By Evra Taylor

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.

By Evra Taylor

Demographically 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.

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.