LEARNING METHOD AND MEDIUM

This educational activity consists of a written article and
20 study questions. The participant should, in order, read the Activity Description listed at the beginning of this activity, read the material, answer all questions in the post test, and then complete the Activity Evaluation/Credit Request form. To receive credit for this activity, please follow the instructions provided below in the section titled To Obtain CE Credit. This educational activity should take a maximum of two hours to complete.

CONTENT SOURCE

This continuing education (CE) activity captures key statistics and insights from contributing faculty.

ACTIVITY DESCRIPTION

In this article, a comparison is made between the performance characteristics, and advantages and disadvantages, of daily disposable versus reusable lenses, and an analysis is presented of which lens type represents superior technology overall.

TARGET AUDIENCE

This educational activity is intended for optometrists, contact lens specialists, and other eyecare professionals.

ACCREDITATION DESIGNATION STATEMENT

This course is COPE accredited for two hours of CE credit.

COPE Course ID: 90924-CL

DISCLOSURES

Nathan Efron, AC, DSc, PhD, reports no conflicts of interest.

Philip B. Morgan, PhD, has received remuneration from CooperVision and Johnson & Johnson Vision and has a research grant or contract with Menicon, Visco Vision, CooperVision, Johnson & Johnson, Clearlab, and Daysoft.

DISCLOSURE ATTESTATION

The contributing faculty members have attested to the following:

1. That the relationships/affiliations noted will not bias or otherwise influence their involvement in this activity;

2. That practice recommendations given relevant to the companies with whom they have relationships/affiliations will be supported by the best available evidence or, absent evidence, will be consistent with generally accepted medical practice;

3. That all reasonable clinical alternatives will be discussed when making practice recommendations.

TO OBTAIN CE CREDIT

To obtain COPE CE credit for this activity, read the material in its entirety and consult referenced sources as necessary. We offer instant certificate processing for COPE credit. Please take the post test and evaluation online by using your OE tracker number and logging in to vccecredit.com.

Upon passing the test, you will immediately receive a printable PDF version of your course certificate for COPE credit. On the last day of the month, all course results will be forwarded to ARBO with your OE tracker number, and your records will be updated. You must score 70% or higher to receive credit for this activity. Please make sure that you take the online post test and evaluation on a device that
has printing capabilities.

NO-FEE CONTINUING EDUCATION

There are no fees for participating in and receiving credit for this CE activity.

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The views and opinions expressed in this educational activity are those of the faculty and do not necessarily represent the views of Contact Lens Spectrum. This activity is copyrighted to BroadcastMed LLC ©2024. All rights reserved.

CE Questions? Contact eventhelp@broadcastmed.com for help.

Release date: May 1, 2024

Expiration Date: April 1, 2027

 

PRIOR TO THE INTRODUCTION of daily disposables to the world market in the mid-1990s, all daily wear contact lenses were “reusable” and had to be maintained with care solutions and stored overnight, prior to being re-worn on multiple occasions over many weeks, months, or even years. Since their introduction, daily disposables have enjoyed wide acceptance from eyecare practitioners and lens wearers. However, despite the apparent benefits of daily disposables, there are some drawbacks that have so far limited their clinical uptake.

Here, we compare various aspects of daily disposables and reusable contact lenses, as determined from our own extensive studies as well as reports in the literature, and then weigh all considerations to arrive at a final conclusion as to which technology is superior.

HISTORICAL TIMELINE

We started conducting annual surveys of contact lens prescribing in 1996, expanding to more than 71 nations as of 2000,¹ allowing us to track global contact lens fitting over time. Figure 1 shows the percentage of soft lenses of various replacement frequencies prescribed over the course of our surveys, averaged for a group of 17 countries that have contributed long-term data (16-28 years). As can be seen from this graph, daily disposables have grown from 11% of all soft lenses prescribed in 1996 to 46% in 2023, making them the most commonly prescribed lens replacement frequency.²

The rate of prescribing reusable lenses with replacement schedules greater than one month has decreased to the same extent over the same period. Monthly replacement lens fittings have remained fairly constant over the survey period, and now represent 43% of soft lens fits. Lenses that are replaced less often than monthly are seldom fitted today. Thus, the current market can be characterized as being primarily daily disposables versus monthly reusables, with only a small number of two-weekly replacement lenses. 

