Daily Disposable Contact Lenses: The Good, the Bad and the Reasons Why

By Evra Taylor

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There is no doubt that we live in a disposable society. In contrast to earlier times when excellent craftsmanship meant product durability, nowadays our first response when something has served its purpose is to get rid of it. This is true for a diverse range of products from personal razors to computers, whose built-in obsolescence boosts manufacturers’ profits.

While some people would describe the phenomenon of “disposability versus longevity” as negative, in some instances, modern technology has led to manufacturing breakthroughs that translate into greater consumer convenience. Daily disposable contact lenses are one example of this.

Overview

In 1994, Johnson & Johnson introduced ACUVUE® – the first daily disposable contact lenses in the U.S. Contact lens technology has progressed significantly since then. Now, even toric lenses for the correction of astigmatism as well as bifocals are available in daily disposable format.

Daily disposable contact lenses are ideal for occasional use such as playing sports or for special events involving one-time use – like a wedding – where replacing eyeglasses with contact lenses is an important cosmetic consideration. These lenses are also a good choice for people who combine contact lens wear with spectacle use. Some of today’s disposable lenses are made of the same materials as traditional lenses; other disposables are made from new materials developed specially for this purpose.

An important advance in the technology of these lenses is that they are now offered in a broader sphere power range than ever before, from +8.00D to -12.00D. In addition, some lenses offer diameters surpassing 14 mm, which makes them available to a greater number of patients.

Advantages

Daily disposable contact lenses provide several advantages, the chief of which is convenience. Since contact care, cleaning and disinfection are not required with daily disposables they provide a measure of ease of wear.

Daily disposables also offer a number of key “ingredients” that practitioners look for in a high-performance lens, including low rotation (which is of value with toric lenses), lens stability and high oxygen transmissibility.

Daily disposables are thought to reduce the risk of protein deposits, eye infections caused by the lenses or the solutions used to clean them – including fungal keratitis and Acanthamoeba keratitis – and eye ulcers. Since they are replaced daily, the time for deposits like proteins and allergens to build up on the lenses is reduced. Moreover, many of these lenses offer some protection from UV rays, which is particularly relevant for patients who play sports. However, it should be noted that the UV protection does not protect the bulbar conjunctiva which means that daily disposables do not eliminate the need for the eye protection afforded by proper sunglasses.

Although toss-away lenses are perceived as expensive, they eliminate the need for contact lens solution and, more importantly, the contact lens case, which is a significant risk if not disposed of at least once every two to three months.

Some practitioners maintain that the difference in the cost of disposable contacts compared to that of traditional contact lenses is minimal and is offset, at least in part, by the reduced need for cleaning products.

Disadvantages 

Daily disposable lenses might not be available for certain uncommon prescriptions, and certain specialty soft contact lenses, such as color contacts and theatrical contact lenses, are not available in daily disposable form.

Complications due to contact lens wear are estimated at five percent of contact lens wearers each year.Most of these situations arise from non-compliance with the prescribed wear schedule, not using solutions properly, improper maintenance of lens cases or failing to dispose of cases at least every three months. It is crucial that eyecare practitioners discuss the importance of compliance when counselling patients on contact lens wear.

Daily disposable contact lenses represent a positive advance in terms of patient convenience and comfort and may, in fact, constitute a large portion of your practice. However, they are not without drawbacks and patients should be presented with “the whole truth and nothing but the truth” when it comes to their use.

Changing Demographics and Evolving Contact Lens Technology

By Evra Taylor

makingcontactDemographically speaking, we are living in an unprecedented time in history. Never before has North America been home to so many baby boomers, individuals aged between 48 and 66. The effects of the aging population on our overall health, and on ocular health in particular, must be viewed in terms of vision correction.

According to Statistics Canada,Canada’s boomer population will increase dramatically over the next three decades. By 2020, those aged 65 and older will comprise 18 per cent of the population. Most startling is the fact that between 2005 and 2036, seniors’ representation in the population is expected to almost double, to a staggering 24.5 per cent.

