Since contact lenses (CLs) gained popularity and worldwide appeal as an alternative to spectacle wear, maintenance of the ocular health of those using them has been a concern. One of the most significant factors is compliance with practitioner and manufacturer recommendations.

The best chance to maintain ocular health in conjunction with CL wear is to maintain compliance across several issues. Replacement schedule, cleaning and disinfection, lens handling, hand washing, and water exposure are key issues.

To examine these issues, patient noncompliance and nonadherence have been studied extensively over the past 40 years. Noncompliance in CL practice has been reported to range from 40% to 91%.¹ It is worthwhile to review the literature and update providers as to what might have improved as of late, and what still might be of concern.

PATIENT AGE

CL wearers less than 25 years old have been reported to be at a greater risk for corneal infiltrative events.² In 2011, the Contact Lens Assessment in Youth (CLAY) study group developed the CLAY Contact Lens Risk Survey to identify risk factors for CL complications.² This instrument has been invaluable to identify the issues that face our younger patient base. The frequency of many noncompliant behaviors has been highly associated with age, with the highest percentage reported by 15- to 25-year-olds.²

Conversely, a younger group of patients (9 to 13 years of age) is actually at lower risk.^2,3 Greater parental involvement and living away from home can contribute to the disparity of approach to lens wear in these age groups.

In university-age wearers, CL noncompliant behaviors like napping, sleeping, and showering are common.^2,4 Alcohol consumption has also been linked. Nearly 1 in 4 university-age wearers were reported to share lenses and lens products with friends and roommates without any guidance or direction from an eyecare provider.² Living in close quarters without attention to cleanliness and levels of contamination in bathrooms, desks, doorknobs, etc. can facilitate transfer of microorganisms with greater ease as opposed to living at home. A Thailand study of this age group (mean age 19.2 years) found that only 56.66% of students (n = 493) have good CL wear and behaviors, despite a majority (78.57%) having good knowledge of what had been recommended to them.⁴ A U.S. observational post-market study found that more than 40% of college students wore unapproved lenses overnight.²

DAILY DISPOSABLE CLS

Transition from frequent replacement CLs to daily disposable CLs has been a trend in recent years. Not having to clean or store lenses allows for greater theoretical adherence to provider and manufacturer recommendations. Most patients who choose daily disposable CLs have cited convenience as their most important factor.^5,6

Of concern, though, is noncompliance with regard to duration of wear for single-use lenses. More than 3,800 Japanese female wearers were queried about their CL behaviors. Of the 59% who were using daily disposable lenses, only 18% were considered compliant.⁷ Reuse of lenses was the most common issue.

Similarly, in the United States, approximately 60% of daily disposable wearers report storing them in a case.⁸ Since there is no consistent guidance as to the proper storage of daily disposable CLs, this presents another challenge. For example, a large study found users storing disposable lenses in blister packages with either saline, blister package solution, or contact lens disinfection solution.⁹ Unfortunately, despite the assumed benefits that daily disposable CLs can offer, there exists a safety risk similar to that with reusable lenses when users extend the life of their daily disposable CLs.

A multi-country analysis of daily disposable CLs found 9% of participants to be noncompliant with lens replacement. Of this group, 64% wore daily lenses for only one additional day, 27% for two to six additional days, and 9% for greater than one more week.⁹

Despite their behavior, the vast majority of participants reported that adherence to a daily regimen of replacement was “extremely important” and understood eye infection to be the main risk of over-wear.⁹ The overall level of noncompliance with daily disposable lenses was 33% (805 participants, mean age = 38 years).⁹

Despite the plausible overuse of daily disposable CLs, they remain the modality that is most often complied with in terms of scheduled replacement. Daily use replacement is followed by one-month replacement in terms of compliance; two-week replacement is the schedule that the participants adhered to least.^10-13 The UCLA Contact Lens Study found the rate of compliance with replacement schedules was 86% for daily disposables, 78% for monthly replacement, and 59% for two-week replacement.¹²

PATIENT UNDERSTANDING AND CHARACTERISTICS

Some of the primary reasons CL wearers report for overusing and over-wearing lenses are to save money, to prevent running out of lenses, and having a faulty memory.^9,14 One study found that 85% of patients perceived themselves as being compliant with their lens wear and care practices, but after using a standard scoring model to determine actual compliance, 2% demonstrated “good” compliance and only 0.4% were fully compliant.¹⁵ It has been suggested that if patients are noncompliant with one aspect of CL wear, they are more likely to be noncompliant with other areas too.¹⁴

Cumulative years of CL wear have been linked to noncompliance. Eyecare professionals (ECPs) might spend more time educating new wearers and may be more conservative in their approach and recommendations.