It should be noted that the percentages given above represent the mean of all nations surveyed, and that there is considerable variance in the extent of daily disposable prescribing between nations. Figure 2 displays the rate of daily disposable prescribing for the past five years for the same 17 nations as reported in Figure 1. Figure 2 shows that daily disposables account for at least 60% of all soft lenses prescribed in the United Kingdom, Denmark, Australia, and Japan, and less than 20% in Bulgaria. Daily disposables account for 51% of soft lenses fitted in Canada and 41% in the U.S.

COMFORT

Soon after daily disposables entered the market in the mid-1990s, numerous authors noted the benefits of daily disposables compared with reusables in terms of comfort. For example, Solomon and colleagues³ reported that daily disposable lens wearers had fewer negative symptoms. Jones and colleagues⁴ found that lens comfort was superior, with fewer subjective symptoms (i.e., dryness, soreness, and scratchiness), in those wearing daily disposables rather than previously used reusables. In a comparison of reusables (two-weekly replacement) and daily disposables, Sindt⁵ noted that, at the very least, those wearing daily disposables benefited from greater comfort.

Contemporary studies show that daily disposables are more comfortable than various combinations of reusables and care systems.⁶ An extensive evaluation of the ocular response of neophytes fitted with one brand of daily disposables demonstrated excellent comfort.⁷ Lazon de la Jara and collleagues⁸ reported that the comfort and quality of vision associated with some contemporary daily disposables are indistinguishable from those of non-wearing emmetropes. Ichijima and colleagues⁹ demonstrated that when wearers switched to daily disposables after having worn reusables (two-weekly replacement), there was a reduction in subjective complaints of dryness.

Which technology wins? Daily disposables, because they are subjectively more comfortable.

VISION

A study by Gellatly and colleagues¹⁰ prior to the introduction of daily disposables—conducted on 51 reusable lens wearers presenting consecutively to a large clinic—observed that reduced visual acuity was associated with increased lens age (Figure 3) and increased lens spoliation in hydroxyethyl methacrylate (HEMA)lenses. Although some subjects had worn lenses for up to four years, interpolation of Figure 3 with respect to the lenses being considered in this article—i.e., those replaced monthly or more frequently, at the far left of the graph—still shows a drop of vision with increasing lens age, albeit to a very small extent.

Early studies noted subjective reports of superior vision with daily disposables versus reusables.^3,4,7 Lazon de la Jara and colleagues⁸ found that vision with daily disposables was indistinguishable from that of non-wearing emmetropes. Notwithstanding these subjective reports of vision improvement with daily disposables, there do not appear to be any randomized, controlled studies directly comparing visual acuity in those wearing daily disposables versus reusables.

Which technology wins? Daily disposables, because they may afford superior vision, at least in terms of subjective impression of vision.

OCULAR COMPLICATIONS

Corneal Infiltrative Events  The occurrence of corneal infiltrative events (CIEs) (Figure 4) is generally considered to be a key outcome variable in studies of the safety of contact lens wear. Numerous studies have confirmed a lower rate of CIEs with daily disposable lenses compared with reusable lenses. For example, Chalmers and colleagues¹¹ noted a 12.5-times lower risk of developing CIEs with daily disposables versus reusables, and Lazon de la Jara and colleagues⁶ reported a lower incidence of CIEs with a single lens brand used on a daily disposable versus a reusable basis. Chalmers and colleagues¹² reported annual rates of occurrence of CIEs of 0 to 0.4% for daily disposables versus 3% to 4% for reusables.

Which technology wins? Daily disposables, because they induce fewer CIEs.

Microbial Keratitis  Two studies have determined the incidence of microbial keratitis (Figure 5) associated with daily disposables. We reported an incidence of 4.9 and 6.4 cases of severe (microbial) keratitis per 10,000 wearers per year associated with daily disposables versus reusables, respectively.¹³ Stapleton and colleagues¹⁴ reported incidence figures of 2.0 and 1.9. In neither study^13,14 was the difference statistically significant.