Meeting the Eyecare Needs of an Aging Demographic 

The “greying of Canada” means that golden-agers will make up a significant and growing portion of optometric practices, a fact that has implications for contact lens use in particular. Today’s baby boomers are active and vibrant, and enjoy participating in a variety of sports, as well as cultural and work-related activities. Happily, this coincides with practitioners’ growing armamentarium of contact lenses designed to suit all of these needs.

Given the preponderance of individuals over 40, presbyopia – which affects near and intermediate (arm’s-length) vision – is a growing concern. By the age of 50, multifocal lenses may enable a person to see clearly across a room and up close, but vision at arm’s length may be moderately  blurred. In the past, multifocal lenses provided less-than-satisfactory results, often producing glare and discomfort. While some optometrists turned to monovision as an alternative, this resulted in compromised quality of vision and depth perception.

The good news is that contact lens designs and materials have since evolved to better meet consumers’ changing needs. Recent developments in contact lenses now permit better visual quality at all distances for many individuals and minimally compromised vision for the rest. Numerous multifocal lens designs are available to patients, depending on their age and visual requirements. Multifocal lenses for specific activities like computer work, as well as various sports, are examples of the specificity of the current contact lens market.

With the advent of multifocal contact lenses, baby boomers can enjoy the convenience and aesthetic advantages of contact lenses as a replacement for eyeglasses. Soft, disposable multifocal designs, for example, have simplified the fitting process, while providing better visual quality than earlier renditions. Each multifocal lens design has a different lens geometry, with unique positive and negative features that must be taken into account. Manufacturers’ fitting guides for each design provide helpful guidance in understanding these features and the ways in which various designs differ from one another.

Aspheric multifocal contact lens designs, in which both distance and near prescriptions are placed centrally, mimic the effect of progressive eyeglass lenses. The various prescriptive powers are blended across the lens in a smooth transition. While some practitioners find that fitting multifocal lenses is time-consuming, the benefits of having a satisfied patient return make the effort worthwhile. It is also true that more complex lenses require more time on the part of the practitioner and that fees will reflect this.

Dry Eye and Aging

The discomfort caused by dryness is one of the common symptoms that causes contact lens dropout across virtually all age groups. Dryness is caused by a multitude of factors, not all of which are purely ocular. According to the National Eye Institute’s Visual Function Questionnaire: Impact of Dry Eye on Everyday Life (IDEEL), approximately 34 per cent of contact lens wearers discontinue use at least once, primarily because of dry eye symptoms.

In light of this, eyecare practitioners should be mindful of patient groups that are particularly susceptible to dry eye and adjust their contact lens materials and design accordingly. Further, careful selection of disinfection care systems is also required for those individuals. This includes post-menopausal women suffering symptoms of dryness with contact lens wear, women who experience hormonal changes associated with menopause, as well as those who take estrogen supplements without progestin. Other major contributing factors that need to be considered in contact lens and lens care product prescribing are LASIK surgery, which has become increasingly popular among baby boomers, and diabetes, which has reached epic proportions.

Patient Communication

Communicating with patients in order to fully understand their lifestyle and vision needs, particularly in terms of near and intermediate distances (including the patient’s priorities for distance vision), will help determine visual needs and contact lens choice. It’s one thing to have advanced contact lens technology at one’s disposal; communicating its availability is another. While optometrists are fortunate to be able to carry a more expansive contact lens inventory than ever before, explaining the therapeutic pros and cons of each design is essential and will build the patient’s confidence in the practitioner as he/she leads the patient into the most ideal modality of vision correction.

Special Contact Lenses Can Help Avoid Car Accidents

Special Contact Lenses Can Help Avoid Car Accidents
By Paddy Kamen

Driving more slowly at night seems to make sense from a safety standpoint. But when you’re driving slowly because you can’t see properly then all bets are off.

A study published in Investigative Ophthalmology & Visual Science

[i](the official publication of the Association for Research in Vision and Ophthalmology) found that multifocal contact lens wearers, while driving slower, also had a reduced ability to recognize road hazards.

For the study, 11 adults aged 45-64 drove on a closed circuit driving track at night. Their performance was judged on five criteria: road sign recognition, hazard recognition and avoidance, the ability to stay in the correct lane, near target recognition, and the distance required to recognize standard street signs. Participants’ only experience with vision correction prior to the experiment was using reading glasses for near vision.

