Retinal Microvascular Changes in COVID-19 Bilateral Pneumonia Based on Optical Coherence Tomography Angiography

Abstract

The purpose of this study was to evaluate retinal and choroidal microvascular alterations with optical coherence tomography angiography (OCTA) in COVID-19 patients hospitalized because of bilateral pneumonia caused by SARS-CoV-2. The vessel density (VD) and foveal avascular zone (FAZ) of 63 patients with SARS-CoV-2 pneumonia who had positive polymerase chain reaction (PCR) tests and who recovered after receiving treatment and 45 healthy age- and gender-matched controls were evaluated and compared using OCTA in the superficial capillary plexus (SCP) and deep capillary plexus (DCP). The VD was also estimated in both groups in the choriocapillaris (CC). In COVID-19 patients, there was a statistically significant difference between the patients and a control group in both superficial (FAZs) and deep (FAZd) avascular zone (p = 0.000). The VD was significantly lower in the foveal area in choriocapillaris (p = 0.046). There were no statistically significant changes in the VD in the superior, inferior, nasal, and temporal quadrants in superficial and deep plexus, or in the choriocapillaris. The VD was not significantly lower in the foveal area in superficial or deep plexus. COVID-19 may affect the retinal vasculature, causing ischemia, enlargement of the FAZ, and lowering of the VD in the choriocapillaris area. Routine ophthalmic examination after SARS-CoV-2 infection should be considered in the course of post-infectious rehabilitation.

Long-Term Effect of SARS-CoV-2 Infection on the Retinal and Choroidal Microvasculature

“…As described in our previous paper, we excluded patients with eye and systemic diseases that could have affected the measurement outcomes, as previously described [ 4 ].…”

“…The foveal avascular zone (FAZ) in the SCP and in the DCP was manually delineated by two independent graders, encompassing the central fovea, where no clear and demarcated vessels were seen on the OCTA. Scan quality over 65% was a threshold for eligibility for the study, as previously described [ 4 ].…”

“…In our previous study, we used optical coherence tomography (OCT) to evaluate the retinal and choroidal microvasculature and neuroretinal structures in hospitalized patients with bilateral pneumonia due to SARS-CoV-2. We found a decreased vascular density (VD), enlarged foveal avascular zone (FAZ), thickened retinal nerve fibre layer (RNFL), and thinner ganglion cell layer (GCL) in foveal and parafoveal areas in COVID-19 patients compared to a cohort of age and sex-matched healthy controls [ 4 ]. Our results were consistent with those of other authors [ 5 , 6 ].…”

Retinal tissue and microvasculature loss in COVID-19 infection

“…This is a new finding since there were no available studies to compare retinal volume in COVID-19-recovered patients. Some groups 18 , 20 , 23 also found that the FAZ is larger in patients who recovered from COVID-19 infection compared to normal controls; however, other groups 14 , 15 , 21 , 22 , 24 found no difference. Our group found no significant difference between the three groups regarding the FAZ area, circularity, and roundness related to COVID-19 infection or severity.…”

Retinal microvascular changes in patients recovered from COVID-19 compared to healthy controls: A meta-analysis

“…The electronic database search identified 754 articles. After screening of all titles and abstracts of potentially relevant articles, a total of 12 studies met the inclusion criteria [16] , [17] , [18] , [19] , [20] , [21] , [22] , [23] , [24] , [25] , [26] , [27] , [28] ( Figure 1 ). The study characteristics and Newcastle Ottawa scores of the included studies are presented in Table 1 .…”