We have argued that a key consideration of the clinical impact of keratitis relates to the severity of the disease, as less severe disease generally means less pain, less vision loss, quicker recovery, less intensive (and less expensive) medical care required, and less time off work.¹⁵ In this regard, it is pertinent to note that Stapleton and colleagues¹⁴ found the overall severity of microbial keratitis to be reduced with daily disposables compared to reusables. Carnt and colleagues¹⁶ recently made a similar observation with respect to Acanthamoeba keratitis.

Which technology wins? Daily disposables, because if microbial keratitis develops, which is rare, the disease is less severe in those wearing daily disposables than reusables.

Other Complications  Many noninfectious/infiltrative ocular complications associated with contact lens wear—especially corneal staining, conjunctival hyperemia, and papillary conjunctivitis—are attributable at least in part to solutions used in the care of reusables. Of course, daily disposables obviate such problems.

Solomon and colleagues³ reported that daily disposables were associated with fewer tarsal abnormalities and fewer ocular complications in general compared with reusables. Hamano and colleagues¹⁷ observed a 4.9% incidence of complications for daily disposables compared with 8.5% for reusables. We observed minimal alterations to ocular physiology among those wearing daily disposables.⁷

Ichijima and colleagues⁹ demonstrated that switching from reusables to daily disposables resulted in a significant reduction of superficial punctate keratitis. Radford and colleagues¹⁸ reported that, compared with reusables, daily disposables significantly reduced the risk of toxic/hypersensitivity and metabolic disorders.

Which technology wins? Daily disposables, as they are associated with a lower rate of ocular complications (aside from CIEs and microbial keratitis).

CONVENIENCE

Compared to those wearing daily disposables, reusable lens wearers are obliged to cope with an additional layer of complexity relating to the use of lens care solutions and lens case care. To illustrate this, we devised a comprehensive list of 53 steps required for fully compliant daily lens wear and care (Table 1).¹⁹ All 53 steps are relevant to the wearing and care of reusables; however, only the 26 steps highlighted in bold in Table 1 are required for fully compliant use of daily disposables.

It can be inferred from this analysis that daily disposable lens wearers need to contend with fewer than half the number of steps required of reusable lens wearers—or to put it another way, daily disposables are twice as convenient to use as reusables. An important caveat to this conclusion is that it assumes that all 53 steps are equally complex, which may not be the case.

Daily disposables also offer many advantages in terms of day-to-day personal logistics. Lens wearers do not need to be concerned with maintaining an ongoing supply of lens care solutions and lens cases or finding a suitable location to store these accoutrements. Daily disposables are convenient and compact for travel, there being no need to carry bulky lens care solutions. Wearers of daily disposables typically maintain a large stock of lenses, diminishing the consequences of lens loss or damage.

Which technology wins? Daily disposables, as they are more convenient to use.

COMPLIANCE

Compliance with recommended practices and procedures involved in contact lens wear falls into two broad categories: lens handling and maintenance (hand hygiene, lens application and removal, lens cleaning and disinfection, and lens case care); and lens replacement and use (replacing lenses according to specified lens life and removing lenses before sleep).

Lens Handling and Maintenance  The fact that there are twice as many steps involved in wearing reusable lenses compared with daily disposables means that there is a greater potential for noncompliance with reusables. This was confirmed in our evaluation of compliance with lens handling and maintenance in 14 countries, using a web-based survey of 4,021 contact lens wearers.²⁰

Full compliance was found to be rare for most lens users, although better for those using daily disposables. Behaviors associated with the lowest levels of compliance included rubbing and rinsing, handwashing, and case cleaning. The question of noncompliance with lens care procedures is, of course, moot for daily disposables.

Which technology wins? Daily disposables, as they are associated with better compliance in terms of lens handling and maintenance.

Lens Replacement and Use  Dumbleton and colleagues²¹ reported that 12% of lens wearers given correct instructions reused their daily disposables. Reuse of lenses poses a significant risk for those using daily disposables, as they are unlikely to have received proper training in cleaning and disinfection of lenses and may not use a lens case or disinfecting solutions.²² In particular, new wearers of daily disposables who have not previously worn other lens types—and have thus never been instructed in lens care—may adopt unwise practices through ignorance (e.g., storing a lens overnight in tap water).

