In 400 BC, Hippocrates wrote, “patients are often lying when they say they have regularly taken the prescribed medicine”. The issue that Hippocrates was highlighting was that of compliance – an important field of medicine that has long been the subject of intense medical research. The ‘blame the victim’ approach of Hippocrates is perhaps a little harsh, and we would be better served by adopting the contemporary definition of compliance offered by Sachett and Hayes,1 which is “the extent to which a patient’s behaviour coincides with the clinical prescription”.
In the contact lens field, the first peer-reviewed journal article on compliance was published in 1986 by Collins and Carney.2 They found that 74 per cent of lens wearers were non-compliant with at least one aspect of lens care. However, that study was conducted a quarter of a century ago, before the days of disposable lenses and simplified multi-purpose lens care regimens. The study of Collins and Carney2 was conducted in Australia, so to determine whether modern contact lenses and lens care systems have resulted in improved patient compliance in this region, we conducted a survey of the habits of lens wearers in Australia and a selection of other key Asian nations.
Types of Non-compliance
Compliance with the Incorrect Prescription
The vast majority of practitioners endeavour to dispense the correct and proper prescription or advice; it would be unethical to do otherwise. However, there have been well-documented cases in recent years of practitioners dispensing the incorrect prescription based on misinformation or a misinterpretation.
An example of this is practitioners advising patients to use lenses for longer than the manufacturer-recommended replacement frequency.3
Patients frequently adopt non-compliant contact lens related behaviours within 12 months of having received thorough instruction
Whether inadvertent or deliberate, incorrect prescribing is a reality that must be considered in order to fully understand the topic of non-compliance. Figure 1 is a flow diagram that reveals five possible outcomes based upon the assumption that an incorrect prescription (or incorrect advice) has been dispensed to the patient. A tick indicates the likelihood of a positive outcome, and a cross indicates the likelihood of a negative outcome.
If the patient is compliant with the incorrect prescription, a negative outcome, such as the development of a corneal ulcer, is more likely. An example of this would be a patient who complies with the erroneous instruction to re-use da
ily disposable lenses.
Now consider the case of a patient who is non-compliant with the incorrect prescription. Non-compliance can be deliberate or unintentional. A patient can be deliberately non-compliant in a rational or irrational manner. Continuing with our example – the decision to use daily disposable lenses once, instead of reusing them as erroneously advised, would constitute rational non-compliance. This should result in a positive outcome. A decision to sleep in contact lenses (a procedure that carries a greater risk of infection) instead of just wearing them during the day as advised would constitute irrational non-compliance and is likely to lead to a negative outcome.
Unintentional non-compliance can be due to forgetfulness or a misunderstanding of the instructions. It is unlikely that unintentional non-compliance will result in correct procedures being re-adopted because of the plethora of random and most likely incorrect procedures that are theoretically available.
Compliance with the Correct Prescription
A patient being non-compliant with the correct prescription probably constitutes the classical view taken by practitioners. The flow diagram in Figure 2 also reveals five possible outcomes – but this time based upon the assumption that a correct prescription (or correct advice) has been issued.
If the patient is compliant with the correct prescription, a positive outcome is more likely. Now consider the case of a patient who is non-compliant with the correct prescription. An example of a correct prescription is advice to discard of daily disposable lenses at the end of the wearing period each day. As discussed above, non-compliance can be deliberate or unintentional, and deliberate non-compliance can be rational or irrational. Rational non-compliance could be demonstrated, for example, by a decision to use a hydrogen peroxide-based disinfecting solution instead of the multi-purpose system as advised. Although most practitioners would prefer that patients do not change their lens care system without prior consultation, such a change would generally be deemed to be safe and would therefore be unlikely to result in a negative outcome.
A decision to use tap water (a procedure that carries a greater risk of infection) instead of multi-purpose disinfecting solution as advised, would constitute irrational non-compliance and is likely to lead to a negative outcome. Unintentional non-compliance due to forgetfulness or a misunderstanding of the instructions is also more likely to result in a negative outcome for reasons given previously.
Consequences of Non-compliance
There are a number of possible consequences of non-compliance in contact lens practice.4,5 In general, non-compliance will result in the following adverse effects:
- reduction of the efficacy of lens maintenance systems
- adverse reactions to lens wear such as papillary conjunctivitis and keratitis
- incorrect prescribing of lenses and/or lens care systems
- wasting of practitioner chair time
- wasting of patient time.
Clearly, satisfaction and safety with contact lens wear will be enhanced if the above adverse consequences of non-compliance can be minimised or eliminated.
Can Compliance be Improved?
Although it is possible to assess compliance via surveys and observational studies, it is not possible to rectify all identified problems. Numerous ‘non-modifiable’ risk factors that can contribute to contact lens-related problems are beyond the control of the patient and practitioner, such as the gender, socio-economic status and health-related susceptibility of the lens wearer (e.g. atopy or diabetes), the intrinsic safety of contact lenses and lens care solutions, and environmental factors (e.g. contact lens related corneal ulceration is more common in the summer).
