Karen Walsh is the Professional Education Team Leader and Clinical Scientist at the Centre for Ocular Research & Education, (CORE) based at the University of Waterloo, Canada. She has previously worked as a Professional Affairs Manager in the contact lens industry, and in clinical practice in the UK. She holds a post graduate diploma in Clinical Optometry from City University, London UK, and is a Fellow of the International Association of Contact Lens Educators and the British Contact Lens Association.
The risk factors associated with microbial keratitis (MK) and corneal inflammatory events (CIEs) in contact lenses are well understood, with a number of those identified risk factors being modifiable and associated with poor compliance.1-6 The pathogenesis of both MK and CIEs involves the presence of microorganisms, which can be found on the contact lens and are traceable back to the lid margins, conjunctiva, hands, lens case, care solution or water supply.5,7-10 This review was conducted to examine the question of whether patients’ unwashed hands are a primary source of microbial contamination.
Public health concern of hand hygiene
Hand washing is known to halt the spread of infection, and is effective in preventing the spread of some diseases.11 Organisations such as the World Health Organisation (WHO) recommend the benefits of this simple act, providing open access advice on best-practice handwashing techniques.12 However, rates of handwashing in the general population may be described as disappointingly low, with only about two-thirds of people practicing any sort of hand hygiene.13 In fact, around one-third of men, and one-fifth of women were observed not washing their hands after using the washroom in one study.11
The relationship between hand hygiene education and behaviour modification
Studies have shown that an intervention such as education, or promoting hand washing, can have a positive effect on changing behaviour and reducing infections,14,15 although the rate of hand washing decreases over time post the point of initial education,16,17 and is it hard to prove long-term behaviour change.18 Multiple interventions – reminders over time – are more effective than any single effort.19 An important finding is that there is a higher-risk in non-adherence by patients whose physician communicates information poorly.20
Hand washing behaviour of contact lens wearers
Up to 50% of contact lens wearers are not compliant with hand washing procedures.21-24 A recent survey of daily disposable contact lens wearers explored attitudes to hand washing and bacteria. Although 88% of wearers believed bacteria could transfer from their fingers to their eyes during contact lens insertion, this did not seem to encourage more of them to wash their hands. Within the same group, 41% did not wash their hands with soap prior to lens insertion, 15% rarely or never wash their hands or do so without soap, and nearly two-thirds did not use a sanitary option to dry their hands.13
Poor hand hygiene or absence of hand washing are known risk factors for MK and CIEs,6,25,26 with one study finding that 90% of the disease load was associated with wearers who did not wash their hands.26 Hand washing with soap is essential for contact lens wearers to minimise microbial contamination of their hands,27 and although conflicting reports exist showing the efficacy of hand washing in reducing bacterial load on contact lenses,28,29 the recommendation to include this step prior to touching lenses still remains.
Mitigating strategies of microbial contamination
The paper makes a clear recommendation that contact lens wearers should always undertake thorough hand washing with soap and water, followed by hand drying with an unused paper towel. This is the same method adopted by the WHO. What is not so well established is the efficacy of patient education programs in elevating, and maintaining, good hand hygiene practices in contact lenses wearers. More research would be welcome in this area. Daily disposables are mentioned as a good option to reduce repeated hand-lens interactions, along with novel ‘flat pack’ packaging designs which minimise the need to touch the posterior contact lens surface that is in close proximity with the ocular surface during wear.
Take away points
This review paper highlights the relevance of hand hygiene in maintaining safe contact lens wear, and makes clear recommendations on hand washing techniques that should be employed by all contact lens wearers. Education is important in helping the patient raise their compliance,30 but eye-care practitioners (ECP) need to remember that this advice needs to be repeated frequently – likely reinforced at every contact lens check. Finally, clear communication from the ECP is important in helping patients understand the need for good hand hygiene and to motivate them to maintain good practices.
- Schein OD, Glynn RJ, Poggio EC, Seddon JM, Kenyon KR. The relative risk of ulcerative keratitis among users of daily-wear and extended-wear soft contact lenses. A case-control study. Microbial Keratitis Study Group. The New England journal of medicine. 1989;321(12):773-778.
- Lam DS, Houang E, Fan DS, Lyon D, Seal D, Wong E. Incidence and risk factors for microbial keratitis in Hong Kong: comparison with Europe and North America. Eye. 2002;16(5):608-618.
- Dart JK, Radford CF, Minassian D, Verma S, Stapleton F. Risk factors for microbial keratitis with contemporary contact lenses: a case-control study. Ophthalmology. 2008;115(10):1647-1654, 1654 e1641-1643.
- Sauer A, Meyer N, Bourcier T, French Study Group for Contact Lens-Related Microbial K. Risk Factors for Contact Lens-Related Microbial Keratitis: A Case-Control Multicenter Study. Eye & contact lens. 2016;42(3):158-162.
- Stapleton F, Edwards K, Keay L, et al. Risk factors for moderate and severe microbial keratitis in daily wear contact lens users. Ophthalmology. 2012;119(8):1516-1521.
