WEARER COMPLIANCE

How Compliant are Today's Lens Wearers?

This study evaluated compliance with lens replacement and care for daily disposables and silicone hydrogels.

By Kathryn Dumbleton, MSc, MCOptom, FAAO, FBCLA; Craig Woods, PhD, MCOptom, FAAO; Lyndon Jones, PhD, FCOptom, FAAO; & Desmond Fonn, MOptom, FAAO

Clinicians have recognized contact lens wearer compliance as a topic of concern for some time, with the first peer reviewed article investigating contact lens compliance appearing almost 25 years ago (Collins and Carney, 1986). Patients can be considered "noncompliant" with contact lens use in many different ways. A "Quick Vote" question posted on the Silicone Hydrogels Web site (www.siliconehydrogels.org) (Anon, 2009) asked eyecare practitioners (ECPs) in which area of contact lens care and maintenance did they consider their patients to be the most noncompliant. The most frequent responses were "failure to replace lenses when scheduled" (55 percent), followed by "failure to wash hands prior to handling lenses" (18 percent), "switching care products" (13 percent), and inappropriate use of care products (9 percent).

Several studies have shown that patients are not always compliant with replacement schedules, but these were conducted when daily disposable (DD) and frequent replacement silicone hydrogel (SiHy) lenses were not in widespread use (Smith, 1996; Coopersmith and Weinstock, 1997; Jones et al, 2002). The Centre for Contact Lens Research (CCLR) at the University of Waterloo has recently conducted a new study principally to investigate compliance with replacement of these lens types, but also to investigate contact lens care procedures (Dumbleton et al, 2009). The aims of the study were: to assess current recommendations for replacement frequency (RF) of SiHy and DD lenses, to determine compliance (or noncompliance) with the manufacturer- recommended replacement frequency (MRRF), to evaluate contact lens care, and to investigate the reasons for noncompliance.

Study Design

To recruit the ECPs, e-mails were sent on behalf of the CCLR by "Review of Optometry Online" and Ciba Vision Corporation to ECPs in clinical practice in the United States. ECPs agreeing to participate in the study completed an online registration form for the CCLR and were then mailed a study package. This package included instructions for the ECPs to invite the next 20 patients wearing DD lenses or SiHy lenses (those intended to be replaced every two or four weeks) who attended their practice to complete a survey evaluating their contact lens wear and care procedures. If a patient declined, the next eligible patient was then asked. The surveys were confidentially completed by the patients and then sealed in an envelope provided to them, on which the ECP was required to record the contact lens type, their recommendation for RF, and the lens powers. The ECP then returned all of the completed surveys (in their sealed envelopes) to the CCLR. Both the ECPs and the patients taking part in the study retained anonymity from the CCLR. Ethics approval was obtained through the Office of Research Ethics at the University of Waterloo prior to commencement of the study and was conducted following the tenets of the Declaration of Helsinki.

Survey Data on Lens Replacement

A total of 309 ECPs from 44 states completed the registration form and were sent study packages, of which 158 ECPs returned patient surveys. Eighty-nine percent of the ECPs worked in independent practice, and 11 percent were associated with a corporate entity. The ECPs returned 1,859 patient surveys of which 1,654 patient respondents were eligible for analysis, the remaining surveys being either incomplete or completed by patients wearing ineligible lens types.

Demographics and Lens Types Sixty-six percent of the surveys analyzed were completed by female patients. The mean age of all patients was 34 years ± 12 years (ranging from 14 to 79 years), with a median patient age of 32 years. The patients surveyed were experienced contact lens wearers (median of 11 years of wear). The daily wear patients wore their lenses for an average of six days per week with a mean wearing time of 13 hours each day. Twelve percent of patients reported wearing lenses on an extended wear basis, and 47 percent of patients reported end-of-day discomfort for the final 3 ± 2.1 hours of lens wear each day.

Sixteen percent of the contact lenses worn were DD, 45 percent were two-week replacement SiHy lenses and 39 percent were one-month replacement SiHy lenses (Dumbleton and Jones, 2009). In 6 percent of cases, the lens type as reported by the patients did not match that recorded by the ECP, and 20 percent of patients were unsure of the contact lens type that they were wearing.

ECP Compliance With Recommended Replacement Frequency There was a higher percentage of ECPs who recommended RFs that were longer than the MRRF for two-week replacement SiHy lenses (18 percent) compared to those for DD lenses (4 percent) and one-month replacement SiHy lenses (1 percent). Figure 1 shows the numbers of compliant and noncompliant recommendations for each contact lens type. In some cases a shorter RF was recommended when compared with the MRRF; this occurred for only 1 percent of two-week replacement SiHy lens wearers but for 18 percent of one-month replacement SiHy lens wearers. The reasons for the shorter times were not specifically investigated, but could be related to individual patient requirements or to the ECP misunderstanding the MRRF for some lens types.

Figure 1. The number of patients for whom the ECP recommendation complied or did not comply with the MRRF.

When the patients were asked what RF had been recommended by their ECP (recorded on the survey), the noncompliance rates were higher for all lens types, with the greatest rate reported for twoweek replacement SiHy lenses (22 percent) followed by DD lenses (10 percent) and one-month replacement SiHy lenses (2 percent). Four percent of patients reported that their practitioner gave no RF recommendation.

