The impact of acute COVID-19 on the retinal microvasculature assessed with multimodal imaging.

PURPOSE: To quantify retinal microvascular findings in the acute phase of COVID-19 using multimodal imaging and compare them with healthy, age-matched controls. METHODS: Hospitalized patients in the acute phase of COVID-19 without known systemic comorbidities (n = 75) and healthy controls (n = 101) aged 18-65 were enrolled in this prospective cross-sectional study. The retinal microcirculation and microvasculature impairments were assessed using fundus photography, swept-source optical coherence tomography, and swept-source optical coherence tomography angiography in the COVID-19 unit and compared with healthy, age-matched controls. RESULTS: Retinal findings were predominately observed in patients with severe disease (P = 0.006). Patients with severe disease were shown to have increased both mean vein diameter (Coef. = 19.28, 95% CI: 7.34-31.23, P = 0.002) and mean artery diameter (Coef. = 11.07, 95% CI: 0.84-21.67, P = 0.044). Neither blood vessel diameters were correlated with any confounding variables (age, sex, treatment with oxygen, LDH, or ferritin). Patients with severe COVID-19 were shown to have significantly increased retinal nerve fiber layer thickness in the superior and inferior quadrants both in the inner (S: P = 0.046; I: P = 0.016) and outer (S: P = 0.026; I: P = 0.014) ring and significantly increased GCL thickness in the outer temporal quadrant (P = 0.038). There were no statistically significant differences in vessel density or the foveal avascular zone area between the groups. CONCLUSION: The severity of COVID-19 was significantly correlated with the presence of retinal microangiopathy, which could become a biomarker of angiopathy in patients with COVID-19.

The Comparison of Retinal Microvascular Findings in Acute COVID-19 and 1-Year after Hospital Discharge Assessed with Multimodal Imaging-A Prospective Longitudinal Cohort Study.

This study aimed to quantify possible long-term impairment of the retinal microcirculation and microvasculature by reassessing a cohort of patients with acute COVID-19 without other known comorbidities one year after their discharge from the hospital. Thirty patients in the acute phase of COVID-19 without known systemic comorbidities were enrolled in this prospective longitudinal cohort study. Fundus photography, SS-OCT, and SS-OCTA using swept-source OCT (SS-OCT, Topcon DRI OCT Triton; Topcon Corp., Tokyo, Japan) were performed in the COVID-19 unit and 1-year after hospital discharge. The cohort's median age was 60 years (range 28-65) and 18 (60%) were male. Mean vein diameter (MVD) significantly decreased over time, from 134.8 µm in the acute phase to 112.4 µm at a 1-year follow-up (p < 0.001). A significantly reduced retinal nerve fiber layer (RNFL) thickness was observed at follow-up in the inferior quadrant of the inner ring (mean diff. 0.80 95% CI 0.01-1.60, p = 0.047) and inferior (mean diff. 1.56 95% CI 0.50-2.61, p < 0.001), nasal (mean diff. 2.21 95% CI 1.16-3.27, p < 0.001), and superior (mean diff. 1.69 95% CI 0.63-2.74, p < 0.001) quadrants of the outer ring. There were no statistically significant differences between the groups regarding vessel density of the superior and deep capillary plexuses. The transient dilatation of the retinal vessels in the acute phase of COVID-19, as well as RNFL thickness changes, could become a biomarker of angiopathy in patients with severe COVID-19.

An Update on COVID-19 Related Ophthalmic Manifestations.

Purpose: To summarize ophthalmic manifestations of coronavirus disease (COVID-19) reported in the literature thus far.Methods: The PubMed database was systematically searched through October 24, 2020, to identify relevant articles using the following search terms: ("COVID-19" OR "SARS-CoV-2") AND ("eye" OR "ophthalmology" OR "retina" OR "retinal findings" OR "cornea" OR "conjunctiva"). Only articles published in English were included in this review.Results: The reported prevalence of ophthalmic manifestations is generally low, but correlates positively with the severity of the disease. Most commonly reported ocular manifestations are conjunctivitis, conjunctival hyperemia and chemosis. Retinal findings include microhemorrhages and flame-shaped hemorrhages, cotton wool spots, dilated veins, and tortuous vessels.Conclusion: Considering the COVID-19 cases have reached pandemic dimensions and are surging, yet again, it is of utmost importance to determine its ophthalmic manifestations and prevent their vision threatening complications. Further studies are warranted to establish whether the retinal findings appear due to the COVID-19 or are an incidental finding in patients with a preexisting diabetic or hypertensive retinopathy.