A 76-year-old woman with a history of hypertension, hyperlipidemia, atrial fibrillation, and chronic kidney disease awoke one August morning with sudden, painless vision loss in her right eye. She made an urgent appointment with a retinal specialist that day, and was ultimately referred to the Duke ED.
After a brief evaluation, it was clear that the patient had experienced a central retinal artery occlusion (CRAO or “eye stroke”), a rare type of stroke that can cause permanent vision loss in one eye if left untreated. (See Figure 1.) The vision-saving treatment available in some EDs for this condition is intravenous tissue-type plasminogen activator (tPA)—but that blood clot-busting medication is only effective for improving a patient’s chances of vision recovery if administered within 4.5 hours of symptom onset. Unfortunately, that window of time had already passed for this patient.
“It's not yet very well known that acute vision loss is an emergency, and in most cases, patients arrive at the ED too late to receive tPA for an eye stroke,” says Chantal Boisvert, MD, OD, Duke Neuro-ophthalmology division chief. No different than traditional stroke, the faster a patient who has experienced an eye stroke can call 911 and get to the nearest ED for treatment, the better the outcome.
Question: Given the time window, how did Duke eye stroke specialists reverse the woman’s sudden vision loss? What follow-up care did they recommend?
Answer: The patient underwent hyperbaric oxygen therapy to boost the oxygenation in the back of the eye and help stabilize and improve her vision. This therapy can be given within 24 after symptom onset in an effort to reverse the effects of the CRAO, but the hyperbaric team may decide to offer it 24 to 48 hours post-event, as determined on a case-by-case basis.
Duke has the only hyperbaric oxygen therapy in the Southeast that is open 24/7 on an on-call basis. Here’s how it works: The patient enters an enclosed hyperbaric oxygen chamber to boost the controlled atmospheric pressure around them, which in turn increases the amount of oxygen in their bloodstream to help repair the affected blood vessels. “It’s like diving down to the bottom of the ocean,” says Brian Mac Grory, MB, BCh, BAO, a Duke vascular neurologist who specializes in eye strokes. “This process is done gradually to allow the inner ear to cope with the change in pressure, which typically reaches two to three times the normal amount.” The patient remains in the chamber for an hour and then the pressure is gradually relieved.
After this therapy, the patient was then admitted to the hospital to undergo a full workup, including an MRI and echocardiogram, to assess any arterial damage and monitor her visual recovery. When she was discharged 48 hours later, her vision in the right eye had already significantly improved due to the hyperbaric oxygen treatment.
“She really feels that the treatments received at Duke saved her vision,” Boisvert says.
Best practices for eye stroke follow-up care
The patient began her follow-up care three weeks later at the Duke Eye Stroke Clinic, a multidisciplinary clinic specializing in the care of patients who have experienced retinal artery occlusion and other types of strokes that affect vision (including strokes affecting the vision pathways in the brain). The goal of this clinic is to provide follow-up care every few months to ensure that each patient’s risk factors are under control to prevent another stroke and to connect patients with Low Vision/Vision Rehabilitation specialists who help them to adapt to managing tasks in their daily life.
“Oftentimes after an eye stroke, patients may have a hard time pouring liquid into cups or reaching out for objects. Driving is more difficult as well for those missing a large part of their peripheral vision,” Boisvert says. “Our clinic is here to ensure that patients are all optimized in terms of their visual needs, and to ensure that the patient’s other eye stays healthy.”
Highlights of the Duke Eye Stroke Clinic include:
- access to expertise in neurology, neuro-ophthalmology, and vision occupational therapists at each visit
- advanced vision testing capabilities for patients in one location
- clear communication among the specialists on a patient’s care team
Quick reference about eye stroke symptoms and risk factors
While eye strokes account for fewer than 1% of all strokes (about 6,000 to 8,000 people in the U.S. annually), they can be devastating and debilitating to those who experience it, Mac Grory notes. Patients who experience eye stroke tend to be older in age and have one or more of the following risk factors: hypertension, hyperlipidemia, diabetes, and being a smoker.
Patients and providers should be aware of the symptoms of eye stroke, which include:
- Vision loss in one eye
- Darkening of vision at the top or bottom of the eye
- Acute onset
The Duke Eye Stroke Clinic specializes in the care of patients who have experienced retinal artery occlusion and other types of strokes that affect vision.