adverse events.
In the study, the mean dose of tPA was 17 mg and tPA was infused via the transfemoral arterial route. The mean processing time was 8.83 hours (range 5.5 to 12 hours).
Importantly, he stressed, these improvements exceed those of the natural course of the disease, and in some cases “dramatic improvement” has been achieved with earlier treatment.
Telemedicine, which was adopted by many ophthalmologists during the COVID-19 pandemic, may help streamline treatment for CRAO.
To speed up the diagnosis, OCT machines were placed in three stroke centers within the Mount Sinai health system.
Scans are obtained by the stroke department and transmitted to an assisting retina along with examination history and data, such as visual acuity and the student’s examination.
The diagnosis can be made in minutes and eligible patients can get treatment quickly.
Dr Lema concluded: âCRAO is visually debilitating, but building collaborative relationships with our stroke colleagues and optimizing the assessment can save vision by reducing treatment time. “
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1. Sobol EK, Sakai Y, Wheelwright D, et al. Intra-arterial tissue plasminogen activator for arterial occlusion of the central retina. Clin Ophthalmol 2021; 15-601-8.