Those prescribed contact lenses for daily wear only may occasionally be noncompliant by deliberately or unintentionally sleeping in lenses. This aspect of noncompliant lens use is problematic, as overnight lens wear is associated with a greater risk of ocular complications such as microbial keratitis.^13,14

Which technology wins? There is no winner here; users of both daily disposables and reusables can be noncompliant in lens replacement and use.

COST

The distribution of the number of times daily disposables and reusables are worn per week is shown in Figure 6, which is derived from our contact lens prescribing database. The distribution for daily disposables is trimodal, with the largest peak for full-time wear. The distribution for reusables shows a pronounced bias toward full-time wear. This analysis is useful considering the cost implications of lens wear, which are heavily influenced by the wearing habits of individuals, as explained below.

We have previously constructed a “cost-per-wear” model to assist practitioners and lens wearers in considering the cost implications of various lens replacement frequencies, tailored to the wearing habits of individuals.²³ The cost-per-wear is a simple calculation of the total cost of lenses (plus solutions for those wearing reusable lenses and professional fees) over a 12-month period divided by an estimate of the number of days that lenses will be worn over 12 months. This cost-per-wear model, as applied to popular spherical lens designs from a single manufacturer, is displayed in Figure 7 for daily disposables and reusables (monthly replacement) in relation to the number of days per week of lens wear.

Full-Time Wear  As is evident from Figure 7, reusables are less expensive than daily disposables for those wearing contact lenses on a full-time basis (five to seven days per week).

It should be noted that this model assumes that lens wearers are fully compliant with respect to solution usage (for reusable lens wearers) and lens replacement. For example, it is assumed that a person wearing monthly replacement lenses one day per week would still discard lenses every month. This scenario would represent a highly inefficacious approach to lens wear and highlights the importance of prescribing lenses of appropriate replacement frequency in relation to the anticipated pattern of lens wear, in order to minimize costs to the wearer.

For full-time wearers, the obvious corollary of reusables being less expensive is that daily disposables are more expensive. However, we would suggest that many full-time lens wearers would be prepared to pay extra for the enhanced comfort, vision, ocular health, and convenience afforded by daily disposables.

Which technology wins? Reusables, as they are less expensive for full-time lens wear.

Part-Time Wear  For part-time wear, defined as wearing lenses one to four days per week, daily disposables are less expensive than reusables. Our cost-per-wear model is robust, in that similar cost differentials also apply for toric and multifocal lenses and across nations.^23,24 Although these models were constructed over a decade ago, sample calculations confirm that the general construct of Figure 7 would be very similar today, allowing for inflation.

Which technology wins? Daily disposables, as they are less expensive for part-time lens wear.

ENVIRONMENTAL IMPACT

Several studies have measured the annual waste created by the use of daily disposables versus reusables.^25,26Specifically, the mass of waste plastic and paper was determined (solutions were ignored because they have a negligible environmental impact). It was established that full-time use of daily disposables generates 1.06 kg of waste annually compared to 0.83 kg generated by reusables (monthly replacement).²⁶ Plastic was the dominant material in both modalities.

With daily disposables, 64% of waste by mass comprises plastic blister trays. For reusables, where figures from lens and multipurpose solution packaging are combined, plastics accounted for 67% of waste by mass. Multipurpose solution bottles alone made up almost half the waste (45%) associated with reusables.

Those wearing reusables can recycle 78% of waste at home, whereas those wearing daily disposables have access to recycling options that allow them to recycle 100% of lens-related waste.²⁶ Worn contact lenses should never be disposed of down the sink or lavatory. Practitioners should ensure that lens wearers are aware of responsible end-of-life recycling and disposal options for all contact lens waste.

Full-Time Wear  Full-time lens wear was calculated to represent just 0.20% to 0.26% of the 412 kg of household waste generated per person, per year in the United Kingdom.²⁶ Figure 8 shows that the overall mass of waste associated with daily disposables has diminished over the nearly two decades between our two analyses^25,26 due to more efficient lens packaging. This graph also demonstrates that waste is greater with daily disposables compared with reusables when used on a full-time (or near-full time) basis; indeed, when worn seven days per week, daily disposables generate 27% more waste than reusables.²⁶

Which technology wins? Reusables, because for full-time or near-full time wear they generate less waste than daily disposables.

