Retinal microvascular changes may not predict short-term ischemic events

The FOTO-TIA study that focused on retinal microvascular changes reported that the changes seen in patients with suspected transient ischemic attacks (TIAs) in the emergency department do not improve the ability to predict future ischemic events (ie, stroke and cardiovascular events) during the ensuing 90 days, according to the first author of the study, Valérie Biousse, MD, professor of neuro-ophthalmolopgy at the Emory Eye Center in Atlanta, Georgia.

This is despite the fact that the microvascular findings in the patients are independent risk factors that differentiate TIAs and strokes from mimics.

The FOTO-TIA study

About a quarter to a half million people in the US have a TIA annually. Of these, approximately 10% are estimated to have a stroke during the subsequent 90 days. The FOTO-TIA study was undertaken to determine whether the retinal microvascular findings were helpful for predicting strokes and cardiovascular events in patients who presented with a suspected TIA. The investigators conducted a cohort study to address this question.

Adults with a National Institutes of Health Stroke Scale score of 3 or less were admitted for observation to 3 emergency departments for an accelerated diagnostic protocol for a suspected TIA or stroke. Nonmydriatic fundus photographs were obtained prospectively for all patients and reviewed for retinal microvascular findings that included retinal hemorrhages, cotton wool spots, retinal emboli/occlusions, hard exudates, or microaneurysms.

Study findings

The investigators noted that of the 395 study patients (median age, 57 years; 55% women; 64% Black), 34 (9%) had retinal microvascular findings. A total of 154 patients completed the 90-day follow-up evaluation.

Within the 90-day time frame, 3 (0.8%) of the 395 patients had a stroke, 3 (0.8%) had a recurrent TIA, and none had a cardiovascular event. “All the patients who had a stroke or recurrent TIA had an ABCD2 score over 3 compared with 70% of the other patients (P = .25),” Biousse said. The ABCD2 score is a tool to improve the ability to predict the risk of short-term stroke after a TIA. Importantly, none of the patients who had a stroke or recurrent TIA had microvascular findings compared with 9% of the patients who had microvascular findings (P = .59).

The investigators concluded that this study did not show evidence that retinal microvascular findings in patients with suspected TIA in the emergency department improve the short-term predictability of future ischemic events. They pointed out that the study was underpowered because of the much lower incidence of short-term stroke than what they had anticipated. They credit this largely to the improved accelerated diagnostic protocol among the patients.

Valérie Biousse, MD

E: vbiouss@emory.edu

This article is adapted from Biousse’s presentation at the American Academy of Ophthalmology 2021 annual meeting in New Orleans, Louisiana. Biousse has no financial interest in this subject matter.