Patient Compliance With Recommended Replacement Frequency In general, patients recognized the importance of replacing their lenses on schedule, with 94 percent of DD wearers, 71 percent of two-week replacement SiHy wearers, and 80 percent of one-month replacement SiHy wearers rating this to be either "extremely important" or "important." What patients do and what they are told to do may, however, be quite different.

This was the case in the current study, and the actual RF exceeded the MRRF for 40 percent of the patients completing the survey. Because the ECPs were not always compliant with the MRRF, it may be inappropriate to include those patients whose ECPs recommended wearing periods that were longer than the MRRF (as stated by the ECPs on the envelopes) in the noncompliant group, as essentially the patients were being "compliant" with "noncompliant" advice. When these cases were excluded from the analysis, the overall noncompliance rates for patient replacement was 38 percent, and there was significant variation in the noncompliance rates among lens types worn. The lowest noncompliance rate occurred in DD wearers (12 percent), followed by onemonth replacement SiHy wearers (28 percent), with the highest rate occurring in two-week replacement SiHy wearers (52 percent). Figure 2 shows the numbers of compliant and noncompliant patients for each lens type.

Figure 2. The patient reported compliance with the MRRF and/or the ECP recommendation for RF.

Reasons for Noncompliance With Lens Replacement The reasons given for not replacing lenses on schedule varied according to the lens type worn. For two-week replacement SiHy and one-month replacement SiHy wearers, the most frequently reported reason (53 percent) was that they simply forget on which day to replace their lenses. When DD wearers failed to replace lenses as recommended (i.e. noncompliant wearers), the most frequently reported reason given was "to save money" (29 percent of these wearers); 23 percent said that they forgot which day to replace them, which seems curious because these lenses should be replaced every day; 26 percent cited "lack of time," which could possibly be interpreted as not getting around to reordering replacement lenses, but this cannot be confirmed from the study data.

Overall, 53 percent of patients thought that a reminder system would help them to comply with the recommended replacement schedule. Of the suggested reminder systems, 29 percent preferred a cell phone or text message system, 26 percent preferred the option of a particular replacement day each week or month, 22 percent preferred a countdown display on their contact lens case, 19 percent preferred an email reminder, and 14 percent preferred using an "old-fashioned" paper calendar.

Survey Data on Contact Lens Care Procedures

Forty-eight percent of the patients wearing SiHy contact lenses reported using a brand name multipurpose solution, 9 percent reported using a hydrogen peroxide care regimen, and 40 percent could not recall or did not know the name of their current care regimen. Only 3 percent reported using a generic care regimen, but it is quite likely that a large proportion of those who did not record a name for their care regimen were also using a generic brand. Twenty-seven percent of patients reported having switched their care system recently, with 52 percent of these patients reporting that this was as a result of their ECP making a recommendation to change the regimen; for 19 percent the reason given was cost, and for 12 percent it was convenience. When questioned about contact lens case replacement, 50 percent of patients using a case reported that they replaced it at least every three months; for 20 percent of patients the response was every six months, 16 percent responded that they replaced their lens case every year, and 14 percent responded that they never replaced their lens case.

Results by Patient Compliance Group A number of differences have been reported between compliant and noncompliant patients in other studies on compliance with contact lens wear and care (Chun and Weissman, 1987; Sokol et al, 1990; Claydon and Efron, 1994; Yung et al, 2007). In the current study, noncompliant patients were slightly younger compared to compliant patients (33 versus 35 years old) with no difference in their gender distribution. A higher proportion of patients who were noncompliant with RF wore toric lenses (20 percent versus 13 percent of compliant patients); a likely explanation for this finding is the higher cost of toric contact lenses, which may encourage some patients to extend the replacement interval for their lenses to save money.

Interestingly, a higher proportion of patients who were noncompliant with RF did not have an up-todate spectacle prescription (14 percent versus 8 percent of compliant patients), possibly supporting the belief that some patients are simply prone to be less compliant to general recommendations relating to their eye care. End-of-day discomfort was reported by a higher proportion of patients who were noncompliant with RF (51 percent) when compared with those who were compliant with RF (45 percent), suggesting that replacing lenses on schedule may also play a role in lens comfort reported by patients (Dumbleton et al, 2010).

Summary

Compliance with RF remains an issue with today's contact lenses. While ECPs generally recommend RFs consistent with the MRRF for DD and onemonth SiHy lenses, they often recommend longer intervals for two-week SiHy lenses. Patients in this study were most compliant when wearing DD lenses and least compliant when wearing two-week SiHy lenses. More than half of those not replacing lenses when recommended reported that this was because they simply forgot on which day to replace their lenses. For these patients, it is possible that instigating a reminder system may aid compliance with RF.

A high proportion of patients could not recall which care regimen they were using, and contact lens cases were replaced at least every three months by only half of the patients. Both of these findings support the ongoing need for ECPs to carefully counsel their patients with respect to contact lens care procedures. CLS

This study was funded by Ciba Vision.
For references, please visit www.clspectrum.com/references. asp and click on document #175.