There have been a few rumours and talk about the wearing of contact lenses through this unprecedented period of the Covid-19 virus. Here is some of the extract from a detailed report that confirms there is not a risk of wearing contact lenses-just good hand hygiene as needed generally anyway-but thought this would provide some good information for those interested . If you have any particular query though do not hesitate to contact the practice for professional advice.
A PubMed search on April 5, 2020 found no evidence that contact lens wearers are more likely to contract COVID-19 than spectacle wearers. The likely belief for this concern relates to the fact that SARS-CoV-2 has been isolated in tears, albeit infrequently,5 and also that the virus is known to be transferred by hand contact, and thus could be transferred to contact lenses during their application and removal. In one report, positive tear and conjunctival secretions occurred in a single patient who developed conjunctivitis from a cohort of 30 patients with novel CoV pneumonia.5 In another report,6 64 samples of the tear film from 17 patients with COVID-19 showed no evidence of SARS-CoV-2 by viral culture or reverse transcriptase polymerase chain reaction (RT-PCR). Further, the frequency of conjunctivitis in patients with COVID-19 reported to date is low, at <3%,5,7 although it has been suggested that CoVs could possibly be transmitted by aerosol contact with the conjunctiva in patients with active disease.5,7-11 However, the question of whether COVID-19 can occur through conjunctival exposure remains unknown.12 Recent papers concluded that ‘The eye is rarely involved by human CoV infection, nor is it a preferred gateway of entry for human CoVs to infect the respiratory tract’13 and that ‘The results from this study suggests that the risk of SARS-CoV-2 transmission through tears is low’.6 Thus, to date, there are no findings that support concerns that healthy patients are more at risk of contracting COVID-19 if they are contact lens wearers.
It could be argued that COVID-19 is so new that such data would not yet exist. However, the lack of evidence from previous outbreaks of coronavirus disease, including SARS in 2002-2003, suggests that the risk of developing COVID-19 from contact lens wear is low. It is informative to consider viral diseases that are transmitted by direct contact and which could be used as a surrogate for evaluating the risks of COVID-19 in contact lens wearers. One such example is epidemic keratoconjunctivitis (EKC), caused by the non-enveloped DNA virus adenovirus. This disease is highly contagious, spreads rapidly through direct contact, accounts for 65-90% of viral conjunctivitis cases14 and has been implicated in actively transmitted disease in eye care clinics and other common healthcare settings where there is close contact between healthcare providers and patients.15-19 However, a review of the literature appears to show no increased risk for EKC in those wearing contact lenses versus non-lens wearers, with a reported frequency of 3-15% in contact lens wearers.18,20
SARS-CoV-2 spreads primarily via person-to-person contact through respiratory droplets produced when an infected person coughs or sneezes.21,22 However, it also could be spread if people touch an object or surface with virus present from an infected person, and then touch mucosal surfaces such as their mouth, nose or eyes.22-24 Given that contact lens wearers must touch their eyes when applying and removing their contact lenses, it is understandable this has been raised as a potential concern for increasing their risk of exposure to the virus. The consistent, unambiguous advice to protect individuals from the virus is to employ frequent handwashing with soap and water. The lipid envelope of the virus can be emulsified by surfactants such as those found in simple soap, which kills the virus.22,25 Best practice advice for contact lens wearers includes the same instructions that should be imparted under all situations, regardless of the COVID-19 pandemic. When using contact lenses, careful and thorough hand washing with soap and water followed by hand drying with unused paper towels (termed ‘kitchen roll’ in the United Kingdom) is paramount. For contact lens wearers, this should occur before every contact lens application and removal, and this process reduces the risks of infection and inflammatory responses and is highly effective.26 It follows that as long as contact lens wearers are using correct hand hygiene techniques, they should be limiting any virus transmission to their ocular surface, and indeed, as already stated, there is currently no evidence that they are at any higher risk of developing COVID-19 infection than non-wearers.
A further consideration is the length of time the virus is viable on different surfaces, and in turn, the potential for it to bind to contact lens materials. Addressing the former, a recent study showed that the aerosol and surface stability of both SARS-Cov-2 and its predecessor, SARS-CoV-1 (the viral strain associated with the prior SARS epidemic) was similar.27 Specifically, both viruses could be detected in aerosols for up to three hours, on cardboard for 24 hours, and on plastic and stainless steel for two to three days. The persistence of coronaviruses on inanimate surfaces such as plastic and silicone rubber surfaces has recently been published as a review, although the studies did not include SARS-CoV-2.28 To date, no studies have addressed whether SARS-CoV-2 binds to contact lens materials of any type and thus no knowledge exists of whether there are differences between contemporary materials (such as hydrogel and silicone hydrogel) or whether different periods of replacement have any impact.
