There is no doubt that presbyopes are interested in contact lenses. According to a 2008 Gallup poll, more than six in 10 adults between the ages of 35 and 49 who wear contact lenses and eight in 10 lens wearers over the age of 50 say that they are interested in bifocal or multifocal contact lenses.1 In our experience, most patients who wear contact lenses are highly motivated to stay in them, and they are typically willing to tolerate some visual tradeoffs for the lifestyle benefits of contact lens wear, as long as it’s comfortable.
But, that’s the rub—comfort is a huge issue for presbyopes. Not surprisingly, the data show that the primary reasons for contact lens dissatisfaction and discontinuation (at any age) are ocular dryness and discomfort.2-4 Moreover, these symptoms affect contact lens wearers far earlier than we once thought. One study found that more than four out of 10 hydrogel lens wearers in their 20s already begin to experience marked end-of-day discomfort.5
By age 40, more and more lens wearers are struggling with dry eye brought on by age, hormonal changes, lifestyle and environment, so moving them into presbyopic designs that offer good vision but poor ocular comfort is a recipe for contact lens dropout. For this reason, we have previously advised emerging presbyopes to ignore the condition as long as possible, until near vision become truly bothersome. When that happened, we would typically move patients into monovision with a comfortable lens material, such as senofilcon A. Only when they couldn’t tolerate monovision would we go to a multifocal design, such as the SofLens Multifocal (Bausch + Lomb). Early on, we tried both the Biomedics EP, a CooperVision hydrogel lens designed for emerging presbyopes, and Bausch + Lomb’s PureVision Multifocal lenses, the first silicone hydrogel for presbyopes. While vision for some was satisfactory, the degree of comfort was a challenge for many of our presbyopes.
Designs on Presbyopia
Contact lens manufacturers have always struggled to develop lenses that can provide sharp optics at all distances without visual artifacts. In soft lens designs, there have been three basic approaches: aspheric, ring-based and multifocal monovision. Each has advantages and disadvantages. The aspheric category has been lighting- and pupil size-dependent. Ring-based designs compensate better for lighting and pupil size, but may cause ghosting or halos.
Studies comparing multifocal contact lenses to other forms of presbyopic correction have been inconclusive. One recent study, for example, found that monovision performed better than a center-near aspheric simultaneous vision multifocal contact lens of the same material, but that the multifocal lenses may have achieved a better balance of real-world visual function.6 Another study compared progressive spectacle lenses to a new multifocal contact lens. At the end of this crossover study, a large majority (78%) of subjects said that the combination of a multifocal contact lens and progressive spectacles met their vision correction needs better than either modality alone.7 The patients preferred contact lenses for the majority of tasks because they offered more natural, active vision and gave patients more control over their appearance. These findings align with our experience that contact lens patients really do desire to limit their dependence on spectacles.
Material Advantages
With about 95% of our single-vision contact lens patients in silicone hydrogel lenses, we are firm believers in the advantages of this material, both for ocular health and comfort. Silicone hydrogel materials promote end-of-day comfort, which is key for those struggling with contact lens-related dryness.
Studies have shown that hydrogel contact lens wearers reported increasing struggle with lens wear and more negative ratings of their lens wearing experience than silicone hydrogel wearers.5 They are also more likely to struggle in challenging environments and to discontinue lens wear altogether vs. silicone hydrogel wearers.
Refitting hydrogel wearers into silicone hydrogel materials, such as lotrafilcon B or senofilcon A, significantly reduces the frequency and severity of contact lens-related dryness symptoms and can improve comfort and wearing time, even in challenging environments.8-10
But, we have had very limited options in multifocal designs made from silicone hydrogel materials. As noted previously, the first lens on the market is not as comfortable initially, though long-term comfort is generally good. Newer silicone hydrogel multifocal contact lenses offer greater hope for a healthier, more comfortable transition to presbyopia for our contact lens patients.
Age and Stage
The Acuvue Oasys for Presbyopia lens, in its current parameters, is designed for myopic and hyperopic presbyopes (+6.00D to -9.00D). Originally released in low and mid add powers for those who require only +0.75D to +1.75D of add, a higher add power has also just been released, extending the range up to +2.50D.
This lens can be a good option for advanced presbyopes who are wearing distance contact lenses, using reading glasses for near and reaching the point of needing two pairs of readers—one for near and one for intermediate. While such patients may not reach full spectacle independence, they are often thrilled simply to gain arms-length vision and eliminate one pair of readers.
The ideal scenario, in our experience thus far, is to move contact lens patients into this lens as soon as they begin to notice near vision problems in their late 30s and early 40s. It is an easy transition because many of them are already wearing senofilcon A lenses, and the comfort level and feel of the lenses is quite similar. They have a chance to adapt to multifocal optics, while they still have some natural accommodation and only need a low add. If we can successfully prevent dropout at this point, patients will be well-positioned for continued success as they become more presbyopic. CooperVision’s Frequency 55 or ProClear Multifocals and Bausch + Lomb’s SofLens Multifocal offer higher adds when advanced presbyopes require them.