The study also found that multifocal contact lens wearers had to be much closer to road signs to detect them than did those wearing eyeglasses. Poor vision has serious implications for road safety because not reading signs from a safe distance may result in sudden, dangerous lane changes.

The fact that low light conditions appear to significantly alter safety in night driving for multifocal contact lens wearers and others on the road is a concern that hasn’t previously been recognized or addressed. The study’s lead author, Byoung Sun Chu, Ph.D, formerly of theSchoolofOptometry, Queensland University of Technology inBrisbane,Australia, points out that eyecare practitioners may need to rethink vision correction for those who drive long distances at night.

« One alternative is to prescribe multifocal contact lenses for daytime use and a different correction for driving at night, » notesChu.

Bausch + Lomb appears to be the only contact lens manufacturer that has responded to the needs of contact lens wearers who travel, live and work in low light conditions. Their PureVision® 2 HD contact lense is the latest lens specifically designed for crisp, clear everyday vision even in low light conditions. The unique lens design is optimized to help correct spherical aberration (an optical effect causing blurred vision, halos and glare) across the entire lens power range.

The number of people who would benefit from these lenses is not insignificant. StatisticsCanadanotes that Canadians drive approximately 15 million km each day between the hours ofmidnightand6 a.m., when visibility is lowest. And there are 640,000 truck drivers on the road every day, many of whom drive through the night. Glare and halos, which impede vision, limit a driver’s ability to visually detect road conditions or obstructions.

Another situation that may warrant the use of PureVision 2 HD contact lenses for effective vision is shift work. Nearly 30 per cent of all Canadians work shifts and almost 55 per cent of nurses work evening and night shifts where lighting conditions may be less than optimal for effective vision. Even ostensibly pleasurable activities like attending the movies can be negatively affected by glare and halos when individuals are wearing vision correction that doesn’t serve them well in low light conditions.

Bausch + Lomb commissioned a study on the effect of glare and halos, which was conducted by an independent market research firm, Market Probe: Europe. The study, titled Needs, Symptoms, Incidence, Global Eye Health Trends (NSIGHT), surveyed 3,800 spectacle and contact lens-corrected subjects, 15 to 65 years of age, from seven countries (China, Korea, Japan, France, Italy, United Kingdom and the U.S.) to better understand the eye-related symptoms that vision-corrected patients experience. The NSIGHT data provided valuable information on how often patients experience halos and glare and the degree to which they found them bothersome. 

About half of the spectacle and contact lens wearers surveyed reported suffering from the symptoms of halos (52 per cent and 56 per cent, respectively) and glare (47 per cent and 50 per cent, respectively) more than three times a week. More than four of five patients who experienced these symptoms found them bothersome (84 per cent and 89 per cent for halo and glare, respectively). These findings indicate that the severity of symptoms associated with halos and glare is sufficient to impact patient satisfaction with prescribed vision correction methods. Given how bothersome they found halos and glare, (90 per cent for halos, 91 per cent for glare) patients reported either having no solution to the problem or none that was satisfactory. Moreover, the same percentage of patients (89 per cent for halos, 87 per cent for glare) expressed an interest in an intervention that more adequately addressed these symptoms.

Dr. Jeff Mungar is an optometrist and contact lens fitter based inOakville, On. “Impaired vision in low light situations can be caused by a number of eye conditions, including halos and glares,” he says. “As the pupil dilates it throws light rays out of focus creating glare and halos as well as blurring.”

Mungar says that while aspherical lenses have been around for some time, he hasn’t found a product better than Bausch + Lomb’s PureVision 2 HD for low light conditions. “It corrects each Rx through the full range and so is more precise in eliminating the spherical aberration, resulting in crisp, clear vision. As just one example, I refit a woman who had been wearing a spherical disposable. While I couldn’t correct her to 20/20, she saw one line better on the chart because the spherical aberration was corrected. With this product we have reduced halos and glares along with excellent lens breathability and high levels of oxygen transmissibility. It’s a comfortable, moist, easy-to-use lens that not only improves vision but also leaves the wearer with healthy white eyes, devoid of strain. I recommend that eyecare professionals discuss vision in low-light situations with their patients to help ensure that appropriate solutions are identified for those experiencing halos and glare.”

