Eyeworld

112 | EYEWORLD | DECEMBER 2020 C ORNEA References 1. Sawant OB, et al. Prevalence of SARS-CoV-2 in human post-mor- tem ocular tissues. Ocul Surf. 2020. Online ahead of print. 2. Desautels JD, et al. Risks posed to corneal transplant recipients by COVID-19-affected donors. Ophthalmol Ther. 2020;9:371– 379. 3. Sun Y, et al. Mechanism of the action between the SARS-CoV S240 protein and the ACE2 re- ceptor in eyes. Int J Ophthalmol. 2006;6:783–786. Relevant disclosures Chamberlain: None Chan: None Corcoran: None DeMatteo: None Contact Chamberlain: chamberw@ohsu.edu Chan: clarachanmd@gmail.com Corcoran: Kevin@restoresight.org DeMatteo: Jennifer@restoresight.org risks. "We do need to look carefully in our corneal recipient populations for emergence of COVID after transplantation to see if we can correlate donor risk factors with recipient infec- tion," Dr. Chamberlain said. "Improved testing with better sensitivity and specificity may give us higher levels of confidence when donors have some risk factors for exposure or signs of respiratory illness. We certainly have to balance our caution to prevent disease transmission with the disposal of safe tissue, which could restore vision in our patients." Overall, Mr. Corcoran said the pandemic has illustrated that some challenges are bet- ter addressed collectively and collaboratively among eye banks, rather than individually. "[M]any eye banks shared their resources with other banks and with the transplant and healthcare partners in their communities. I think that this spirit will continue to grow within our membership," he said. Dr. Chamberlain reiterated in his follow-up email to EyeWorld that while the evidence for SARS-CoV-2 transmission in corneal tissue seems low, there are concerning theoretical continued from page 111 Update on COVID-19 and the eye EyeWorld provided early updates on the research that was coming out of the pandemic regarding the ocular effects, manifestations, and transmission possibilities of SARS-CoV-2. There are now hun- dreds of peer-reviewed papers published on the topic. A systematic literature review published in PLoS One identified 16 studies representing more than 2,300 confirmed COVID-19 cases. 1 This data showed that 11.6% of these patients had ocular surface manifestations of COVID-19, including ocular pain, discharge, redness, and follicular conjunctivitis. This study also reported viral RNA in 3.5% of ocular samples analyzed. The study authors noted that most published studies on the topic show "significant publication bias and heterogeneity." A prospective case series of 32 patients who were positive for COVID-19 evaluated tear and conjunc- tival samples, collected via swab and analyzed with RT-PCR. 2 It found 16% of samples in patients, who did not exhibit conjunctivitis or other ocular symptoms, had viral RNA. Dr. Chamberlain noted a 2003 paper that presented a lower sensitivity of RT-PCR in tear samples, which could mean that rates of ocular infections could be underestimated. 3 The role of ocular tissue in transmission of SARS-CoV-2 is likely low, a different systematic literature review concluded, though the eye as an infection route is a possibility. 4 One study did show the infec- tion of monkeys with SARS-CoV-2 through an ocular route that later developed into the respiratory disease. 5 A study that looked at replication of different viruses in the cornea found that while HSV and Zika do replicate in the cornea, SARS-CoV-2 does not. 6 In human corneal explants, SARS-CoV-2 did not replicate at all, according to the authors. "In addition to an antiviral role for IFNλR1 in the cornea, our results suggest that the human cornea does not support SARS-CoV-2 infection despite expression of ACE2, a SARS-CoV-2 receptor, in the human corneal epithelium," the authors concluded. References 1. Aggarwal K, et al. Ocular surface manifestations of coronavirus disease 2019 (COVID-19): A systematic review and meta-analysis. PLoS One. 2020;15:e0241661. 2. Kaya H, et al. Detection of SARS-CoV-2 in the tears and conjunctival secretions of Coronavirus disease 2019 patients. J Infect Dev Ctries. 2020;14:977–981. 3. Peiris JSM, et al. Coronavirus as a possible cause of severe acute respiratory syndrome. Lancet. 2003;361:1319–1325. 4. Peng M, et al. The role of the ocular tissue in SARS-CoV-2 transmission. Clin Ophthalmol. 2020;14:3017–3024. 5. Wei D, et al. Ocular conjunctival inoculation of SARS-CoV-2 can cause mild COVID-19 in rhesus macaques. Nat Commun. 2020;11:4400. 6. Miner JJ, et al. HSV-1 and Zika virus but not SARS-CoV-2 replicate in the human cornea and are restricted by corneal type III interferon. Cell Rep. 2020;33:108339.

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