The safe handling of contact lens products depends on good product use instructions and is an issue that is only slowly being recognised by manufacturers and regulatory bodies.
The safety and effectiveness of contact lens products, including patient hygiene, is a complex issue and one that involves more than the formulation of the solution itself.
Contact lens hygiene has long been recognised as vital to the prevention of contact-lens associated infection and inflammation. Recent research has shown that one in three eye health problems suffered by lens wearers are a direct result of improper lens care and cleaning1. In the Australian and New Zealand Microbial Keratitis Study2, significant associations were identified between the incidence of microbial keratitis (MK) and lens hygiene practices, as well as smoking, overnight wear, and male gender. This confirms earlier published case reports of infection with daily disposable and silicone hydrogel lenses, which have also highlighted the importance of lens and case cleaning3,4,5 (as well as smoking,6,7 and male gender4).
At the same time, patient studies such as that conducted by Morgan8, show that lack of compliance with hygiene and other lens care instructions is a widespread issue. His survey of contact lens use in Europe found that only 0.3 per cent of daily wearers and 2.7 per cent of extended wearers were fully compliant for all 14 steps identified for correct lens care. Many wearers stretched the use of their contact lens products by using lenses for too many days, sleeping in lenses when daily wear use only had been prescribed, sleeping in lenses for too many nights in the case of extended wear, and topping up solutions rather than discarding each time. Only a minority of wearers in the study cared for their contact lens case correctly, and as this is a known risk factor for ocular infection, there is clearly a need for better patient education in the use of contact lens cases. Similarly, a survey by the Contact Lens Council9 found that 44 per cent of patients always or occasionally topped up their contact lens solution, and 54 per cent did not clean their lens case after each use.
eye care professionals must reinforce lens care regimens with their patients
Living in the real world
So we know that contact lens hygiene and compliance is important to preventing infection. And we know that patients are not necessarily compliant. Any eyecare practitioner knows that patients can become complacent, and thus non-compliant with lens care instructions. They can also misunderstand instructions, or not remember the warnings and instructions practitioners have given them.
But while all this might seem obvious, patient non-compliance is something that is only slowly being recognised by manufacturers and regulatory bodies.
At the 111th meeting of the U.S. Food and Drug Administration (FDA) Ophthalmic Devices Panel of the Medical Devices Advisory Committee on 10 June 2008, Dr. Bernard Lepri, an FDA safety official, explained the ‘new’ idea of human factors engineering.
“The goal of ‘human factors engineering’ is to make products safe, efficient and easy to learn and use, by understanding how the consumer uses the product in the real world. What was once called ‘user error’ is now called ‘use error’ to spread the blame for misuse to include design and labelling. From this point of view, the manufacturer has the responsibility to reduce use error through proper design, testing, and labelling.
“Human factors engineering is especially challenging for contact lenses and lens care products. Common use errors with contact lenses include irregular cleaning of lenses, poor hand hygiene, using tap water or saliva to wet lenses, not following replacement schedules, lack of regular eye exams, and irregular replacement of disinfecting solutions,” said Dr. Lepri.
Dr. Lepri made the following recommendations: that labelling provide written instructions as well as reasons for the various procedural steps and the consequences of not following them; that eye care professionals must reinforce lens care regimens with their patients; that care product design and testing be consistent with consumer use patterns; and that product labelling include a discard date for use after opening the product.
The theme of working in the real world was continually revisited during presentations at the FDA meeting.
The Contact Lens Institute, an association of manufacturers, is developing a user-friendly cautionary product statement to communicate the importance of patient compliance. Dr. John Lally, Vice-President of AMO, said that pre-clinical testing should incorporate real-life elements accounting for properties of different lenses and patient non-compliance. Dr. Louise Sclafani, Chair of the American Optometric Association’s Contact Lens and Cornea Section, advocated improved labelling and the strengthening of pre-market testing to reflect more realistic conditions.
The Panel concluded that the current Regimen test should be revised to improve predictability of real world performance, including testing a lens in the case with the solution, no-rub, no-rinse and with biofilm. They also recommended that a realistic rub and rinse time should be included in labelling, along with explanations of why to rub and rinse.
Every little bit helps
Of course, the practitioner’s role in educating patients and providing patient care will remain crucial to maintaining and protecting patient eye health. But the ‘real world’ measures now being advocated in testing and labelling will be of tremendous support in getting the best possible outcomes for our patients.
Professor Brien Holden, BAppSc PhD DSc OAM, is CEO and Director of the Institute for Eye Research, CEO of the Vision Cooperative Research Centre, founder and Director of the Cornea and Contact Lens Research Unit at the School of Optometry and Vision Science, University of New South Wales, and was Director of the Cooperative Research Centre for Eye Research and Technology.