Objective To quantify the density of the macular microvasculature and the area of the foveal avascular zone (FAZ) in patients recovered from Coronavirus Disease 2019 (COVID-19) using optical coherence tomography angiography (OCTA) analysis. Methods In a comparative cross-sectional, observational study, patients recovered from COVID-19 were included in this study. All included subjects exhibited a reverse transcription-polymerase chain reaction (RT-PCR) - confirmed diagnosis of COVID-19. Spectral domain macular OCTA was performed at least 2 weeks after recovery from systemic COVID-19. Vessel density (VD) of the superficial (SCP) and deep retinal capillary plexus (DCP) and the area of the FAZ were measured in COVID-19 recovered patients versus age-matched normal controls. Results Thirty-one recovered COVID-19 patients and 23 healthy normal controls were studied. Mean quality scan index was 7.64±0.66 in the COVID cases and 8.34±0.71 in the normal controls (p=0.001). Mean SCP VD and DCP VD of the COVID cohort was significantly lower than the SCP VD and DCP VD of the control group in the foveal and parafoveal regions. FAZ area was greater in the COVID cohort, but this difference was not statistically significant. In addition, in the COVID cohort, VD of the SCP and DCP were lower in patients with a history of COVID-19 hospitalization versus those without such a history but this did not reach statistical significance. Conclusion Patients recovered from COVID-19 displayed alterations in the retinal microvasculature including a significantly lower VD in the SCP and DCP. Patients with coronavirus infection may be at risk of retinal vascular complications.

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Background/aims To quantify the longitudinal changes of the macular microvasculature and the foveal avascular zone (FAZ) parameters in patients recovered from coronavirus disease-2019 (COVID-19) using optical coherence tomography angiography (OCTA) analysis. Methods This observational, longitudinal study was performed on patients recovered from COVID-19. The OCTA images were recorded at baseline and after 1 and 3 months at the follow-up examination. Vessel density (VD) of the retinal superficial (SCP) and deep capillary plexus (DCP), as well as the area of the FAZ of patients who had recovered from COVID-19, were measured. Results In total, 36 eyes of 18 patients (62.2% female) with a mean age of 34.5 ± 7.5 years old were included. Regarding SCP, while the VDs of the whole image, fovea, and parafovea were comparable at different time points, the mean VDs in inferior hemifield, as well as superior and inferior regions of perifovea, underwent significant reductions at month 3, compared to the baseline. In DCP, the mean of VD in the whole image was 54.3 ± 2.7 at the first visit which significantly decreased to 52.1 ± 3.8( P = 0.003) and 51.4 ± 2.7( P = 0.001) after 1 and 3 months, respectively. The VDs in all regions of parafovea and perifovea revealed a significant reduction after 1 and 3 months, compared to the first visit. The mean FAZ area was 0.27 ± 0.08 mm 2 , 0.26 ± 0.08 mm 2 , and 0.27 ± 0.08 mm 2 at the baseline, month 1, and month 3, respectively ( P > 0.05). Conclusion Based on the results, the patients who had recovered from COVID-19 had a progressive decrease of VD at the follow-up visit 3 months after COVID-19 infection.

Objectives This study aimed to evaluate the retinal and choroidal changes in the macular region of patients with Coronavirus Disease 2019 (COVID-19) using structural spectral-domain optical coherence tomography (SD-OCT) analysis. Methods This cross-sectional observational case-control study included patients recovered from COVID-19. The COVID-19 in all participants was confirmed using the reverse transcription-polymerase chain reaction (RT-PCR) technique. The participants had mild to moderate degree of disease without a history of hospitalization, steroid usage, or blood saturation below 92%. Macular SD-OCT was performed at least two weeks and up to one month after recovery from systemic COVID-19. Quantitative and qualitative changes detected by macular SD-OCT imaging were evaluated in COVID-19 recovered patients and compared with the results of age-matched normal controls. Results Participants in this study included 30 cases (60 eyes) and 60 healthy controls (120 eyes). In total, 17 (28.3%) eyes in patient group showed at least one abnormal finding indicated by macular SD-OCT imaging included hyperreflective lesions in different retinal layers. In addition, dilated choroidal vessels and retinal pigment epitheliopathy were evident in 41 (68.3.6%) and 4 (6.6%) eyes in patient group, respectively, and their OCT findings resembled those with pachychoroid spectrum. No statistically significant differences were observed in retinal layers or retinal volume between the two groups. The mean ± SD subfoveal choroidal thickness (SFCT) was determined at 380.3 ± 12.40 μm, which was significantly thicker than that in control group (310.7 ± 57.5 μm) (P < 0.001). Conclusion Regarding retinal thickness, no significant change was observed in different retina layers of patients with COVID-19; however, there were striking qualitative changes, such as hyperreflective lesions in different retinal layers. The evaluation of choroidal structure and thickness demonstrated remarkable abnormal pachyvessels and significant thickening of the SFCT but the clinical significance of these findings is unknown.

