Occurrence of SARS-CoV-2 in the intraocular milieu

Acute angle-closure glaucoma before, during, and after the outbreak of COVID-19 in China

Objectives

Acute angle-closure glaucoma (AACG) is a major cause of irreversible and severe visual function loss. Robust rise in AACG was observed in the ophthalmic outpatient clinics concomitant with the outbreak of COVID-19 infection in China after the relaxing of "zero-COVID policy" in early December 2022. Here we compared the demographic and clinical profiles of patients with AACG before, during and after the COVID-19 outbreak. Underlying mechanisms were tentatively investigated.

Methods

This is a retrospective comparative study. Consecutive cases with newly diagnosed AACGs in a tertiary eye hospital were retrospectively collected during December 17, 2022 to January 8, 2023. Data from the same period in 2018-2019 and 2019-2020, 2020-2021 and 2021-2022, and 2023-2024 were collected as pre-pandemic, pandemic-control, and post-pandemic control, respectively. For the patients in 2022-2023 outbreak group, COVID-19 infection was confirmed by reversed transcriptase-polymerase chain reaction or antibody test for severe acute respiratory syndrome coronavirus disease 2 (SARS-CoV-2) from nasopharyngeal swabs. Ocular parameters, serum electrolytes and coagulative parameters were compared between COVID-19 positive and negative AACGs in observational group. SARS-CoV-2 nucleic acid in the aqueous humor was detected.

Results

A total of 106 AACG cases were diagnosed during the outbreak period in 2022-2023. In contrast, 18 (in 2018-2019) and 22 (in 2019-2020) cases were included during pre-pandemic period, and 21 (in 2023-2024) during the post-pandemic period. Only 13 and 4 newly onset AACG were included in 2020-2021 and 2021-2022 during the pandemic-control period, respectively. Younger age and higher proportion of bilateral involvement were detected in COVID-19 outbreak group than that of other groups (p = 0.034 and p = 0.080). Sixty-eight (64.2 %) patients in the outbreak group had a confirmed COVID-19 infection. Intervals between infection and AACG attack was 52 ± 85h (0-15d). Fifty-three patients (77.9 %) reported the applications of ibuprofen or other antipyretic medications and 25 (36.8 %) reported large volume water intake before AACG attack. COVID-19-positive AACG patients had higher level of D-dimer than their negative counterparts (1.13 ± 2.60 mg/L vs. 0.46 ± 0.43 mg/L, p = 0.083). No difference in IOP, serum electrolytes, and coagulative parameters other than D-dimer was observed between COVID-19 positive and negative cases. SARS-CoV-2 were negative in the aqueous humor from 14 COVID-19 positive and 8 negative patients.

Conclusion

COVID-19 infection surged the onset of AACG in patients at risk. Mental stress, water intake, increased choroidal thickness due to SARS-CoV-2 induced ACE receptor activation, and hyper-coagulation, may contribute to the disease onset. Ocular involvement should not be ignored in both routine and new systemic emergent conditions.

SARS-CoV-2 persistence and infectivity in COVID-19 corpses: a systematic review

The persistence and infectivity of SARS-CoV-2 in different postmortem COVID-19 specimens remain unclear despite numerous published studies. This information is essential to improve corpses management related to clinical biosafety and viral transmission in medical staff and the public community. We aim to understand SARS-CoV-2 persistence and infectivity in COVID-19 corpses. We conducted a systematic review according to Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) protocols. A systematic literature search was performed in PubMed, Science Direct Scopus, and Google Scholar databases using specific keywords. We critically reviewed the collected studies and selected the articles that met the criteria. We included 33 scientific papers that involved 491 COVID-19 corpses. The persistence rate and maximum postmortem interval (PMI) range of the SARS-CoV-2 findings were reported in the lungs (138/155, 89.0%; 4 months), followed by the vitreous humor (7/37, 18.9%; 3 months), nasopharynx/oropharynx (156/248, 62.9%; 41 days), abdominal organs (67/110, 60.9%; 17 days), skin (14/24, 58.3%; 17 days), brain (14/31, 45.2%; 17 days), bone marrow (2/2, 100%; 12 days), heart (31/69, 44.9%; 6 days), muscle tissues (9/83, 10.8%; 6 days), trachea (9/20, 45.0%; 5 days), and perioral tissues (21/24, 87.5%; 3.5 days). SARS-CoV-2 infectivity rates in viral culture studies were detected in the lungs (9/15, 60%), trachea (2/4, 50%), oropharynx (1/4, 25%), and perioral (1/4, 25%) at a maximum PMI range of 17 days. The SARS-CoV-2 persists in the human body months after death and should be infectious for weeks. This data should be helpful for postmortem COVID-19 management and viral transmission preventive strategy.

