Contact Lens Update

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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.

REFERENCES

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