Part-Time Wear  It is also evident from Figure 8 that for part-time wear, daily disposables generate less waste compared to reusables. Accordingly, a part-time lens wearer who is particularly environmentally aware may opt for daily disposables.

Which technology wins? Daily disposables, as for part-time wear they generate less waste than reusables.

LENS MATERIALS AND DESIGNS

When daily disposables entered the market in the mid-1990s, they were only available in spherical form, and this remained the case for some years. However, with the increasing popularity of daily disposables and ongoing improvements in manufacturing processes, daily disposables have become available in a growing variety of materials and designs.

At the present time in the U.S., 35 daily disposable lens types/materials are available; specifically, 16 spherical, eight toric, seven multifocal, two myopia control, and two cosmetic tinted.²⁷ Nevertheless, there are certainly more reusable lens types/designs available today, and power ranges are generally more expansive for reusables.

Which technology wins? Reusables, as a result of the broader availability of lens types, designs, and power ranges.

PRACTICE MANAGEMENT

Specific advantages of daily disposables from the standpoint of practice management include the following:

• Less education time is required (less advice has to be given about lens care).

• Less professional “chair time” is required, as there are no problems relating to lens care solutions (e.g., toxicity or sensitivity reactions)²⁸ and fewer ocular complications of lens wear compared with those experienced with reusables.²⁹

• Less ancillary staff time is required because there is no need for discussions and sales transactions relating to lens care products.

• The regular supply of large numbers of lenses required for daily lens disposal can be leveraged from a practice management standpoint by introducing strategies such as monthly payment plans³⁰ and subscriber membership systems,⁹ which are attractive business models and practice builders.³⁰

Which technology wins? Daily disposables, as they offer many advantages in terms of practice management.

CONCLUSION

The most obvious advantage offered by daily disposables is wearing a fresh, sterile pair of lenses each day. However, when taking all considerations into account, as summarized in Table 2, it can be observed that this is not a “one-horse race.” There are circumstances in which reusables might be preferred, for example, in the case of a highly astigmatic, cost-conscious, full-time lens wearer. This analysis highlights the importance of personalized prescribing—considering a range of factors on a per-person basis—when deciding whether daily disposables or reusables are best for a given wearer.

Which technology wins overall? Daily disposables, as in Table 2 (available online) they have 10 ticks and reusables have only three ticks. Daily disposables are therefore likely to be the lens of first choice for most wearers.

References

1. Morgan PB, Efron N. Global contact lens prescribing 2000-2020. Clin Exp Optom. 2022 Apr;105):298-312.

2. Morgan PB, Woods CA, Tranoudis IG, et al. International contact lens prescribing in 2023.Contact Lens Spectrum. 2024 Jan;39:20-28.

3. Solomon OD, Freeman MI, Boshnick EL, Cannon WM, et al. A 3-year prospective study of the clinical performance of daily disposable contact lenses compared with frequent replacement and conventional daily wear contact lenses. CLAO J. 1996 Oct;22:250-257.

4. Jones L, Jones D, Langley C, et al. Subjective responses of 100 consecutive patients to daily disposables. Optician. 1996;211(5536):28-32.

5. Sindt C. Daily disposable versus two-week disposable lenses. Contact Lens Spectrum. 2000 May;14:33-38.

6. Lazon de la Jara P, Papas E, Diec J, Naduvilath T, Willcox MD, Holden BA. Effect of lens care systems on the clinical performance of a contact lens. Optom Vis Sci. 2013 Apr;90:344-350.

7. Morgan PB, Chamberlain P, Moody K, Maldonado-Codina C. Ocular physiology and comfort in neophyte subjects fitted with daily disposable silicone hydrogel contact lenses. Cont Lens Anterior Eye. 2013 Jun;36:118-125.

8. Lazon de la Jara P, Diec J, Naduvilath T, Papas EB. Measuring daily disposable contact lenses against nonwearer benchmarks. Optom Vis Sci. 2018 Dec;95:1088-1095.

9. Ichijima H, Karino S, Sakata H, Cavanagh HD. Improvement of subjective symptoms and eye complications when changing from 2-week frequent replacement to daily disposable contact lenses in a subscriber membership system. Eye Contact Lens. 2016 May;42:190-195.

