Ophthalmologic Analysis of COVID-19 Long-Haulers using Optical Coherence Tomography Angiography

Project: Research project

Project Details


With 3.2 million deaths and over 150 million cases worldwide, the rapidly evolving SARS-CoV-2 pandemic remains the most significant global health crisis today. Although the morbidity of COVID-19 is primarily due to its respiratory involvement, it also has the propensity to cause multiorgan failure via vascular endothelial dysfunction. There is a growing body of research exploring the vascular ocular manifestations of COVID-19. Data from human retinal biopsies of deceased COVID-19 patients demonstrated a SARS-CoV-2 viral RNA detection rate of 21%, suggesting a potential tropism of SARS-CoV-2 for the eye. Preliminary studies utilizing optical coherence tomography angiography (OCT-A) imaging yielded conflicting data on retinal vascular density changes in recovered COVID-19 patients. Consequently, the impact of COVID-19 on retinal vasculature, as demonstrated by OCT-A, remains uncertain. Although SARS-CoV-2 usually causes a brief, sometimes severe infection, there is an emerging population of COVID-19 patients who exhibit symptoms for 6 or more weeks status post symptom onset. These patients are classified as COVID-19 long-haulers and in one study, made up 32% of COVID positive patients in an outpatient setting. Classically, long-hauler COVID-19 patients exhibit persistent shortness of breath, loss of smell & taste, but recent data from Graham et al demonstrate that numerous long-haulers also exhibit persistent neurologic symptoms such as brain fog in 81% and blurry vision in 30%. No studies have yet been conducted on long-hauler COVID-19 patients exhibiting neurologic symptoms to characterize their ophthalmic findings. In our study, we will perform a comprehensive ophthalmic examination and obtain multi-modal imaging (OCT/OCT-A, fluorescein angiography, fundus photography) on non-hospitalized COVID-19 long-haulers with neurologic symptoms (brain fog and blurry vision). This is a prospective, observational study pending IRB approval where subjects will be recruited from Northwestern Medicine’s Neuro COVID-19 clinic. We will compare the data from long-haulers with neuro-ophthalmic symptoms (brain fog and blurry vision) to long-haulers without blurry vision and healthy COVID-negative control patients. The primary endpoints for this study will OCT-A parameters of macular and peripheral vessel density, foveal avascular zone size, and retinal perfusion status. Numerous other secondary quantitative parameters will be analyzed such as retinal nerve fiber thickness, ganglion cell layer thickness, central macular thickness, and fluorescein angiography where indicated. We hypothesize that long-hauler COVID-19 patients experiencing neuro-ophthalmic symptoms may demonstrate quantifiable changes in retinal vessel density when compared to long-haulers without ocular symptoms and healthy controls. Our study is the first to examine ophthalmic sequelae of SARS-CoV-2 in long-haulers exhibiting ocular complaints which may provide insight into the mechanism of the neurologic complaints in this population of patients, This may help identify patients at risk, prognosticate and inform physicians regarding potential therapies. In doing so, we hope to attenuate the morbidity of this debilitating disease.
Effective start/end date7/1/216/30/23


  • Illinois Society for the Prevention of Blindness (Letter 6/17/2021)


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