Long-term follow-up of choroidal changes following COVID-19 infection: analysis of choroidal thickness and choroidal vascularity index

Abstract

Purpose The aim of this study was to investigate subclinical choroidal involvement in patients with systemic COVID-19 infection and evaluate its long-term course. Materials and Methods This prospective, longitudinal study included 32 eyes of 16 COVID-19 patients and 34 eyes of 17 age-matched healthy control subjects. All of the participants had a detailed ophthalmological including visual acuity assessment, slit lamp examination and indirect ophthalmoscopy. Enhanced depth optical coherence tomography imaging of the posterior pole and peripapillary region was performed at the early (days 15-40) and late (9 th month) postinfectious periods. Choroidal vascularity index (CVI) was calculated using Image-J software. Results None of the patients had any examination finding associated with the ocular involvement of COVID-19. Subfoveal choroidal thickness (SFCT) significantly decreased at the early postinfectious period compared to healthy controls (p=0.045). SFCT significantly increased at the late postinfectious period compared to early (p=0.002) and the difference between the patients and controls became statistically insignificant (p=0.362). There was a similar trend for the peripapillary choroidal thickness measurements. CVI remained unchanged (p=0.721) despite the significant decrease in SFCT and total choroidal area (TCA, p=0.042), indicating that this decrease occurred both in choroidal stroma and blood vessels. CVI remained unchanged in the late postinfectious period (p=0.575) compared to the early period, indicating that recovery occurred in the entire choroidal tissue. Conclusion This study demonstrated that choroidal thickness was reduced in all measured areas and this decrease affected all choroidal layers. This choroidopathy was reversible and recovered at the 9 th postinfectious month.

Evaluation of choroidal thickness with OCT in COVID-19 patients with high D-dimer levels

“…Firat et al reported that the choroidal thickness of patients with a relatively mild course who had COVID-19 but were not hospitalized, and no significant difference was found in the choroidal thickness compared to the control group 49 . In the study of Hepokur et al, choroidal thickness was found to decrease in COVID-19 during the early post-infectious period and to normalize during the late post-infectious period 50 . However, this study was performed in the early period of the COVID-19 pandemic and there is no anticoagulant treatment in the treatment protocol.…”

Retrobulbar ocular blood flow and choroidal vascular changes in patients recovering from COVID-19 infection

“…In our study, choroidal thickness was found to be significantly lower at all measurement points in both groups with COVID-19 when compared to the control group. Choroidal thickness and total choroidal area have been found to be significantly lower in the early postinfectious period in COVID-19 patients compared to healthy individuals in the literature [ 9 , 10 ].In contrast, the study where patients with mild COVID-19 infection were compared to a healthy control group found no significant difference in terms of choroidal thickness and CMT [11] . We think that the difference in the duration between the COVID-19 infection diagnosis and the ophthalmology examination in this study (14 to 60 days) and the differences in inflammatory cytokine density may have caused this contrasting result.…”

“…We think that the difference in the duration between the COVID-19 infection diagnosis and the ophthalmology examination in this study (14 to 60 days) and the differences in inflammatory cytokine density may have caused this contrasting result. On the other hand, studies exist on the early and late stage effects of COVID-19 infection on the ocular vascular structures [ 10 , 17 ] but whether these changes are permanent is not known. The included patients in our study were within the 3-month period folowing the COVID-19 diagnosis.…”

“…With CDU, blood flow in the ophthalmic artery (OA), central retinal artery (CRA) and vein, and short posterior ciliary artery is quantitatively evaluated [8] . Although the choroidal and retinal changes in patients with COVID-19 infection have previously been studied [9] , [10] , [11] , [12] , there is no study yet where both the choroidal and retrobulbar vascular structures have been evaluated in association with the severity of the disease. The aim in our study was to evaluate the choroid, with abundant vascular supply, and the retrobulbar ocular perfusion in patients with COVID-19 infection, and to investigate their relationship with the severity of the disease.…”

The Effect of Corticosteroid Therapy on Choroidal Thickness in Patients With Covid-19 Infection: A Prospective, Comparative, and Observational Study

“…In a previous OCT angiography study, Turker et al found an increase in choriocapillaris flow along with a decrease in vascular flow in the retinal capillary plexuses in Covid-19 patients [ 16 ]. Another study evaluated early and late choroidal thickness and choroidal vascularity index in Covid-19 patients and found that the choroidal changes detected in the early period resolved at the nine months postinfectious period [ 17 ]. Abdelmassih et al evaluated OCT images in Covid-19 patients and obtained findings in favor of choroidopathy in indocyanine green (ICG) angiography as well as choroidal thickening [ 8 ].…”