Detection of SARS-CoV-2-RNA in post-mortem samples of human eyes

Abstract

Purpose To detect SARS-CoV-2 RNA in post-mortem human eyes. Ocular symptoms are common in patients with COVID-19. In some cases, they can occur before the onset of respiratory and other symptoms. Accordingly, SARS-CoV-2 RNA has been detected in conjunctival samples and tear film of patients suffering from COVID-19. However, the detection and clinical relevance of intravitreal SARS-CoV-2 RNA still remain unclear due to so far contradictory reports in the literature. Methods In our study 20 patients with confirmed diagnosis of COVID-19 were evaluated post-mortem to assess the conjunctival and intraocular presence of SARS-CoV-2 RNA using sterile pulmonary and conjunctival swabs as well as intravitreal biopsies (IVB) via needle puncture. SARS-CoV-2 PCR and whole genome sequencing from the samples of the deceased patients were performed. Medical history and comorbidities of all subjects were recorded and analyzed for correlations with viral data. Results SARS-CoV-2 RNA was detected in 10 conjunctival (50%) and 6 vitreal (30%) samples. SARS-CoV-2 whole genome sequencing showed the distribution of cases largely reflecting the frequency of circulating lineages in the Munich area at the time of examination with no preponderance of specific variants. Especially there was no association between the presence of SARS-CoV-2 RNA in IVBs and infection with the variant of concern (VOC) alpha. Viral load in bronchial samples correlated positively with load in conjunctiva but not the vitreous. Conclusion SARS-CoV-2 RNA can be detected post mortem in conjunctival tissues and IVBs. This is relevant to the planning of ophthalmologic surgical procedures in COVID-19 patients, such as pars plana vitrectomy or corneal transplantation. Furthermore, not only during surgery but also in an outpatient setting it is important to emphasize the need for personal protection in order to avoid infection and spreading of SARS-CoV-2. Prospective studies are needed, especially to determine the clinical relevance of conjunctival and intravitreal SARS-CoV-2 detection concerning intraocular affection in active COVID-19 state and in post-COVID syndrome.

Ocular tropism of SARS-CoV-2 in animal models with retinal inflammation via neuronal invasion following intranasal inoculation

“…In contrast, a cross-sectional study in Italy reported the presence of viral RNA in the conjunctival swabs of 52 of 91 patients with COVID-19, with a high rate of detection in patients with severe disease 6 . Other cross-sectional studies in China 7 and Brazil 8 , and post-mortem examinations 9,10 also reported viral RNA detection in conjunctival swabs or in the aqueous humour of patients with or without ocular manifestations.…”

Presence of SARS-CoV-2 on the conjunctival mucosa in patients hospitalized due to COVID-19: Pathophysiological considerations and therapeutic implications

“…In hospital settings SARS-CoV-2 can be also transmitted by virus carrying stuff or patients derived respiratory droplets [32] reaching the conjunctiva of patients. In addition, SARS-CoV-2 RNA has been detected post mortem in conjunctival tissues and intravitreal biopsies [33]. Thus the original entry of virus cannot always be ascertained.…”

Does SARS-CoV-2 affect neurodegenerative disorders? TLR2, a potential receptor for SARS-CoV-2 in the CNS

“…Recent studies demonstrated that the expression of ACE2 is relatively high in the corneal epithelium and suggested that ocular conjunctival inoculation was enough to cause COVID-19 49 , 50 . In addition, various sampling studies identified the presence of SARS-CoV-2 RNA within regions of the visual system, such as the retina, optic nerve, conjunctiva, and vitreous body, in patients with confirmed SARS-CoV-2 diagnoses 51 , 52 . A recent study revealed that the S protein of the novel coronavirus can cross the blood-brain barrier (BBB) 53 .…”