A final consideration is that of contact lens disinfection. To date, no evidence exists of the ability of currently marketed contact lens solutions to disinfect SARS-CoV-2, and evidence concerning the ability of contemporary care solutions to disinfect viruses remains equivocal.29,30 Stretching back more than 30 years, contact lens care systems have been shown to be effective at inactivating both Herpes simplex and human immunodeficiency virus (HIV),31,32 particularly when a rub step was included,33 and a rub and rinse step has been found to more effectively remove virus from contact lenses compared to when no rubbing occurred.30 A recent paper showed that benzalkonium chloride could slow or halt adenovirus.34 Most modern lens care systems include a surfactant,35 and given that SARS-CoV-2 has a lipid envelope, it is plausible that a rub-and-rinse of the lens with such a care system may well be effective at killing the virus, but further work in this area is required to confirm this. Inactivation of coronaviruses by various biocidal agents, including some found in lens disinfecting solutions has been investigated. Significant reductions (>4log10) in human coronavirus were seen in 60 seconds or less for both 0.5% hydrogen peroxide and 0.23% povidone iodine, both being used at notably lower concentrations than that found in modern contact lens disinfection systems.28
Coronavirus and spectacle lens wear
Recent news reports have made a number of suggestions about spectacles, including that they can provide some protection against the virus, and that they reduce the number of times people touch their face compared to contact lenses. What does the published evidence to date tell us about this issue?
A systematic review of the literature shows there is no scientific evidence that wearing spectacles provides protection against SARS-CoV-2 or other viral transmissions, although this concept has been recently proposed in the media.36-38 This belief around the safety of spectacles likely exists because of the guidance to use approved personal protective eyewear (medical masks, goggles or face shields) in certain settings involved in the care of infected patients.39 However, these goggles and shields provide very different protection to that afforded by standard spectacles, a difference recognised by the US Centers for Disease Control and Prevention (CDC), who state that ‘personal eyeglasses and contact lenses are not considered adequate eye protection.’40
Despite the CDC’s clear delineation between standard spectacles and approved personal protective eyewear, it is understandable that a misplaced belief still exists for spectacles being preferable to contact lenses. There are a number of confounding factors, however, which do not support this theory. Consider firstly, part-time wearers of spectacles who only use their spectacles for occasional distance use or for reading. Their assumed ‘protection’ is intermittent, and additionally their increased frequency of putting on and removing their spectacles adds to the potential of touching their face each time, possibly in the absence of hand washing. Another point to consider is that some viruses such as SARS-CoV-2 can remain on hard plastic surfaces (similar to those found in spectacle frames and lenses) for hours to days.28,41-43 Upon touching their spectacles, any virus particles could be transferred to the wearers’ fingers and face and thus adequate hand hygiene practices should also extend to the regular handling of spectacle and sunglass frames to prevent transmission of viral particles to the fingers and subsequently to the face. Spectacles should be regularly cleaned with soap and water and dried with a paper towel to remove any adhered viral particles. However, given this is relatively new advice, without education, it is currently unlikely that spectacle wearers would adhere to such a process.
The importance of hand hygiene
Outside of contact lens and spectacle wear, how often do people touch their face in general, and what is the best advice to give them?
Hands are a common vector for the transmission of respiratory infections.44 An observational study of medical students examined the frequency with which they touched their face.45 On average, each of the students touched their face 23 times per hour. Of all face touches, 44% involved contact with a mucous membrane (eyes, nose or mouth) versus 56% that involved contact with non-mucosal areas (ears, cheeks, chin, forehead or ear). Of the mucous membrane touches, 36% involved the mouth, 31% the nose, 27% the eyes, and 6% were a combination of these regions. Given this very high number of face touches, hand washing becomes extremely important as a method to prevent transmission of any pathogenic organism from the fingers to the mucous membranes of the face. In relation to COVID-19, this advice, as recommended by the WHO and CDC, applies to everyone whether they use contact lenses, spectacles or no vision correction at all.