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

Although ocular manifestations are reported in patients with COVID-19, consensus on ocular tropism of SARS-CoV-2 is lacking. Here, we infect K18-hACE2 transgenic mice with SARS-CoV-2 using various routes. We observe ocular manifestation and retinal inflammation with production of pro-inflammatory cytokines in the eyes of intranasally (IN)-infected mice. Intratracheal (IT) infection results in dissemination of the virus from the lungs to the brain and eyes via trigeminal and optic nerves. Ocular and neuronal invasions are confirmed using intracerebral (IC) infection. Notably, the eye-dropped (ED) virus does not cause lung infection and becomes undetectable with time. Ocular and neurotropic distribution of the virus in vivo is evident in fluorescence imaging with an infectious clone of SARS-CoV-2-mCherry. The ocular tropic and neuroinvasive characteristics of SARS-CoV-2 are confirmed in wild-type Syrian hamsters. Our data can improve the understanding regarding viral transmission and clinical characteristics of SARS-CoV-2 and help in improving COVID-19 control procedures.

SARS-CoV-2 RNA Detected in Vitreous Samples Obtained at Autopsy

Purpose

This work aims to examine the vitreous of autopsy patients with COVID-19 for the presence of SARS-CoV-2 RNA.

Methods

Four deceased patients with COVID-19 had an autopsy at Massachusetts General Hospital. Two control specimens were obtained from patients undergoing retinal detachment repair with negative preoperative polymerase chain reaction (PCR) testing for SARS-CoV-2 RNA. Vitreous specimens were obtained from autopsy patients with COVID-19 after povidone was placed on the ocular surface to decrease the risk of contamination of the vitreous specimen. SARS-CoV-2 RNA for gene N (nucleocapsid) was tested using reverse transcription-PCR.

Results

SARS-CoV-2 RNA was detected in the vitreous of 2 of 4 autopsy patients who died from complications of COVID-19.

Conclusions

SARS-CoV-2 RNA can penetrate into the vitreous of systemically infected patients, which might present risks to operating room personnel during ophthalmic surgical procedures.

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

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.

Presence of SARS-CoV-2 Viral RNA in Aqueous Humor of Asymptomatic Individuals

PURPOSE

The purpose of this study was to determine whether severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is detectable in the aqueous of asymptomatic individuals presenting for ophthalmic surgery.

DESIGN

Prospective cross-sectional study.

METHODS

Setting and participants: all patients undergoing anterior segment surgery at an ambulatory surgical center (ASC) belonging to a tertiary academic center in South Florida during a 102-day period between June and September 2020 received nasal swab testing for SARS-CoV-2 and underwent a relevant review of symptoms prior to surgery, with negative results required for both in order to proceed with surgery. Main outcomes and measurements: a small sample of aqueous humor (approximately 0.2 cc) was acquired at the beginning of anterior segment surgery from all participants. Aqueous humor was analyzed for SARS-CoV-2 viral ribonucleic acid (RNA) using real-time reverse transcriptase polymerase chain reaction. Demographic information was acquired from participants for secondary analyses.

RESULTS

A total of 70 samples were acquired. Of those, 39 samples were excluded due to insufficient material or inconclusive results. Of 31 samples that were successfully analyzed, 6 (19.4%) demonstrated detectable SARS-CoV-2 RNA. None of the 6 individuals (0%) with detectable viral RNA in aqueous humor reported symptoms during the year, compared to 2 of 25 individuals (8%) with negative samples (P = 1). Positive samples were distributed throughout the study period, including both the first and the last days of enrollment.

