MULTIFOCAL LENSES

Multifocal Lens Decision-Making 101

How to choose and best utilize the available soft and GP multifocal lens options.

By Edward S. Bennett, OD, MSEd, FAAO, & Thomas G. Quinn, OD, MS, FAAO

Advancements in multifocal contact lens designs, and greater understanding of how to utilize them, are allowing wearers of these lenses to experience unparalleled visual performance. The timing couldn’t be better. Recent data suggests that there are more than 100,000 presbyopic patients in the United States, representing 33.2% of the population (U.S. Census Bureau, 2012).

Clearly, many patients are poised to benefit from multifocal contact lens wear. This article will review what’s out there, and it will share tips on how to best utilize these innovative tools.

Growth in Multifocal Usage

Market research finds that 72% of practitioners prefer multifocal contact lenses for their presbyopic patients, with 20% preferring monovision and 8% over-spectacles (Nichols, 2014). This same source finds that 33% of practitioners believe that multifocal contact lenses have the greatest growth potential of all lens designs and modalities currently available, second only to daily disposable contact lenses.

This enthusiasm for multifocals is supported by science. In numerous head-to-head studies comparing multifocals with monovision, approximately 70% of those tested preferred the performance of multifocals (Johnson, 2000; Situ et al, 2003; Richdale et al, 2006; Woods et al, 2009).

Making Introductions

Simply stated, the best multifocal contact lens candidates are those presbyopes who may enjoy the cosmetic benefits and/or visual freedom that accompanies this form of correction. Those already wearing contact lenses prior to the onset of presbyopia are prime candidates. Personality traits associated with presbyopic multifocal contact lens success have included openness, agreeableness, and conscientiousness (Dinardo, 2014).

The highest incidence of first-reported symptoms from presbyopia is in persons 42 to 44 years of age (Kleinstein, 1987). Although eyecare providers are aware of this unavoidable development, many patients are surprised by it. Prepare your contact lens-wearing patients for presbyopia before symptoms develop. It is not uncommon for newly presbyopic myopes to discover that they can improve their near vision by removing or looking under their glasses. As this is not so easily accomplished while wearing single vision distance contact lenses, some patients may gradually gravitate to full-time spectacle wear. This potential for contact lens dropout can be avoided quite easily with early patient education. Of course, mentioning that you have available options, including multifocal contact lenses to restore their near vision when the need eventually arises, is quite reassuring to pre-presbyopic patients.

Presenting the Options

With few differences, the message communicated to single vision contact lens- and spectacle-wearing presbyopes is similar. The quality of vision is reported to be viable for most activities with all forms of multifocal contact lenses (Benoit, 2013); as multifocal contact lens wearers, we both concur with this statement. In fact, blessed with the knowledge that most designs incorporate multiple powers within the pupil at the same time (i.e., “simultaneous vision”), it is easy for non-presbyopic fitters (or non-contact lens-wearing presbyopic fitters) to have reservations about the potential for visual compromise with these designs. However, these concerns are often unwarranted. A recent study by Dinardo (2014) found that high visual demands and significant induced aberrations may not be much of a factor in multifocal contact lens success. It was also found that prior contact lens wear is not as influential for success as you might think.

The first step is to determine what patients’ goals are. This will certainly have a significant impact on what correction modality (if any) you recommend for a given patient. Have them rank distance, intermediate, and near demands, then focus in particular on meeting their top two demands. The impact of electronic devices such as computers and cell phones, which require good intermediate vision, has been significant, as most individuals use more than one digital electronic device for most of the day (Vogt, 2013). Often, simply satisfying that need results in a satisfied and successful multifocal contact lens wearer.

There is give-and-take with any form of presbyopic correction. Spectacle wear over single vision contact lenses provides good vision at distance, but significant inconvenience when correcting for near; likewise, patients are typically not motivated to wear spectacles for their primary daily activities. Monovision, once the predominant contact lens correction for presbyopia, has been relegated to a secondary option as multifocal lenses continue to progress and provide better overall quality of vision. For any patients wearing monovision lenses, we recommend providing a prescription for over-spectacles for critical distance tasks (e.g., driving).