In addition, new wearers might pay more attention to the education that they receive. This results in the veteran wearer being less compliant overall. Veteran wearers also may have had many years of asymptomatic wear and can be lulled into complacency.

Often, CL wearers do not receive negative feedback regarding their failure to adhere to provider recommendations, and they do not perceive any immediate direct threat from their noncompliance.¹⁶ Essentially, loose behavior is reinforced because nothing bad happens.

Risk-taking is an interesting characteristic of some CL wearers. Higher risk-taking personalities tend to be associated with less compliant behaviors.^14,17 Smoking has also been linked to risk-taking personalities and has been reported in CL noncompliance, especially with unapproved extended overnight wear of lenses.¹⁸

It is interesting to compare the acknowledged risks and those patients who still undertake those risks. Of queried subjects who knew sleeping in lenses was not approved, 63% still did so. Similarly, 41% over-wore their lenses despite knowing better.¹⁹ One study found that a higher risk-taking personality was a better predictor of noncompliance than age, gender, or practitioner perception.¹⁷ Risk-takers may incorrectly perceive that they are not as susceptible to problems as other wearers and may be resistant to standard care and advice, in general.¹⁷

HAND WASHING, DISINFECTION, ETC.

Exposure of CLs and cases to water has been associated with adverse events like sterile infiltrates and Acanthamoeba keratitis.^20-22 Behaviors such as CL handling with wet hands, storing and/or rinsing lenses with tap water, and swimming or showering while wearing lenses are all causes for concern.

There is a strong association between Acanthamoeba keratitis and water exposure. Microorganisms and biofilms in a water supply can promote colonization because this protozoan feeds on other microorganisms, internalizes viable organisms, and creates its own microbial reservoir in order to flourish.^23-25

The United States and the United Kingdom have had slightly different issues in terms of increased risk. The Environmental Protection Agency’s (EPA’s) changes to increase the distance between household water supply and water treatment plants in Chicago allowed for greater potential for microbes to reach patients.^26,27

Additionally, the EPA resolved to reduce the amount of carcinogenic disinfection agents in water supplies (chlorine, ozone, and chloramines), all of which act to minimize Acanthamoeba and biofilms.²⁶ These actions allowed more microbes and free-living amoebae to grow and reach patients and reportedly led to an outbreak of keratitis in 2006.²⁶

It has been found that only 1 in 3 wearers associate swimming, water sports, and tap water as risk factors for CL-related adverse events, with an even lower number understanding that showering with lenses is also a risk.¹⁵ One in 5 university-aged subjects reportedly rinsed their CLs in tap water “sometimes” and routinely showered in lenses.²

Reportedly, 86% of soft and 67% of GP CL wearers shower in lenses and 62% of soft and 51% of GP CL wearers swim in lenses.²² Overall, swimming with CLs results in a five times greater risk when compared to using goggles or disinfecting CLs immediately after finishing the activity.²⁸

A 2014 investigation of CL behaviors found that more than 60% do not practice adequate hand washing, with only a fraction of participants using soap or cleaning detergents.¹ ECPs need to be aware of hand washing instructions. When hand washing is to be performed is also in question, as it has been reported that hand washing prior to lens application happens at a far greater rate than hand washing prior to lens removal.¹⁴ This is problematic, as one study found that 100% of lenses are contaminated after removal.²⁹