However, modifiable risk factors can be identified and perhaps manipulated so as to produce a better outcome. The aim of this report is to identify from the literature key modifiable risk factors for the main adverse reaction to contact lens wear – contact lens-associated microbial keratitis – and to map this onto results from our survey of lens-related behaviours in the Australasian region. This information can then form the basis of advice that practitioners could be offering to lens wearers so as to improve health and safety with lens wear.
On reviewing the available literature, we have identified seven modifiable compliance-related behaviours that are associated with an increased risk of microbial keratitis. As outlined in Table 1, these behaviours fall into three categories: (a) inadequate hand washing, (b) lens wear, and (c) use of the care regimen. In relation to the analysis presented above, all of these behaviours would fall into the categories of irrational, forgetful or misunderstanding non-compliance with the presumably correct prescription.
The Australasian Compliance Survey
To evaluate compliance with contact lens use, a web-based survey of contact lens wearers was undertaken in four key Asian countries – Australia, China, India and South Korea. The survey sought to identify wearer attributes, which indicate lower compliance levels.
A total of 1,149
contact lens wearers took part in the survey, revealing information about demographics, the way in which lenses, lens cases and solutions are handled and worn, and aftercare frequency. The number of lens wearers surveyed is stratified by lens type (see Table 2).
Three general questions were asked to gauge the extent to which patients understand the importance of following the correct instructions for the maintenance of safe lens wear. A number of specific questions were put to survey participants relating to the seven modifiable risk factors identified from the literature. The questions and answers are outlined below with a brief analysis of the responses. For each of the specific questions, we have defined the behaviour that is considered to represent non-compliance.
While it is known, as discussed above, that practitioners sometimes offer advice to patients that is contrary to the manufacturers recommendations,3 it is assumed for the purposes of this survey that all participants were originally issued with the correct advice about lens wear
General Questions Relating to Patient Understanding
Risk of infection
Do you believe that in general, those wearing contact lenses can be at higher or lower risk of contracting an eye infection compared to those not wearing contact lenses?
Seventy-seven per cent of respondents believe that wearing contact lenses leads to a greater risk of contracting an eye infection compared to those who do not wear contact lenses. In particular, females and those who have received information about contact lens care believe that contact lens wearers are at a greater risk of eye infection.
Do you believe that not following the recommended lens care regime increases the risk of contracting an eye infection for a contact lens wearer?
The vast majority (94 per cent) of contact lens wearers believe that not following the recommend lens care regime increases the risk of contracting an eye infection.
Personal Experience of Eye Infections
Have you ever had an eye infection since you started wearing contact lenses?
Thirty-two per cent of respondents had suffered an eye infection since they started wearing contact lenses, with 20 per cent having suffered multiple infections. Older people tended to have more problems. Also, those who wore their lenses more frequently tended to have more eye infections than those who wore them three days a week or less.
Specific Questions Relating to Modifiable Behaviours
Inadequate hand washing
Do you wash your hands before putting lenses in? (The non-compliant behaviour: failing to wash hands before inserting lenses.)
Overall, 30 per cent of wearers were classified as non-compliant. Males, younger people and those who have not received information about contact lens care were less likely to wash their hands every time before inserting their contact lenses. Significantly higher non-compliance was observed in South Korea.
Do you wash your hands before taking out your contact lenses? (The non-compliant behaviour: failing to wash hands before removing lenses.)
Forty-one per cent of lens wearers were classified non-compliant in this regard. Males were less likely to wash their hands every time before removing their lenses as were younger contact lens wearers and those who had not received information about contact lens care. Higher non-compliance was observed in Australia and South Korea.
What do you wash your hands with: bar or liquid soap, liquid hand sanitizer, water only, wet wipes? (The non-compliant behaviour: washing hands in water only.)
Overall, 25 per cent of respondents were non-compliant with respect to the mode of hand washing. This was especially prevalent among younger lens wearers. Of those who washed their hands, the majority (48 per cent) used soap and water. All nations performed similarly in this regard.
Non-prescribed Overnight Wear
Do you ever leave your contact lenses in overnight – either intentionally or accidentally?
(The non-compliant behaviour: sleeping in lenses which have only been prescribed for daytime wear.)
Forty per cent of respondents said ‘yes – accidentally’. 35 per cent of frequent replacement lens wearers and 22 per cent of daily disposable lens wearers reported sometimes sleeping in their lenses when they should not have done so.
Lens Replacement Interval
On average, how long do you wear one pair of contact lenses before you throw them out?
(The non-compliant behaviour: failing to discard lenses in accordance with the prescribed replacement frequency.)
Overall, high levels of non-compliance were observed in all nations. For daily disposable wearers, 20 per cent admitted to wearing their lenses for more than one day ‘on average’, and thus were considered non-compliant. For two-weekly replacement modalities, on average 70 per cent wore their lenses for more than two weeks. For monthly replacement, 30 per cent were non-compliant.
On the days that you wear your daily disposable lenses, do you ever take them out, clean them and put them back in again?