10. Gellatly KW, Brennan NA, Efron N. Visual decrement with deposit accumulation of HEMA contact lenses. Am J Optom Physiol Opt. 1988 Dec;65:937-941.

11. Chalmers RL, Keay L, McNally J, Kern J. Multicenter case-control study of the role of lens materials and care products on the development of corneal infiltrates. Optom Vis Sci. 2012 Mar;89:316-325.

12. Chalmers RL, Hickson-Curran SB, Keay L, Gleason WJ, Albright R. Rates of adverse events with hydrogel and silicone hydrogel daily disposable lenses in a large postmarket surveillance registry: the TEMPO Registry. Invest Ophthalmol Vis Sci. 2015 Jan 8;56:654-663.

13. Morgan PB, Efron N, Hill EA, Raynor MK, Whiting MA, Tullo AB. Incidence of keratitis of varying severity among contact lens wearers. Br J Ophthalmol. 2005 Apr;89:430-436.

14. Stapleton F, Keay L, Edwards K, et al. The incidence of contact lens-related microbial keratitis in Australia. Ophthalmology. 2008 Oct;115:1655-1662.

15. Efron N, Morgan PB. Rethinking contact lens associated keratitis. Clin Exp Optom. 2006 Sep;89:280-298.

16. Carnt N, Minassian DC, Dart JKG. Acanthamoeba keratitis risk factors for daily wear contact lens users: a case-control study. Ophthalmology. 2023 Jan;130:48-55.

17. Hamano H, Watanabe K, Hamano T, Mitsunaga S, Kotani S, Okada A. A study of the complications induced by conventional and disposable contact lenses. CLAO J. 1994 Apr;20:103-108.

18. Radford CF, Minassian D, Dart JK, Stapleton F, Verma S. Risk factors for nonulcerative contact lens complications in an ophthalmic accident and emergency department: a case-control study. Ophthalmology. 2009 Mar;116:385-392.

19. Efron N, Morgan PB. Rethinking contact lens aftercare. Clin Exp Optom. 2017 Sep;100:411-431.

20. Morgan PB, Efron N, Toshida H, Nichols JJ. An international analysis of contact lens compliance. Cont Lens Anterior Eye. 2011 Oct;34:223-228.

21. Dumbleton K, Richter D, Woods C, Jones L, Fonn D. Compliance with contact lens replacement in Canada and the United States. Optom Vis Sci. 2010 Feb;87:131-139.

22. Boost M, Poon KC, Cho P. Contamination risk of reusing daily disposable contact lenses. Optom Vis Sci. 2011 Dec;88:1409-1413.

23. Efron N, Efron SE, Morgan PB, Morgan SL. A ‘cost-per-wear’ model based on contact lens replacement frequency. Clin Exp Optom. 2010 Jul;93:253-260.

24. Efron SE, Efron N, Morgan PB, Morgan SL. A theoretical model for comparing UK costs of contact lens replacement modalities. Cont Lens Anterior Eye. 2012 Feb;35:28-34.

25. Morgan SL, Morgan PB, Efron N. Environmental impact of three replacement modalities of soft contact lens wear. Cont Lens Anterior Eye. 2003 Mar;26:43-46.

26. Smith SL, Orsborn GN, Sulley A, Chatterjee NB, Morgan PB. An investigation into disposal and recycling options for daily disposable and monthly replacement soft contact lens modalities. Cont Lens Anterior Eye. 2022 Apr;45:101435.

27. Gulmiri A, Liao J. 2023 contact lenses and solutions summary. Contact Lens Spectrum. 2023 Sept (Suppl):6-27.

28. Richdale K, Lam DY, Wagner H, et al. Case-control pilot study of soft contact lens wearers with corneal infiltrative events and healthy controls. Invest Ophthalmol Vis Sci. 2016 Jan 1;57:47-55.

29. Hickson-Curran S, Spyridon M, Hunt C, Young G. The use of daily disposable lenses in problematic reusable contact lens wearers. Cont Lens Anterior Eye. 2014 Aug;37:285-291.

30. Patel NI, Naroo SA, Eperjesi F, Rumney NJ. Customer loyalty among daily disposable contact lens wearers. Cont Lens Anterior Eye. 2015 Feb;38:15-20.