CONCLUSIONS

The presence of SARS-CoV-2 viral RNA in aqueous despite negative nasal swab testing confirmed its presence beyond the blood-ocular barrier in asymptomatic individuals and raises the possibility that the virus may persist in immunoprivileged spaces despite an absence of symptoms.

Evaluating the presence of SARS-CoV-2 in the intraocular fluid of COVID-19 patients

PURPOSE

To detect the presence of SARS-CoV-2 in aqueous and vitreous humor of COVID-19 patients in a pilot study.

METHODS

: Consecutive patients planned for emergency ophthalmic surgeries after ocular trauma were subjected to naso-oropharyngeal RT-PCR test for SARS-CoV-2. Laboratory-confirmed cases were enrolled for the study. During surgery, 0.1 mL aqueous and vitreous each was aspirated. The vitreous tap was collected on clinical suspicion of endophthalmitis. RT-PCR test was used to detect SARS-COV-2 nucleotide in the samples. Cycle threshold (Ct) for E gene of ≤35 along with confirmatory results on one of the two target genes (RdRp or ORF1b) was considered as positive.

RESULTS

: One hundred and thirty two patients were found positive on naso-oropharyngeal RT-PCR test for SARS-CoV-2 preoperatively. Seven patients with ocular trauma were studied. The mean age was 31.8 years. There were six male and one female patient. Two patients had symptoms of mild COVID-19 disease and the rest were asymptomatic. The mean Ct value of the E gene on naso-oropharyngeal RT-PCR was 23.14 ± 4.7. Corneal and corneoscleral laceration repair was done in five patients, intracorneal wooden foreign body was removed in one patient, and injection of intravitreal antibiotics was done in one patient. Aqueous and vitreous tap was collected in 7 and 5 patients, respectively. None of the aqueous or vitreous samples was found positive for SARS-CoV-2.

CONCLUSION

: SARS-CoV-2 was not detected by RT-PCR in aqueous or vitreous humor in this pilot study. Future studies with a larger sample size are needed to further explore the presence of SARS-CoV-2 in intraocular fluids.

Pathology of the Brain and the Eye in Severe Acute Respiratory Syndrome Coronavirus-2-Infected Patients: A Review

BACKGROUND

Patients with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) may present or eventually develop central nervous system and ophthalmic signs and symptoms. Varying reports have emerged regarding isolation of viral RNA from these tissue sites, as well as largely autopsy-based histopathologic descriptions of the brain and the eye in patients with COVID-19.

EVIDENCE ACQUISITION

A primary literature search was performed in literature databases such as PubMed, Google Scholar, and Cochrane Library. Keywords were used alone and in combination including the following: SARS CoV-2, COVID-19, eye, brain, central nervous system, histopathology, autopsy, ocular pathology, aqueous, tears, vitreous, neuropathology, and encephalitis.

RESULTS

The reported ophthalmic pathologic and neuropathologic findings in patients with SARS-CoV-2 are varied and inconclusive regarding the role of direct viral infection vs secondary pathology. The authors own experience with autopsy neuropathology in COVID-19 patients is also described. There is a particular paucity of data regarding the histopathology of the eye. However, it is likely that the ocular surface is a potential site for inoculation and the tears a source of spread of viral particles.

CONCLUSIONS

Additional large postmortem studies are needed to clarify the role of SARS-CoV in the ophthalmic and neuropathologic manifestations of COVID-19.

Role of Reverse Transcriptase Polymerase Chain Reaction in Cornea Donors During the COVID-19 Pandemic

PURPOSE

The purpose of this study was to report the analysis of reverse transcriptase polymerase chain reaction (RT-PCR) of nasopharyngeal (NP) samples of cornea donors dying because of causes unrelated to severe acute respiratory coronavirus (SARS-CoV-2).

