May is Stroke Awareness Month
May is Stroke Awareness Month in the US! Did you know that not only can you have a stroke that affects your brain tissue, but also the Retina?
These “Strokes” are essentially occlusions, or blockages, to one of the arteries feeding the retina, called Central Retinal Artery Occlusion and Branch Retina Artery Occlusion (CRAO and BRAO). This event restricts or completely cuts off the blood flow to the Central or a Branch Artery in the back of the eye. Unfortunately, this Occlusion event often leads to unrecoverable vision loss as the affected area of the Retina, which is nerve tissue, goes an extended period without proper blood flow. In some rare cases, the artery may “perfuse” and some blood flow may return to the affected area of the Retina.
The usual suspect for the embolism in these Retinal Artery Occlusions is a piece of plaque, usually comprised of cholesterol, calcium, or other platelet fibrin. These emboli usually originate from a partially blocked artery elsewhere in the body, such as the carotid artery. This process of an embolism happening within a Retinal Artery is the similar to the process of a blockage occurring in an artery in the brain, leading to a stroke. Because of this fact, CRAO and BRAO events are taken very seriously as they could be indicators for a patient being at higher risk of a stroke.
According to a recent article publish at AAO.org, a study found of 89 identified patients with a CRAO, in the 15 days before and after CRAO, 2 patients had ischemic strokes and 1 patient had a nonischemic stroke (3.4% of the study population). In addition, 2.2% of patients had a Transient Ischemic Attack (TIA) and 10.1% experienced Transient Monocular Vision Loss (TMVL). The American Heart Association published a scientific statement which stressed that CRAO is a medical emergency requiring an emergent workup. This is because CRAO is thought to be the equivalent of a stroke or TIA. All of the patients who developed a stroke or TIA in the time period before and after CRAO had an embolic etiology, showing the importance of a full workup surrounding the event. (https://www.aao.org/editors-choice/increase-in-stroke-complications-seen-several-days)
To learn more about RAO's and other conditions we treat please visit our learning center.
Content provided by TN Retina Member
Michael Nore, COA
Assistant Clinical Manager