Daily disposable contact lenses are rapidly increasing in popularity worldwide and are extremely convenient because, when worn appropriately and disposed of after each use, they do not require any supplementary care products.¹ However, not all patients can, or choose to, wear daily disposable contact lenses; therefore, contact lens care regimens are extremely important for safe reusable soft contact lens wear. To optimize success for contact lens wearers, these care regimens need to be used according to product-specific instructions. Unfortunately, patients frequently engage in noncompliant behavior when caring for their lenses, including failure to use the care regimen recommended by their eyecare practitioner (ECP), failure to rub and rinse their lenses prior to disinfection with a multipurpose solution (MPS) regimen, and failure to use fresh solution or “topping off” their solution prior to the disinfection cycle.^2-4

While patient education and proper instructions for use can help our patients be more compliant,^5,6 the reality of busy lifestyles frequently results in patients taking shortcuts in their lens care procedures.⁷ Prescribing simple care regimens may encourage better compliance from our patients. Hydrogen peroxide (H₂O₂) lens care systems meet these requirements because they generally involve fewer steps compared to MPS regimens, including no requirement to rub lenses prior to disinfection or after neutralization, therefore resulting in a more simplified process. In addition, the bubbling action in the clear case used with H₂O₂ systems allows patients to actually see an active cleaning and disinfection process, as compared with MPS solutions that do not show any change in appearance over time.⁸

The Centre for Ocular Research & Education conducted a study in 2007 that evaluated compliance with the use of several contact lens care systems that were then available.⁹ At the time that the study was conducted, instructions for the use of care regimens (in particular, MPS regimens) differed from current directions, principally with respect to the requirement to rub lenses prior to the disinfection period. Instead, most MPS care regimens at that time recommended only rinsing the lenses with the MPS solution for a period of approximately five seconds prior to placing them in the case with fresh MPS solution. The compliance rate with these care regimens was reported to be 100% for H₂O₂ users as compared with only 37% for MPS systems.⁹

Since this time, the Centers for Disease Control and Prevention (CDC) have developed a series of guidelines for the appropriate use of contact lens care systems and solutions.¹⁰ In addition, the MPS care systems currently marketed all require a rub step. In view of this, we determined that it would be interesting to re-examine the data set from 2007 to determine what the level of compliance would be for participants according to current recommendations.

ORIGINAL STUDY DESIGN

As part of the baseline evaluation of participants for the clinical trial conducted in 2007, individuals were interviewed to evaluate their habitual lens wear and care procedures. Successful wearers of reusable soft contact lenses answered a series of standardized questions about their habitual lens types, replacement frequency, and wearing time. These questions were followed by a series of questions relating to the use of their habitual lens care regimen and how they cared for their contact lens cases. The investigation was approved by a Research Ethics Committee at the University of Waterloo and was conducted following the tenets of the Declaration of Helsinki.

Descriptive statistics are presented for all of the key parameters recorded, using t tests to compare the means of two care system groups for continuous data and Fisher’s exact tests to compare the reported behaviors for categorical data. The criterion for statistical significance was p < 0.05, and two-tailed p values are reported.

DEMOGRAPHICS

Data were collected from 100 participants (87 female, 13 male). The mean age of the participants was 24.4 years ± 5.9 years (range 18 to 51 years). Thirty-seven percent were wearing two-week-replacement lenses, 62% one-month-replacement lenses, and one participant was wearing a soft lens type for which the lens material and recommended replacement frequency could not be confirmed. Fifty-four percent of the lenses worn were silicone hydrogels (SiHys), and 45% were hydrogels (Hys). Twenty-two percent of participants reported using a H₂O₂ care regimen, and 78% reported using a MPS care regimen.

Table 1 summarizes the demographics by care regimen type. Examination of these data shows that the H₂O₂ users were on average three years older compared to the MPS users, and 95% of H₂O₂ users were wearing SiHy lenses as compared with only 42% of the MPS users.

COMPLIANCE WITH LENS REPLACEMENT

Overall, 58% of participants were compliant with the recommended replacement frequency for their lens type, and 41% were noncompliant (compliance for one participant could not be determined because his/her lens type could not be confirmed). The compliance with lens replacement among H₂O₂ users was higher (73%) than among MPS users (55%); however, the difference was not statistically significant (p = 0.15). Although older participants (aged 24 years or more) were more compliant with lens replacement than younger participants were (70% versus 50%), the difference was not statistically significant (p = 0.06). No differences were found in compliance with recommended replacement frequency according to gender or degree of myopia (p = 1.00, p = 0.84, respectively).

COMPLIANCE WITH CARE REGIMEN

According to the CDC guidelines published in March 2016,¹⁰ 100% of the participants using H₂O₂ reported behaviors that would be fully compliant. This is consistent with the classification for compliance with H₂O₂ used in the original analysis of the dataset.⁹ Rubbing and rinsing soft contact lenses with the care solution after removal and prior to storage is extremely important for MPS users;^11,12 however, only 23% of MPS users reported rubbing and only 24% reported rinsing their lenses with their care solution after removal and prior to disinfection.

Further analysis showed that only 13% would have been fully compliant with current CDC guidelines to both rub and rinse their lenses before storage, as compared with 37% that were considered compliant with instructions for contact lens care from 2007 (Figure 1).

Not surprisingly, the compliance rates for H₂O₂ and MPS users are statistically significantly different (p < 0.0001). Figure 2 summarizes the proportion of MPS users who reported rubbing and/or rinsing after lens wear and prior to lens storage. Sixty-four percent of MPS users reported never rubbing their lenses, 54% reported never rinsing their lenses, and 46% reported never rubbing nor rinsing their lenses after removal and prior to storage for disinfection.