METHODS

A retrospective analysis of all cornea donors dying from causes other than SARS-CoV-2 between August 2020 and December 2020 was performed. Informed consent was obtained from the next of kin of the deceased for RT-PCR testing from NP swabs. Rapid antigen testing from all the deceased was performed before in situ cornea excision. In addition, NP samples in viral transport media for RT-PCR were also collected for SARS-CoV-2 analysis. Corneas were released from the eye bank only after a negative RT-PCR report.

RESULT

One hundred eighteen corneas from 59 donors were obtained by the eye bank. Eleven donors (18.64%) were positive for SARS-CoV-2 on RT-PCR testing. Six of these 11 donors had a Ct value of E gene less than 25.

CONCLUSIONS

NP samples of cornea donors dying due to causes other than coronavirus disease-19 were positive for SARS-CoV-2 on RT-PCR. This implicates that donors could be having asymptomatic/undetected coronavirus disease infection. We recommend adding the routine testing of NP samples of all cornea donors in the eye banking protocol in this ongoing SARS-CoV-2 pandemic.

Bilateral Acute Anterior Uveitis and Corneal Punctate Epitheliopathy in Children Diagnosed with Multisystem Inflammatory Syndrome Secondary to COVID-19

Purpose: To report bilateral anterior uveitis and corneal punctate epitheliopathy in children with multisystem inflammatory syndrome (MIS-C) secondary to coronavirus disease (COVID-19).Participants and methods: Five patients who were positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies and diagnosed with MIS-C were evaluated. Ophthalmologic examinations were performed in order to reveal ocular findings in MIS-C disease.Results: Slit lamp examinations showed bilateral non-granulomatous acute anterior uveitis in all patients and severe corneal punctuate epitheliopathy in three of the patients. These ocular findings mostly disappeared with treatment in about one week.Conclusion: Bilateral non-granulomatous acute anterior uveitis and dry eye can be detected in patients diagnosed with MIS-C secondary to COVID-19. Even if generally, COVID-19 is not a life threatening disease in children by itself, inflammatory ocular manifestations can be detected in MIS-C secondary to COVID-19.

Detection of SARS-CoV-2 genomic and subgenomic RNA in retina and optic nerve of patients with COVID-19

Purpose

Presence of SARS-CoV-2 RNA in human retinal biopsies (RBs) was previously reported by us. In this consecutive study, we analysed RB and optic nerve biopsies (ONBs) in deceased patients with confirmed COVID-19 assessing viral RNA load, possible virus replication and infectivity.

Patients and methods

In this case series, 14 eyes of 14 deceased patients with COVID-19 were enucleated during autopsy. RB and ONB were subjected to molecular detection of viral RNA, virus cultivation and immunohistochemistry. SARS-CoV-2 RNA loads were compared with RNA loads in the respective throat swabs, vitreous humour and blood samples.

Results

SARS-CoV-2 RNA was detected in 7/14 RBs and in 10/13 ONBs. While virus isolation failed and immunohistochemistry of SARS-CoV-2 spike protein was negative, subgenomic RNA (sgRNA) was detectable (40% RB; 60% ONB).

Conclusion

SARS-CoV-2 RNA is detectable in RB and ONB of patients with COVID-19. Presence of sgRNA could point to a SARS-CoV-2 infection of neuronal tissue, but as virus isolation failed and immunohistochemistry of SARS-CoV-2 spike protein was negative, an active infection seems unlikely.

Case Report: Post-mortem Histopathological and Molecular Analyses of the Very First Documented COVID-19-Related Death in Europe

In Europe, the first case of coronavirus disease (COVID-19) and the first COVID-19-related death were reported in France on January 24th and February 15th, 2020, respectively. Officially, the first case of COVID-19 infection in the Republic of Serbia was registered on March 6th. Herein, we presented the first case of retrospective detection of the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) in the post-mortem-obtained vitreous humor (VH), which took place on February 5th, 2020. This is the first death in Europe proven to be caused by COVID-19 by means of post-mortem histopathological and molecular analyses. Based on this finding, it appears that SARS-CoV-2 has been spreading faster and started spreading much earlier than it had been considered and that COVID-19 was probably the cause of the much-reported pneumonia of unknown origin in January and February 2020.