We look forward to trying other silicone hydrogel materials that can provide end-of-day comfort and a full range of vision for more mature presbyopes. More toric multifocal options would also be welcome.
Fitting the Presbyope
Clinicians who would like to be successful at fitting presbyopes must first check their own expectations—prior to establishing realistic expectations among patients. A common mistake that doctors make is to assume that one presbyopic lens will fit everyone. It’s fine to have a “go-to” lens, as long as you understand that you often have to go to option B or C as well. Another common mistake is the expectation to achieve perfect vision at all distances on the first try. Multifocal fitting is a balancing act, and we often need to make adjustments after patients use their lenses for real-world tasks.
The key to improving success and decreasing chair time is selecting the best starting lens. A careful “full plus” subjective refraction that yields the best sphero-cylindrical correction followed by derivation of the spherical equivalent is a great starting point. The spherical equivalent should then be optimized by the addition of plus or minus.
With its new presbyopic lens, Vistakon has tried to make multifocal fitting less of an art form, reducing the number of visits needed. The fitting system for this lens was clinically validated through nine substantive crossover trials involving nearly 900 patients, which is highly unusual.
Most multifocal lenses are introduced to the market with fitting guides based on theoretical testing, which then get considerably revised following clinical experience. The result of this validation process is a very intuitive tool that eliminates much of the experimenting the doctor has to do, both in choosing the initial lens pair and in deciding what changes to make at the next visit.
Proactive Guidance
We tell patients to expect to lose some of the crispness of fine detail with any multifocal lens when switching from spectacles. You have to be direct with your patients. We state, “You will likely get most of what you need, most of the time. But, your vision will probably not be as sharp as your glasses prescription.” Another way to judge whether a patient will be successful in presbyopic lenses is to ask two questions:
• Do you find glasses to be a hassle? (Gets at the motivation to succeed with contact lenses.)
• Would you be willing to accept a contact lens that meets your needs for 80% of your daily tasks? (Sets up appropriate expectations.)
Seize the Opportunity
For practitioners, there is great opportunity in the presbyopic lens market. The category ought to encompass not only contact lens wearing myopes and hyperopes who have become presbyopic, but also all those emmetropes and latent hyperopes who first experience the need for vision correction after age 40. Instead, the number of presbyopic lens wearers is only one-tenth the number of spherical contact lens wearers—and that hasn’t changed much over the past 10 years.
Finally, we are beginning to conquer comfort, the last frontier in multifocal contact lenses. If you can keep emerging presbyopes comfortable, you can keep them happy with today’s multifocal options.
Dr. Castleberry is President and CEO and Dr. Tran is Chief of Staff of Plano Eye Associates in Plano, Tex. Both doctors also serve as adjunct faculty for the University of Houston College of Optometry. Contact them at (972) 985-1412 or www.planoeye.com. Neither of the authors have a financial relationship with any of the companies mentioned in this article.
1. Multi-Sponsor Survey’s 2008 Gallup Study of the Consumer Contact Lens Market. 2008.
2. Richdale K, Sinnott LT, Skadahl E, Nichols JJ. Frequency of and factors associated with contact lens dissatisfaction and discontinuation. Cornea. 2007 Feb;26(2):168-74.
3. Pritchard N, Fonn D, Brazeau D. Discontinuation of contact lens wear: a survey. Int Contact Lens Clin. 1999 Nov;26(6):157-62.
4. Schlanger JL. A study of contact lens failures. J Am Optom Assoc. 1993;64:220-4.
5. Chalmers RL, Hunt C, Hickson Curran S, Young G. Struggle with hydrogel CL wear increases with age in young adults. Cont Lens Ant Eye 2009;32(3):113-9.
6. Gupta N, Naroo SA, Wolffsohn JS. Visual comparison of multifocal contact lens to monovision. Optom Vis Sci. 2009 Feb;86(2):E98-105.
7. Data on file. Vistakon.
8. Young G, Riley CM, Chalmers RL, Hunt C. Hydrogel lens comfort in challenging environments and the effect of refitting with silicone hydrogel lenses. Optom Vis Sci. 2007 Apr;84(4):302-8.
9. Chalmers R, Long B, Dillehay S, Begley C. Improving contact lens related dryness symptoms with silicone hydrogel lenses. Optom Vis Sci. 2008 Aug;85(8):778-84.
10. Riley C, Young G, Chalmers R. Prevalence of ocular surface symptoms, signs, and uncomfortable hours of wear in contact lens wearers: the effect of refitting with daily-wear silicone hydrogel lenses (senofilcon A). Eye Contact Lens. 2006 Dec;32(6):281-6.