Hand drying after washing is also a critical piece, as microbes dislodged from higher contamination areas near the fingertips and palms can be readily introduced to the ocular surface if not wiped from the hands with a clean towel. A study of 200 CL practitioners were queried on hand washing, and after use of UV light and a disclosing gel to objectively assess efficacy, poor techniques were identified.²⁹ Optimal washing requires use of enough soap to cover all hand surfaces and a wash duration of at least 30 seconds.^29,30

CL lens and case disinfection also remains a challenge. A high percentage of patients (29%) report that they “never” or “almost never” rubbed and rinsed their reusable CLs, even though no-rub multipurpose solutions have mostly disappeared from the market.³¹ In addition, several pathologic organisms, such as free-living Acanthamoeba and Pseudomonas, can routinely colonize on the surface of a lens and lens case.⁴ A high percentage of patients reportedly only replace their lens cases annually or, even worse, “never” replace their cases (25%).^15,31 This is dangerous, as up to 81% of cases are contaminated.^15,19

GP LENSES

GP lenses have become more popular in recent years for myopia control, orthokeratology, and scleral lens-designed fits. Compliance with GP CL wear requires ECP attention, as it does for soft CLs. A 2017 study found that 91% of GP wearers rinsed lenses with tap water and 33% stored lenses in tap water.³² Acanthamoeba is capable of adhering to GP materials and trophozoite adherence can occur in as little as 10 seconds.³² To avoid water in disinfection and cleaning, hydrogen peroxide (H₂O₂) solutions with controlled neutralization is a safer procedure, as the rinsing step is eliminated (and storage directions do not include water).²²

Given the cost differences in GP versus soft CLs, life expectancy is longer for GP lenses. There is inconsistent messaging, though, as to the duration of use that should be expected by the patient and the eyecare professional. All CLs demonstrate a deterioration in performance with age, regardless of Dk or lens material. Woods and coworkers have studied this extensively, and usage beyond 12 months is not recommended. Surface drying and scratching occurs within nine months of use, while mucus and surface deposition is seen at the 12-month point.³³

Optimally, GP lenses worn on a daily basis should be replaced every six months to avoid adverse lens and ocular integrity issues seen after as little as nine months of wear.³³

WHAT TO DO?

Improving educational outcomes for patients is a goal. Unfortunately, within minutes of a medical consultation, patients tend to forget 50% of the advice offered.^29,34

Average learning from varied techniques are 5% from a lecture, 10% from reading, 20% from demonstration, 30% from discussion, 73% from personal practice, and 90% from teaching others.²⁹ Participants who are given verbal and written instructions about case hygiene are more likely to be compliant than those who are given verbal guidance alone.³⁵

Eyecare professionals regularly provide verbal advice but do not always offer written support. It has been reported that only 3% of providers offer written advice for repeat customers.³⁶

Better and more effective patient communication can have additional desired effects. For example, 90% of compliant patients claimed to follow recommended replacement schedules because they “had complete confidence in their ECP.”¹³ Donshik and coworkers recommended steps to better engage, educate, and empower patients in an effort to improve compliance in CL wear.³⁴ They have been updated as follows:

1. Patient Education Provide simple and consistent instructions in verbal and written form at all encounters. Include details regarding wear, wearing schedule, disinfection, water exposure, and hand washing. Active and interactive education are superior to passive instruction.
2. Increase ECP Involvement ECPs should emphasize the importance of compliance and adherence to medical advice and not leave all of the dissemination to the technician.
3. Safer Care Regimens Daily disposable CLs have the greatest potential for compliance. Consensus and consistency as to what to do for a patient who removes a daily use lens midday (with the intent of eventual reapplication) needs clarification. Timely replacement is as important for GP CLs as it is for soft CLs.
4. Education of ECPs, Patients, and Legislators The entire public needs reminders that CLs are medical devices, and a lack of symptoms and complications should not lead to complacency.
5. Research Despite the lack of substantive improvements in compliance in the previous 40 years, the future has yet to be determined and requires monitoring through research.
6. ECP Compliance ECPs have occasionally been reported to offer inconsistent messaging that is not adherent to manufacturer guidelines for CLs.^9,13,31 At a minimum, ECPs need to adhere to approved replacement schedules and cleaning regimens for all CLs. CLS

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