The PureVision 2 HD is available for those who don’t require astigmatism correction. “If the patient has more than .75 units of astigmatism he or she needs an astigmatic corrective lens,” notes Mungar.

With the road safety implications of wearing regular contact lenses now understood, thanks to Dr. Chu’s study, one wonders if a massive public and professional education program is in order. Surely we would all have a lot to gain.



[i] The Effect of Presbyopic Vision Corrections on Nighttime Driving Performance, by Byoung Sun Chu, Joanne M. Wood, and Michael J. Collins, IOVS September 2010 51:4861-4866; published ahead of print April 7, 2010, doi. www.iovs.org.

 

The Truth about Soft Daily Disposables

By Janice Schmidt

Are you a golden fitter? Have you been around for a while and are now in the golden years of fitting contact lenses? If so, you are not alone. If you speak with the College of Opticians of Ontario or any regulatory college across Canada you will learn that many opticians face retirement in the next few years.

We golden fitters have seen it all – from the introduction of soft conventional lenses to today’s daily disposable soft contact lenses. And we have to ask whether soft daily disposable lenses are the answer, given that we deal with the pathological conditions created by hypoxia/anoxia (which in most cases, are directly related to the patient’s failure to look after their lenses properly).

I believe that soft daily disposable lenses are the answer for soft lens patients. However, we still have a way to go before they become 100 per cent worry-free.

The soft contact lens market is growing, and sales of soft daily disposable lenses are increasing faster than any other modality of wear or lens material. Sales were around 27 million in 2008, growing to 34 million in 2010.

This modality of wear offers definite benefits to patients and practitioners alike. At the same time, wearing contact lenses enhances the evaporation of the precorneal film (tear layer) and disrupts the proliferation, migration and exfoliation of corneal epithelial cells. Research shows that contact lenses can actually damage the surface epithelium and expose underlying cells. In fact, contact lens patients are at an 80 per cent risk for eye infections because of the breakdown in surface epithelium.

Although the surface epithelium is constantly bombarded by invasive microorganisms, eye infections in non-contact-lens wearers are rare. That’s because our eyes’ natural defense mechanisms are superior to the microorganisms that try to invade the cornea. But once you place a contact lens on the eye you break the balance between the bio-burden – the number of microorganisms on the ocular surface and the natural defense mechanisms – which leaves the eye at risk.

Having said all that, will I stop fitting contact lenses? Definitely not, because so many contact lens patients benefit from their superior visual acuity.

We just need to be realistic in our approach to dispensing contact lenses. Soft daily disposable lenses are designed for ocular health and represent one of the best options available to wearers but compliance remains an issue. Soft daily disposables are the most-complied-with modality of wear but 12 per cent of patients still keep them longer than they should. So if your practice is based solely on dispensing soft daily disposables remember that your patients are not free from the risk of infection. This is where we need to be diligent and get to know our patients better.

Research done by Stapleton, Holden and colleagues in Australia in 2004, showed that two in 10,000 soft daily disposable lens wearers developed an eye infection, compared to 1.7 in 10,000 wearers of frequent replacement lenses worn on a daily basis (bi-weekly or monthly). In other words, there was no significant difference in the incidence of infection between the two types of lenses. Soft daily disposable lenses were supposed to eliminate risks associated with contact lens wear but they actually increased the risks in non-compliant patients, based on the study results.

How well do you know your patients? Does the software on your office computer allow you to track their contact lens purchases? Do you call patients for rechecks and reorders? Does a red flag show up when a patient has not ordered lenses for a while?

You need to ask your soft daily disposable patients the following questions:

• Do you reuse your daily lenses?

• If the answer is yes, where do you store them – in the blister pack containing the same packaged solution?

If your patient answers yes to either of the above questions they are at risk and so are you. Why not provide them with a case and a MPDS solution? The soft disposable lens won’t survive – they are designed not to last – but at least the patient will be safer if they keep them for two or three days.

We can control what we tell our patients but we can’t control what they do. So if they admit to keeping their lenses longer than they should let’s be proactive and provide them with a means to care for them better. In a perfect world soft daily disposables are the right answer and if we can get them to improve compliance it will become a win-win situation for everyone.