A number of factors were investigated to determine their possible association with compliance with care regimens. Age was found to possibly play a role, with only 23% of participants aged 23 years or younger being compliant, as compared with 43% of participants aged 24 years or older; however, the difference did not quite meet statistical significance (p = 0.05). It is possible that this finding was confounded by differences in the average age of the two groups, with the H₂O₂ users being significantly older than the MPS users were; however, the mean difference was only three years.

Participants who were compliant with the recommended frequency of lens replacement did not have a different rate of compliance with care regimen from those who were noncompliant with lens replacement (31% versus 34%, p = 0.83). Similarly, there were no differences in compliance with care regimen according to gender (female, 33% versus male, 23%, p = 0.54) or degree of myopia (< –5.00D, 34% versus ≥ –5.00D, 29%, p = 0.66). As noted earlier, a significantly higher proportion of H₂O₂ users were wearing SiHy lenses when compared with MPS users; however, the lens material worn is unlikely to influence the participants’ behavior with respect to compliance with care regimen use.

SOLUTION REUSE AND CONTACT LENS CASE CARE

Both H₂O₂ and MPS instructions advise to not reuse the solution or “top off.” The current CDC recommendation for MPS lens case care is to rub and rinse the contact lens storage case with fresh solution, never water, every day; excess solution should then be emptied out of the case, and the case should be dried with a fresh, clean tissue.^10,13-15 The clean case should then be stored upside down on a fresh, clean tissue with the caps off after each use.^10,16 Manufacturer instructions for H₂O₂ systems differ in that rubbing of the case is not indicated; however, instructions are given to rinse with H₂O₂. Figure 3 summarizes lens case care behaviors after contact lenses application.

In general, H₂O₂ users were more compliant with respect to contact lens case care than MPS users were, and none of the H₂O₂ users reported reuse of their solutions or use of water to rinse their cases. Overall, only four participants reported using acceptable procedures for contact lens case care (emptying used solution from the case, rinsing the case with care system solution, and leaving the case to air dry with the caps off), with three of these being users of H₂O₂ regimens.

CLINICAL IMPLICATIONS

The reasons for noncompliance with contact lens wear and care are complex and multifactorial.⁷ MPS and single-step H₂O₂ contact lens care systems have simplified contact lens care procedures, and while compliance with disinfection with H₂O₂ in this cohort of soft contact lens wearers was excellent, the level of compliance by the users of MPS care regimens was extremely poor. The majority of ECPs, both currently and also in 2007 when this study was conducted, recognize the importance of rubbing and rinsing reusable lenses after removal when using a MPS care regimen. Failure to rub and rinse lenses with a MPS solution has been shown to result in a greater load of microorganisms and to carry a greater risk for developing microbial keratitis.^12,17 Unfortunately, either this information was not being passed on to patients, was not read, or patients were not listening and following advice from their ECPs, because in this analysis, only 13% of MPS users reported following these steps every day prior to disinfection.

The contact lens wearers in this study also reported noncompliant behaviors with respect to reuse of solutions and contact lens case care. While “topping off” was not specifically reported by this cohort of participants, 3% of MPS users stated that they reused their solution for three to four days before replacing it, placing them at higher risk for developing microbial keratitis.^18-20 This compares with none of the H₂O₂ users reporting reuse of solution, possibly because of the visual cue of the bubbling action, which occurs only when fresh H₂O₂ is used in the case.⁸

Consistent with previous studies,^4,21,22 many participants reported using tap water to rinse their cases; however, this behavior was exclusive to the MPS users (37%), with none of the H₂O₂ users using tap water. Leaving the case open to air dry while the contact lenses are being worn is also recommended;¹⁶ this procedure was followed by only 36% of MPS users, as compared with 59% of H₂O₂ users. Unfortunately, poor case hygiene is common among reusable contact lens wearers, and many wearers claim that nobody has ever instructed them on how to appropriately care for their cases.⁷

None of the participants in this study reported accidental misuse of H₂O₂. Nevertheless, it should be recognized that if these products are not used as directed, transient symptoms of burning or stinging upon contact with either partially neutralized or non-neutralized H₂O₂ can occur. Reports in the literature of adverse events related to accidental exposure to H₂O₂ are rare,^23-25 and over a 10-year period, only 370 H₂O₂ lens care-related Medical Device Reports were received by the U.S. Food and Drug Administration, confirming that such incidents are extremely uncommon given the many millions of H₂O₂ uses that occurred during this period of time.²⁶ While permanent damage to the ocular tissues or vision loss from 3% H₂O₂ is extremely unlikely, it is important that patients are educated regarding the correct use of these products to minimize the risk of discomfort associated with accidental exposure.

CONCLUSIONS

This analysis has clearly shown that users of H₂O₂ care regimens are considerably more compliant with their contact lens care procedures than users of MPS care regimens are. Similar results have also been reported in a separate study involving 6,777 reusable lens wearers in which patients using a H₂O₂ care regimen were also reported to return to their ECPs for eye exams at shorter intervals and to be more compliant with their ECP’s brand recommendations.²⁷

To improve compliance, ECPs need to educate their reusable contact lens wearers on safe and efficacious methods for caring for their contact lenses, providing clear instructions both verbally and in written format. The risks associated with noncompliance should be discussed and contact lens care practices assessed carefully at follow-up visits. Prescribing a H₂O₂ care regimen is a strategy that should also be considered to improve overall compliance with reusable soft contact lens care. CLS

The authors wish to acknowledge Kathy Dumbleton for her contributions to this article. Additionally, the authors would like to acknowledge Kathy Dumbleton, Desmond Fonn, and Craig Woods for their contribution to the original 2007 study.

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