Related Experiment Video
Updated: Oct 18, 2025
Fundus Photography as a Convenient Tool to Study Microvascular Responses to Cardiovascular Disease Risk Factors in Epidemiological Studies
Published on: October 22, 2014
The Impact of Coronavirus Disease 2019 (COVID-19) on Retinal Microcirculation in Human Subjects
Emre Aydemir1, Gozde Aksoy Aydemir1, Halil Ibrahim Atesoglu2
1Ophthalmology Department, Adıyaman University Training and Research Hospital, Adıyaman, Turkey.
Insights
Optical coherence tomography angiography revealed higher superficial parafoveal vessel density in recovered COVID-19 patients compared to controls. This suggests potential long-term impacts of coronavirus disease 2019 on retinal microvasculature.
Area of Science:
- Ophthalmology
- Cardiovascular Research
- Infectious Diseases
Background:
- Coronavirus disease 2019 (COVID-19) can affect various organ systems.
- The impact of COVID-19 on retinal microcirculation remains an area of investigation.
Purpose of the Study:
- To evaluate retinal microcirculation in COVID-19 survivors using optical coherence tomography angiography (OCT-A).
- To compare OCT-A findings in recovered COVID-19 patients with healthy controls.
Main Methods:
- Enrolled 39 recovered COVID-19 patients and 40 healthy controls.
- Utilized OCT-A (AngioVue software, RTVue XR Avanti system) for image acquisition.
- Measured superficial capillary plexus (SCP) and deep capillary plexus vessel density (VD), foveal avascular zone (FAZ) area, and other retinal microvascular parameters.
Main Results:
- Superficial parafoveal VD was significantly higher in the COVID-19 group compared to controls (p < 0.05).
- No statistically significant differences were observed in nonflow area or FAZ area between groups (p > 0.05).
- Other VD parameters showed non-significant differences between the groups.
Conclusions:
- Recovered COVID-19 patients exhibit significantly higher parafoveal SCP vessel density.
- These findings highlight the lasting effects of COVID-19 on retinal microvasculature.
- Altered retinal microvasculature may represent a risk factor for future ocular diseases.
Background:
The aim of the study was to assess retinal microcirculation in patients with coronavirus disease 2019 (COVID-19) through the use of optical coherence tomography angiography (OCT-A) and compare the results with those obtained in healthy controls.
Methods:
The study enrolled 39 patients who had fully recovered from COVID-19 and 40 healthy controls. OCT-A image acquisitions were obtained using AngioVue software (version 2017.1.0.151) and the RTVue XR Avanti imaging system (Optovue Inc., Fremont, CA, USA). Nonflow area in the superficial capillary plexus (SCP), foveal avascular zone (FAZ) area in the whole retinal vasculature, FAZ perimeter, acircularity index of FAZ, and foveal density were automatically obtained with the FAZ assessment tool. Vessel density (VD) at the SCP and deep capillary plexus were also measured.
Results:
Compared to the control group, the nonflow area and the FAZ area in the whole retina was greater in the COVID-19 group; however no statistically significant difference was observed (p > 0.05 respectively). As for vessel densities, all superficial parafoveal VD parameters were considerably higher in the COVID-19 group compared to the control group (p < 0.05 respectively). Despite the fact that the vessel densities in the remaining zones were lower in the COVID-19 group, those differences were not statistically significant (p > 0.05 respectively).
Conclusion:
VD at the parafoveal area of the SCP was significantly higher among patients in the late post-recovery period of COVID-19 disease compared to healthy controls. These findings show the impact of COVID-19 on the retinal microvasculature and its possible role as a risk factor for the development of ocular diseases.
