Health advice about the novel coronavirus (SARS-CoV-2) that causes the respiratory disease, COVID-19, is changing rapidly as scientists learn more about the characteristics of the virus. SARS-CoV-2 has been found in the tear and conjunctival secretions of one patient with COVID-19 pneumonia and concurrent conjunctivitis, but was absent in 29 other COVID-19 pneumonia patients without conjunctivitis.1 In a larger study of 1,099 COVID-19 patients, only nine (0.8%) had conjunctival congestion.2 These studies suggest SARS-CoV-2 can cause conjunctivitis, although cases are very rare.
ADVICE FOR CL WEARERS
Advice to all contact lens wearers when ill with cold/flu/COVID-19 should be to cease wear until at least 24 hours after symptoms resolve. It is well established that ‘strep throat’ (and colonisation of contact lenses by other bacteria in addition to Streptococcus) is associated with increased risk of contact lens associated inflammation.3,4 In addition to the risk of microorganism transmission to contact lenses while ill, there is the dampened immune response while fighting the infection, that may increase the risk of inflammatory events.
If contact lens wearers are well, they do not need to interrupt wear as long as they practise basic hygiene. This involves washing hands with soap and running water prior to any contact lens handling, including touching the eye. If soap and water are not available, the next best alternative is to use a 60% alcohol hand sanitiser. In both cases, the WHO method covering all hand surfaces and lasting 20–30 seconds is essential.
For contact lens wearers, extra attention should be given to tips of fingers and thumbs which touch the lenses. SARS-CoV-2 can survive on surfaces so it is important to be particularly careful after travelling on public transport for example. An important point to emphasise is that SARS-CoV-2 is a virus enveloped in fat. This means that soap will repel the virus and break down the coating.5 Alcohol 60% is also effective against coronavirus within 30 second exposure.6 It is imperative after washing hands with soap to rinse the virus off with running water and dry with a clean paper towel. The Centre for Disease Control, in the US, has a video which highlights scenarios when it is difficult to follow prescribed hand hygiene.
Contact lens wearers washing hands before touching lenses is something practitioners might take for granted. However a recent survey of over 950 daily disposable wearers in the US, found 44% did not wash hands before lens insertion.7 Stapleton et al, found that the microbial keratitis severe and moderate disease load in daily disposable wearers can be halved by washing hands.8
Not only is this COVID-19 situation a good opportunity to revisit hand hygiene, it is a chance to re-educate on other aspects of healthy contact lens wear.
These include:
- One time wear of daily disposables,
- Disinfecting re-usable contact lenses after each wear (following manufacturers’ guidelines),
- Avoiding water exposure to contact lenses,
- Maintaining contact lens case hygiene and timely disposal, and
- Avoiding overnight wear unless prescribed.
Dr Nicole Carnt is a Scientia Fellow and Senior Lecturer at the School of Optometry and Vision Science, University of New South Wales, Sydney.
References
- Xia J, Tong J, Liu M, Shen Y, Guo D. Evaluation of coronavirus in tears and conjunctival secretions of patients with SARS-CoV-2 infection. J Med Virol. 2020.
- Guan WJ, Ni ZY, Hu Y, Liang WH, Ou CQ, He JX, et al. Clinical Characteristics of Coronavirus Disease 2019 in China. N Engl J Med. 2020.
- Sankaridurg PR, Sharma S, Willcox M, Sweeney DF, Naduvilath TJ, Holden BA, et al. Colonization of hydrogel lenses with Streptococcus pneumoniae: risk of development of corneal infiltrates. Cornea. 1999;18(3):289-95.
- Sankaridurg PR, Sharma S, Willcox M, Naduvilath TJ, Sweeney DF, Holden BA, et al. Bacterial colonization of disposable soft contact lenses is greater during corneal infiltrative events than during asymptomatic extended lens wear. J Clin Microbiol. 2000;38(12):4420-4.
- Conley L, Tao Y, Henry A, Koepf E, Cecchini D, Pieracci J, et al. Evaluation of eco-friendly zwitterionic detergents for enveloped virus inactivation. Biotechnol Bioeng. 2017;114(4):813-20.
- Kampf G. Efficacy of ethanol against viruses in hand disinfection. J Hosp Infect. 2018;98(4):331-8.
- Fonn D, Jones L. Hand hygiene is linked to microbial keratitis and corneal inflammatory events. Contact lens & anterior eye : the journal of the British Contact Lens Association. 2019;42(2):132-5.
- Stapleton F, Naduvilath T, Keay L, Radford C, Dart J, Edwards K, et al. Risk factors and causative organisms in microbial keratitis in daily disposable contact lens wear. PloS one. 2017;12(8):e0181343.
