Evaluation of vascular and perfusional changes in the retina and choroid of children with multisystem inflammatory syndrome.

BACKGROUND: Multisystem inflammatory syndrome in children (MIS-C) is hyperinflammation following coronavirus disease 2019 (COVID-19), which affects many organs. The retina and choroid are affected by COVID-19 through microangiopathy and thrombosis but the literature on MISC-C is limited. METHODS: Thirty children (60 eyes) with MIS-C (the study group, or SG) and 32 age-and gender-matched healthy children (64 eyes) (the control group, or CG) were included in the prospective case-control study. Complete ophthalmological examinations, measurements of the vessel densities of the retinal layers, and flow area of the outer retina and choriocapillaris in both groups were conducted with optical coherence tomography angiography (OCT-A). RESULTS: The mean age of the SG was 11.9 ± 3.9 and that of the CG was 12.5 ± 4.6 years (p = 0.197). In this study we found that the vessel density of the deep layer of the inner retina was decreased significantly and was reduced in the outer retina of flow area in the SG in comparison with the CG (p < 0.05, for all). However, there was no significant difference between the groups regarding other measurements. CONCLUSIONS: In MIS-C patients, vessel densities in the deep layer of the inner retina and in the flow area of the outer retina decreased significantly. This OCTA-A finding suggests that MIS-C is related to endothelial thrombotic condition problems in small branches of the retinal artery. The results of this study support the idea that there is a need for screening of MIS-C patients for the presence of these microangiopathic and perfusional complications.

Investigation of changes in retinal vascular parameters and choroidal vascular index values during the early recovery period of COVID-19: The COVID-OCTA study.

BACKGROUND: COVID-19 effects microvasculature in many tissues. This study investigated whether the choroidal structure is also affected. METHODS: This cross-sectional study included 80 patients with COVID-19 and the same number of age- and gender-matched healthy individuals. All participants' right eye measurements were examined. Optical coherence tomography angiography (OCTA) was used for imaging. Otherwise, two independent researchers used the Choroidal vascular index (CVI) for choroidal parameters calculation. RESULTS: Superior and deep flow values were lower in the COVID-19 group than in the control group, and vascular density (VD) values were lower in all regions in this group. Except for the superior mean VD, there was no statistically significant difference (p = 0.003). However, the COVID-19 group had significantly lower subfoveal choroidal thickness (SFChT) measurements than the control group (p = 0.001). In addition, no significant difference was observed between the groups in evaluating mean CVI values (p>0.05). CONCLUSION: Noninvasive diagnostic tools such as OCTA and EDI-OCT can be used to monitor early changes in diseases affecting microvessels, such as from COVID-19.

Analysis of swept-source optical coherence tomography angiography measurement alterations in adult patients recovered from COVID-19.

CLINICAL RELEVANCE: Vessel density (VD) measurements obtained using swept-source optical coherence tomography angiography (SS-OCTA) of the retinal layers and choriocapillaris have the capacity to demonstrated retinal changes in COVID-19 patients. BACKGROUND: To investigate VD changes in the retinal layers and choroid using SS-OCTA in patients recovered from COVID-19. METHODS: This cross-sectionally designed study was conducted in a single eye centre. The diagnosis of COVID-19 disease was confirmed by a polymerase chain reaction test. Patients who had fully recovered from COVID-19 served as the COVID-19 group, and the control group comprised age- and gender-matched healthy subjects. VD measurements in the superficial and outer retina layers and the choriocapillaris were performed using SS-OCTA. RESULTS: VD measurements in the central fovea and all quadrants of superficial and deep retinal layers, and the choriocapillaris, showed a significant decrease in the COVID-19 group (P < 0.05 for all) compared to the control group. Significant reductions in VD measurements were more prominent in the choriocapillaris when compared to the retinal layers. Mean ferritin and C-reactive protein (CRP) concentrations showed negative correlations with VD measurements in certain quadrants of the deep retinal layer and choriocapillaris. CONCLUSION: VD reductions occur the superficial and deep retinal layers and choriocapillaris in patients with pre-existing COVID-19. These results suggested the use of SS-OCTA as a microvascular biomarker and an auxiliary technique for the diagnosis and follow-up of COVID-19.

Ocular Pathology and Occasionally Detectable Intraocular Severe Acute Respiratory Syndrome Coronavirus-2 RNA in Five Fatal Coronavirus Disease-19 Cases.

INTRODUCTION: In December 2019, the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) pandemic broke out. The virus rapidly spread globally, resulting in a major world public-health crisis. The major disease manifestation occurs in the respiratory tract. However, further studies documented other systemic involvement. This study investigates histopathologic eye changes in postmortem material of coronavirus disease 2019 (COVID-19) patients. METHODS: Sections of formalin-fixed, paraffin-embedded eyes from 5 patients (10 eyes) who died of COVID-19 at the University Hospital in Basel were included. Gross examination and histological evaluation were performed by 3 independent ophthalmopathologists. Immunohistochemical staining was performed using antibodies against fibrin, cleaved caspase 3, and ACE-2. Five enucleated eyes of patients not infected with SARS-CoV-2 served as control group. All cases have been studied for presence of SARS-CoV-2 RNA by means of reverse transcription PCR and RNA in situ hybridization (ISH). The choroidal vessels of one case were analyzed with electron microscope. RESULTS: Ophthalmopathologically, 8 eyes from 4 patients displayed swollen endothelial cells in congested choroidal vessels. No further evidence of specific eye involvement of SARS-CoV-2 was found in any of the patients. In the 8 eyes with evidence of changes due to SARS-CoV-2, immunohistochemical staining demonstrated fibrin microthrombi, apoptotic changes of endothelial and inflammatory cells. In control eyes, ACE-2 was detectable in the conjunctiva, cornea, retina, and choroidea and displayed significantly lower amounts of stained cells as in COVID-19 eyes. SARS-CoV-2 RNA was detectable in both bulbi of 2/5 patients, yet ISH failed to visualize viruses. Electron microscopy showed no significant results due to the artifacts. DISCUSSION/CONCLUSION: As already described in other organs of COVID-19 patients, the ophthalmological examination revealed-microthrombi, that is, hypercoagulation and vasculopathy most probably due to endothelial damage. A possible viral spread to the endothelial cells via ACE-2 provides one pathophysiological explanation. The expression of ACE-2 receptors in the conjunctiva hints toward its susceptibility to infection. To what extend eyes, function is disrupted by SARS-CoV-2 is subject to further studies, especially in the clinic.

Optical coherence tomography angiography findings in patients with COVID-19.

OBJECTIVE: To examine the changes in choriocapillaris and retina caused by coronavirus disease 2019 (COVID-19) by comparing optical coherence tomography angiography (OCTA) findings of COVID-19 patients and healthy controls. METHODS: The study and control groups consisted of 54 eyes of 27 participants, each. Patients and controls underwent OCTA examination. Foveal zone vessel density and parafoveal zone vessel density (for 4 quadrants: nasal, temporal, superior, inferior) were calculated for both superficial and deep capillary plexuses. Additionally, choriocapillaris flow and foveal avascular zone areas were calculated. RESULTS: For the parafoveal area in the study group, vessel density was significantly lower in the superior and nasal quadrants of the superficial capillary plexus and in all quadrants of the deep capillary plexus compared with controls (p < 0.05 for all). The study group had significantly higher choriocapillaris flow area values compared with controls (p = 0.042). CONCLUSION: Reduced vessel density of the retinal capillary plexus was detected in COVID-19 patients who may be at risk for retinal vascular complications.