IMPACT OF COVID-19 AND RETINAL BLOOD VESSELS
Keywords:
COVID-19, optical coherence tomography, retina, cotton wool spot, microvascularAbstract
The people with COVID-19 can develop eye problems, which can be ranged from mild to vision-threatening. There is a chance that some people with COVID-19 experience inflammation throughout their body, which can be a reason for blood clots forming. These clots can travel through the body and reach the arteries, veins and blood vessels of the eye.The purpose of this study is to estimate the presence of retinal and microvascular modifications in COVID-19 patients with bilateral pneumonia due to SARS-COV-2 that requires hospital admission and correlate this with a group of sex and age matched controls. These patients went through retinal imaging 14 days after hospital discharge with optical coherence tomography angiography (OCTA) measurements and structural optical coherence tomography (OCT). Foveal avascular zone (FAZ) area and Vessel density (VD) were checked in the superficial, choriocapillaris (CC) and deep capillary plexus (SCP, DCP). In the analysis, after exclusion criteria, only one eye per patient was selected, and 50 eyes (25 controls and 25 paniet) were included. Patients with COVID-19 presented significantly thinner ganglion cell layer and massive retinal nerve fiber layer compared to controls, and this RNFL thickening was greater in COVID-19 cases with cotton wool spots (CWS), when compared with patients without cotton wool spot. In both DCP and SCP, COVID-19 patients presented lower VD in the foveal region and a greater FAZ area than controls. These findings suggest that inflammatory and thrombotic phenomena could happenn in the retina of COVID-19 patients.
COVID-19 is caused by SARS-KOV-2, a new beta-coronavirus that causes a life-threatening infection that causes more than 1 million deaths worldwide. To enter human cells, SARS-KOV-2 uses spiked proteins that bind directly to a strong affinity for human angiotensin converting enzyme 2 (ACE2). COVID-19 can cause serious acute respiratory diseases, distress syndrome, associated with a prothrombotic condition, and multiorgan failure with a high mortality rate in some cases.
The virus transmits when people breathe in air contaminated by droplets and small airborne particles containing the virus. The risk of breathing these in is highest when people in close proximity, but they can be inhaled over longer distances, particularly indoors. Transmission can also occur if splashed or sprayed with contaminated fluids in the eyes, nose or mouth, and, rarely, via contaminated surfaces. People remain contagious for up to 20 days, and can spread the virus even if they do not develop symptoms.
References
Channappanavar, R., & Perlman, S. (2017). Pathogenic human coronavirus infections: causes and consequences of cytokine storm and immunopathology. Semin Immunopathol, 39(5), 529-539.
Chen, N., Zhou, M., Dong, X., Qu, J., Gong, F., Han, Y., Qiu, Y., Wang, J., Liu, Y., & Wei, Y. (2020).
Coronavirus disease (COVID-19) Situation Report 128. https://www.who.int/emergencies/diseases/novelcoronavirus-2019/situation-reports.
Epidemiological and clinical characteristics of 99 cases of 2019 novel coronavirus pneumonia in Wuhan, China: a descriptive study. Lancet, 395(10223), 507–13.
Fruchter, O., Yigla, M., & Kramer, M.R. (2015). D-dimer as a prognostic biomarker for mortality in chronic obstructive pulmonary disease exacerbation. Am J Med Sci., 349(1), 29–35. Gralinski, L.E., & Baric, R.S. (2015). Molecular pathology of emerging coronavirus infections. J Pathol., 235(2),185-95.
Huang, C., Wang, Y., Li, X., Ren, L., Zhao, J., Hu, Y., Zhang, L., Fan, G., Xu, J., & Gu, X. (2020). Clinical features of patients infected with 2019 novel coronavirus in Wuhan, China, Lancet (London, England), 395(10223), 497–506.
Jorge González-Zamora, V.-M.-P.-V.-V.-L. (2021). Retinal Microvascular Impairment in COVID-19 Bilateral Pneumonia Assessed by Optical Coherence Tomography Angiography.
Linkins, L.A., & Takach Lapner, S. (2017). Review of D-dimer testing: good, bad, and ugly. Int J Lab Hematol., 39(S1), 98–103.
Lippi, G., Bonfanti, L., Saccenti, C., & Cervellin, G. (2014). Causes of elevated D-dimer in patients admitted to a large urban emergency department. Eur J Intern Med., 25(1), 45–8.
Mrittika Sen, S. G. (2021, February 17). COVID-19 and Eye: A Review of Ophthalmic Manifestations of COVID-19.
Tang, N., Li, D., Wang, X., & Sun, Z. (2020). Abnormal coagulation parameters are associated with poor prognosis in patients with novel coronavirus pneumonia. J Thromb Haemost., 2020(18), 844–847.
Umi K., & Noh, S. Y. (2015). Central Retinal Artery Occlusion Following Central Retinal Vein.
Yang, Y., & Tang, H. (2016). Aberrant coagulation causes a hyper-inflammatory response in severe influenza pneumonia. Cell Mol Immunol.,13(4), 432–42.
Xu, Z., Shi, L., Wang, Y., Zhang, J., Huang, L., Zhang, C., Liu, S., Zhao, P., Liu, H., & Zhu, L.(2020). Pathological findings of COVID-19 associated with acute respiratory distress syndrome. Lancet Respir Med., 8(4), 420–2.