In addition to common soaps used in hand washing, the SARS-CoV-2 virus is very likely susceptible to the same alcohol and bleach-based disinfectants that eye care practitioners commonly use to disinfect ophthalmic instruments and office furniture.28 To prevent SARS-CoV-2 transmission, the same disinfection practices already used to prevent office-based spread of other viral pathogens are recommended before and after every patient encounter. Many of these steps have been summarised in a recent editorial,46 which covers a number of important considerations for conducting safe clinical practice during the pandemic.
The CDC and WHO recommend that people clean their hands often to reduce their risk of contracting the virus. Specifically, they advise all people to:
- Wash their hands often with soap and water for at least 20 seconds especially after they have been in a public place, or after blowing their nose, coughing, or sneezing.
- If soap and water are not readily available, they should use a hand sanitizer that contains at least 60% alcohol. They should cover all surfaces of their hands and rub them together until they feel dry.
- They should avoid touching their eyes, nose, and mouth with unwashed hands
- Scrupulous hand hygiene along with correct use of care solutions, including multipurpose solutions with appropriate rub and rinse cleaning of reusable lenses, daily case cleaning and regular replacement of the lens case are all positive changes about which eye care professionals should remind their patients at the current time. Likewise, an important point is to counsel on the avoidance of contact with water to reduce the risk of microbial keratitis, especially Acanthamoeba keratitis.64,65 Finally, and consistent with general advice, when a patient is unwell, particularly with an upper respiratory tract infection, this is the time to cease wearing contact lenses and return to spectacles. Contact lens wear can be resumed, with a fresh pair of lenses, and, if used, a fresh contact lens case, when they feel well again.
Adherence to compliant lens wear and care practices is an important aim for the profession all of the time, however, it can be argued during the current outbreak of SARS-CoV-2 this should be an area of heightened focus. The attention on thorough hand washing is welcome and an important start, but for eye care practitioners it is reasonable to use this time to go much further, revisiting patient education on safe wear and care practices with the aim of reducing the chance of developing contact lens-related complications requiring clinical care. Distilled from the evidence reviewed in the full paper,1 there are five key points that may be useful for eye care practitioners to communicate to patients (table 2).
Table 2: Information to communicate to contact lens and spectacle wearers
In addition to this, practitioners are advised to seek resources on patient-facing information to help remind them of safe wear and care practices, some of which can be found in a previous article in Contact Lens Spectrum,66 and in the UK, the BCLA has provided advice for practitioners and contact lens wearers.67 Information is also available through a number of professional organisations and contact lens manufacturers, with free downloadable content, including a handout containing the five tips related to COVID-19 and contact lens wearers, on CORE’s Contact Lens Update website.
Conclusions
In conclusion, to date no evidence suggests that contact lens wearers who are asymptomatic should cease contact lens wear due to an increased risk of developing COVID-19, advice which has been recently echoed by the CDC.68 There is no evidence that wearing prescription spectacles provides protection against SARS-CoV-2 or that any one form of contact lens material is more likely to enhance or reduce the risk of future COVID-19 infection.
Practitioners must remain vigilant about reminding contact lens wearers of the need to maintain good hand hygiene practices when handling lenses. A focus on fully compliant contact lens wear and especially on the modifiable risk factors associated with contact lens complications are important during the height of the pandemic, where access to primary and secondary optometric care may be substantially different to normal, and practitioners should act to minimise the burden on the wider healthcare system by considering their local clinical pathway options. Patients must be reminded of the need to dispose of daily disposable lenses upon removal, the need for appropriate disinfection with reusable lenses, including the use of a rub-and-rinse step where indicated and appropriate case cleaning and replacement. Finally, consistent with guidance for other types of illness, particularly those of the respiratory tract, no contact lens wearer with active COVID-19 should remain wearing their contact lenses. This is the time to cease contact lens wear and revert to spectacles.
This article was featured as a CET module in Optician. To complete the module online visit https://cet.opticianonline.net/Course/Information?courseId=5933
Lyndon Jones is Professor, School of Optometry & Vision Science and Director, Centre for Ocular Research & Education (CORE), University of Waterloo, Canada where Karen Walsh is Professional Education Team Leader and Clinical Scientist. Mark Willcox is Professor and Research Director, School of Optometry and Vision Science, UNSW, Australia. Philip Morgan is Professor of Optometry, Head of Optometry, Deputy Head of the Division of Pharmacy and Optometry, Director, Eurolens Research, The University of Manchester, UK. Jason Nichols is Associate Vice President for Research & Professor, Office of the Vice President for Research & School of Optometry, University of Alabama, U