(The non-compliant behaviour: temporarily removing, cleaning and then reinserting daily disposable lenses.)
Thirty-nine per cent of daily disposable wearers remove lenses temporarily for cleaning. Over a third of those who perform this procedure do so on most of the days lenses are worn. At only 17 per cent non-compliance, Australia performed best in the region. Non-compliance in this regard is especially high in South Korea.
Rub and Rinse
Do you do any of the following with your lenses once you have taken them out of your eyes? (The non-compliant behaviour: failing to rub/clean and soak/disinfect lenses following removal.)
Only 18 per cent of lens wearers adopted the correct rub/clean and soak/disinfect procedure (see Table 3).
For how many seconds do you rinse?
(The non-compliant behaviour: rinsing lenses for less than 10 seconds.) The average across the four countries was 13.2 seconds. The 59 per cent non-compliance rate in Australia was the worst in the region.
For how many seconds do you rub/clean? (The non-compliant behaviour: is to rubbing/cleaning lenses for less than 10 seconds.)
The average time spent rubbing/cleaning lenses in the region was 13.5 seconds. Again, at 42 per cent non-compliance, Australian lens wearers performed worst in the region.
Failure to use the correct solution
Which of the following have you used when cleaning and storing your contact lenses?
(The non-compliant behaviour: using water, mouth saliva or ‘other’.)
Overall, 91 per cent of lens wearers appeared to be regularly using an appropriate storage or disinfecting system. Some wearers admitted to having used either water (16 per cent) or mouth saliva (three per cent) at some point, but virtually no one used them regularly for cleaning or storing. (See Table 4)
Where do you normally store your contact lenses after taking them out? (The non-compliant behaviour: failing to use the prescribed contact lens case.)
The vast majority of lens wearers reported using a contact lens case but seven per cent admitted using a glass or mug.
Which of the following best describes your habits when storing contact lenses? (The non-compliant behaviour: failing to replace all of the solution every time.)
Only 58 per cent of lens wearers are compliant in this regard, with Australian lens wearers being the most compliant of the four nations surveyed. (See Table 5)
On average, how long do you soak/disinfect your lenses? (The non-compliant behaviour: soaking lenses for less than four hours.)
High rates of non-compliance in respect of lens soaking were observed in India and South Korea.
Do you ever clean your contact lens case?
(The non-compliant behaviour: never cleaning the lens case.)
Overall, 15 per cent of lens wearers reported never cleaning their lens case. Lens wearers in Australia and South Korea displayed the highest rates of non-compliance in respect of case cleaning.
What do you use to clean your case? (The non-compliant behaviour: using anything other than the prescribed contact lens solution to clean the lens case.)
Contact lens solution was used to clean the case by only 30 per cent of lens wearers. The majority reported rinsing their lens cases with water only.
After cleaning your contact lens case, how do you leave it? (The non-compliant behaviour: failing to leave the case dry, with the lids off, either face up or down.)
High rates of non-compliance in this regard were recorded in all nations surveyed.
Do you replace your contact lens case at semi-regular intervals or do you use one until it gets either lost or broken? (The non-compliant behaviour: failing to replace lens cases regularly – at least every three months, but preferably monthly.
Overall, 35 per cent of those who stored their lenses only replaced their lens case if it was broken or lost. This was especially the case among those wearing rigid lenses and those wearing their lenses less frequently. Similar levels of non-compliance were observed among nations.
The number of respondents reporting full compliance with all contact lens and lens care behaviours is displayed in table 6.
The clear conclusion that can be drawn from this table is that non-compliance is rife among those wearing reusable contact lenses. Of course there is less opportunity for non-compliance when using daily disposable lenses, but even when such lenses are worn, full compliance is reported by less than 20 per cent of all lens wearers in all nations. Perhaps little has changed since the 1986 report of Collins and Carney2 on contact lens non-compliance in Australia!
In this article we have identified key risk factors for contact lens-associated eye infection and have reported particular problem areas regarding modifiable behaviours that are prevalent in the Australasian region. Indeed, significant non-compliance was observed in all nations surveyed in respect of even some of the most fundamental aspects of lens wear and care.
It has been shown previously that patients frequently adopt non-compliant contact lens related behaviours within 12 months of having received thorough instruction from their eye care practitioner and/or ancillary staff.12 Nevertheless, we urge contact lens practitioners to take note of the findings of our survey and to be vigilant by way of (a) explaining to patients, at the initial dispensing visit, the correct lens wear and care procedures, and in particular (b) constantly reminding patients, at aftercare visits, of correct procedures, and correcting any non-compliant behaviours. In this way, patients will be more likely to remain happy and problem-free.
Professor Nathan Efron is a Research Professor in the School of Optometry at the Queensland University of Technology; Suzanne Efron is in private practice at EyeQ Optometrists, Mermaid Beach, Queensland; and Dr. Philip Morgan is Director of Eurolens Research at the University of Manchester, UK.
Acknowledgement: This independent research was funded by Bausch + Lomb.
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