Objective. To evaluate the midterm longitudinal changes in chorioretinal structures in patients with coronavirus disease 2019 (COVID-19). Methods. Thirty-four eyes of 17 COVID-19 patients were enrolled. The patients underwent retinal and choroidal imaging upon the recovery (baseline) after 1 and 3 months. Retinal measurements in fovea, parafovea, and perifovea were recorded. To calculate choroidal vascularity index (CVI), luminal and total choroidal areas were measured using Sonada's method. Choroidal thickness was measured at the subfovea 500 microns temporal and nasal to the fovea. Results. Mean CVI was 0.64 ± 0.04 at baseline that significantly increased to 0.67 ± 0.05 (P = 0.012) after 1 month and again significantly decreased to 0.63 ± 0.05 after 3 months (P < 0.001). While the stromal component showed a significant decrease between the baseline and first-month values (1.16 ± 0.29 to 1.01 ± 0.27, P = 0.03), the luminal area mostly changed between months 1 and 3 (2.03 ± 0.28 to 1.91 ± 0.23, P = 0.045). The average of subfoveal choroidal thickness and retinal thickness remained unchanged. Conclusion. CVI is increased in patients with COVID-19 1 month after recovery from COVID-19 and returns to baseline values after 3 months. Regarding the reversible nature of changes, there might be a prominent role in inflammation.

Objective: To evaluate choroidal thickness in the macular region of patients with coronavirus disease 2019 (COVID-19).Methods: Patients recovered from COVID-19 were included in this cross-sectional study. Macular imaging with an SD-OCT device was performed at least 2 weeks after recovery from systemic COVID-19 and choroidal thickness was measured as the main outcome measure.Results: Thirty-four subjects were included in this study. One patient was monocular and high-quality SD-OCT images were available for the remaining 67 eyes. Dilated choroidal vessels were observed in 55 eyes (82%) and retinal pigment epitheliopathy was noticeable in 4 eyes (6%); these findings resemble those of the pachychoroid spectrum. The mean subfoveal choroidal thickness (SFCT) in our patients was 380.3±12.40 µm, which was significantly thicker than the previously reported SFCT in the normal population (310.7 ± 57.5 µm) (p<0.001).Conclusion: Patients with COVID-19 demonstrate remarkable changes in the choroid of the macular region.

Purpose: To quantify the microvasculature density of the optic nerve head (ONH) using optical coherence tomography angiography (OCTA) analysis in patients recovered from Coronavirus Disease 2019 (COVID-19). Methods: In a comparative cross-sectional, observational study, patients recovered from COVID- 19 whose initial diagnosis was confirmed by an rRT-PCR of a nasopharyngeal sample were included in this study. OCTA of ONH was performed in included patients and normal controls. Vascular density (VD) of the all vessels (AV) and small vessels (SV) inside the disc and radial peripapillary capillary (RPC) network density was measured in COVID-19 recovered patients and compared with similar parameters in an age-matched group of normal controls. Results: Twenty-five COVID-19 patients and twenty-two age-matched normal controls were enrolled in the study and one eye per participant was evaluated. The mean whole image SV VD in the COVID-19 group (49.31 ± 1.93) was not statistically significantly different from that in the control group (49.94 ±. 2.22; P = 0.308). A decrease in RPC VD was found in all AV and SV VD measured, which became statistically significant in whole peripapillary SV VD, peripapillary inferior nasal SV VD, peripapillary inferior temporal SV VD, peripapillary superior nasal SV VD, and grid-based AV VD inferior sector (P < 0.05). Inside disc SV VD in the COVID-19 group (49.43 ± 4.96) was higher than in the control group (45.46 ± 6.22) which was statistically significant (P = 0.021). Conclusion: Unremarkable decrease was found in ONH microvasculature in patients who had recovered from COVID-19. These patients may be at risk of ONH vascular complications. Increase in inner disc SV VD may be an indicator of ONH hyperemia and edema.

Purpose: To quantify the retinal thickness and volume using spectral-domain optical coherence tomography (SD-OCT) analysis in the macular region of patients with Coronavirus Disease 2019 (COVID-19).Methods: In a comparative cross-sectional, observational study, patients recovered from COVID-19 were included. All included subjects had a reverse transcription-polymerase chain reaction (RT-PCR) - confirmed diagnosis of COVID-19. Macular SD-OCT was performed at least two weeks after recovery from systemic COVID-19. Inner, outer and full retinal thicknesses and volumes were measured in COVID-19 recovered patients versus age-matched normal controls.Results: Twenty-five patients (11 male) with a mean age of 36.4 ± 11 years and 60 healthy controls (31 males) with a mean age of 39.3 ± 7.7 years were enrolled in the study. There was no statistically significant difference in the retinal thickness or volume measures between the two groups. However, the thickness in the case group was minimally more than the controls. Conclusion: Retinal thickness in COVID-19 patients may be higher than healthy subjects. Comprehensive ocular examination with special focus on posterior segment manifestations should be considered in these patients.