- Radford CF, Minassian D, Dart JK, Stapleton F, Verma S. Risk factors for nonulcerative contact lens complications in an ophthalmic accident and emergency department: a case-control study. Ophthalmology. 2009;116(3):385-392.
- Szczotka-Flynn LB, Pearlman E, Ghannoum M. Microbial contamination of contact lenses, lens care solutions, and their accessories: a literature review. Eye & contact lens. 2010;36(2):116-129.
- Jiang Y, Jacobs M, Bajaksouzian S, et al. Risk factors for microbial bioburden during daily wear of silicone hydrogel contact lenses. Eye & contact lens. 2014;40(3):148-156.
- Wu YT, Willcox M, Zhu H, Stapleton F. Contact lens hygiene compliance and lens case contamination: A review. Contact lens & anterior eye. 2015;38(5):307-316.
- Radford CF, Minassian DC, Dart JK. Acanthamoeba keratitis in England and Wales: incidence, outcome, and risk factors. The British journal of ophthalmology. 2002;86(5):536-542.
- https://globalhandwashing.org/resources/the-state-of-handwashing-in-2016/. Accessed 14 Mar 2020.
- https://www.who.int/gpsc/5may/Hand_Hygiene_Why_How_and_When_Brochure.pdf. Accessed 14 mar 2020.
- Fonn D, Jones L. Hand hygiene is linked to microbial keratitis and corneal inflammatory events. Contact lens & anterior eye. 2019;42(2):132-135.
- O’Reilly CE, Freeman MC, Ravani M, et al. The impact of a school-based safe water and hygiene programme on knowledge and practices of students and their parents: Nyanza Province, western Kenya, 2006. Epidemiol Infect. 2008;136(1):80-91.
- Ejemot-Nwadiaro RI, Ehiri JE, Arikpo D, Meremikwu MM, Critchley JA. Hand washing promotion for preventing diarrhoea. Cochrane Database Syst Rev. 2015(9):CD004265.
- Dubbert PM, Dolce J, Richter W, Miller M, Chapman SW. Increasing ICU staff handwashing: effects of education and group feedback. Infect Control Hosp Epidemiol. 1990;11(4):191-193.
- McGuckin M, Taylor A, Martin V, Porten L, Salcido R. Evaluation of a patient education model for increasing hand hygiene compliance in an inpatient rehabilitation unit. American journal of infection control. 2004;32(4):235-238.
- Vindigni SM, Riley PL, Jhung M. Systematic review: handwashing behaviour in low- to middle-income countries: outcome measures and behaviour maintenance. Trop Med Int Health. 2011;16(4):466-477.
- Cherry MG, Brown JM, Bethell GS, Neal T, Shaw NJ. Features of educational interventions that lead to compliance with hand hygiene in healthcare professionals within a hospital care setting. A BEME systematic review: BEME Guide No. 22. Med Teach. 2012;34(6):e406-420.
- Zolnierek KB, Dimatteo MR. Physician communication and patient adherence to treatment: a meta-analysis. Medical care. 2009;47(8):826-834.
- Yung AM, Boost MV, Cho P, Yap M. The effect of a compliance enhancement strategy (self-review) on the level of lens care compliance and contamination of contact lenses and lens care accessories. Clinical & experimental optometry. 2007;90(3):190-202.
- Radford C, Woodward E, Stapleton F. Contact lens hygiene compliance in a university population. J Brit Contact Lens Assoc. 1993;16(3):105-111.
- Morgan PB, Efron N, Toshida H, Nichols JJ. An international analysis of contact lens compliance. Contact lens & anterior eye. 2011;34(5):223-228.
- Sokol JL, Mier MG, Bloom S, Asbell PA. A study of patient compliance in a contact lens-wearing population. The CLAO journal : official publication of the Contact Lens Association of Ophthalmologists, Inc. 1990;16(3):209-213.
- Lim CH, Carnt NA, Farook M, et al. Risk factors for contact lens-related microbial keratitis in Singapore. Eye (Lond). 2016;30(3):447-455.
- Stapleton F, Naduvilath T, Keay L, et al. Risk factors and causative organisms in microbial keratitis in daily disposable contact lens wear. PloS one. 2017;12(8):e0181343.
- Pittet D, Dharan S, Touveneau S, Sauvan V, Perneger TV. Bacterial contamination of the hands of hospital staff during routine patient care. Archives of internal medicine. 1999;159(8):821-826.
- Mowrey-McKee MF, Sampson HJ, Proskin HM. Microbial contamination of hydrophilic contact lenses. Part II: Quantitation of microbes after patient handling and after aseptic removal from the eye. The CLAO journal : official publication of the Contact Lens Association of Ophthalmologists, Inc. 1992;18(4):240-244.
- Ly V, Simmons P, Edrington T, Wechsler S, De Land P. Efficacy of hand washing procedures on bacterial contamination of hydrogel contact lenses. Optometry and vision science. 1997;74(5):288-292.
- McMonnies CW. Hand hygiene prior to contact lens handling is problematical. Contact lens & anterior eye. 2012;35(2):65-70.