As stated earlier, multifocal contact lenses outperform monovision in the majority of cases. Therefore, multifocal correction is the option that we emphasize for the great majority of presbyopic patients. However, even with these sophisticated devices, some give-and-take is inherent. We like to employ the “sandwich” approach as a means of setting proper expectations for multifocal lens performance. Initially indicate that a nice advantage of this option is the ability to see well for important day-to-day activities without the need for glasses. Then communicate that the vision may not be the same as with glasses due to—in most cases—multiple corrections in front of the eye at the same time. Finally, indicate that the goal is to provide a good balance of visual correction in the contact lenses. As these lenses are designed for patients’ unique visual demands, it may take some initial adaptation compared to single vision lenses; a lens change or two may be necessary to reach the desired level of satisfaction.

Always mention to patients that over-spectacles may be beneficial for occasional tasks (e.g., perhaps plus-power lenses for reading fine print, or minus-power lenses for night driving) although most multifocal contact lens wearers do not require them. In addition, multifocal contact lenses are typically not a good option if patients are hesitant about possible compromises or fees, do not appear to have realistic expectations (typically pertaining to vision), or are very satisfied spectacle wearers.

The Multifocal Options

Multifocal contact lenses are now available in a multitude of lens types and designs. Table 1 lists the pros and cons of each of these options.

Not surprisingly, the vast majority of contact lens-wearing presbyopes wear soft lenses, either soft multifocals (40%), soft monovision (31%), or soft distance correction with over-spectacles. GP bifocals/multifocals represent a small percentage of the market. At present, hybrid and scleral multifocals also represent a very small percentage of the market (Nichols, 2014).

If a newly presbyopic patient is already wearing contact lenses, the simplest approach is to stay in that lens type (e.g., soft, GP, or hybrid) as you move to a presbyopic design. However, changing the lens type may be warranted if important aspects of performance are not being met by the habitual design. A good example may be the presence of uncorrected astigmatism. However, any time change is introduced, take time to inform the patients how they will benefit. This will promote better patient cooperation, particularly during times when an adaptation process or multiple changes may be needed to achieve success.

Soft Multifocals Although soft multifocals typically employ center-near optics (there are exceptions, as described below), which can result in reduced contrast sensitivity function at near (Gifford et al, 2013), overall patient satisfaction is high, notably in soft lens wearers who are entering presbyopia. Here is a quick overview of what is offered by the major soft lens manufacturers.

Alcon The Air Optix Aqua Multifocal monthly replacement lens has a center-near aspheric design, available in three add powers.

Alcon now offers this same design in a daily disposable modality, the Dailies AquaComfort Plus Multifocal, employing the same material used in the daily disposable single vision lens of the same name. In the Alcon family of lenses, this lens joins the Focus Dailies Progressive daily disposable multifocal that has been available for some time.

Bausch + Lomb Bausch + Lomb’s (B+L) SofLens Multi-Focal was followed by the release of the PureVision Multi-Focal, which employed essentially the same optics, but in a silicone hydrogel material. B+L has recently released the PureVision2 Multi-Focal, which features a design quite similar to its predecessors, but is manufactured with a thin edge and highly repeatable, precise optics. B+L reports that these changes result in not only improved comfort, but better visual performance at virtually all distances.

CooperVision CooperVision’s trademarked Balanced Progressive Technology has been employed in the Frequency 55, Proclear, and Biofinity Multifocal lenses. The Frequency Multifocal was discontinued in October 2013. These designs feature the D lens (center distance) and N lens (center near) combination that has performed well on many patients.

Its monthly replacement Proclear EP lens option, a center-distance aspheric design, targets incipient presbyopes and those who suffer eye fatigue with prolonged near tasks. The Proclear 1 Day Multifocal, a center-near aspheric design, provides another daily disposable option. The lens comes in one nominal add power. When fitting patients who have a spectacle add of +1.25D and above, CooperVision recommends increasing plus in the nondominant eye to achieve good visual performance.

Vistakon, a division of Johnson and Johnson Vision Care Inc. Perhaps the first soft multifocal lens to have an impact in the marketplace was Vistakon’s Acuvue Bifocal. This lens was recently discontinued (effective December 31, 2013) in favor of the company’s newer Acuvue Oasys for Presbyopia. A center-distance biased design, this lens is available in three add powers. It is the only multifocal lens offered by a major supplier that is recommended for two-week replacement.

Sauflon Because a daily disposable option can benefit presbyopes who have no or low astigmatism and who desire the convenience and/or benefits of new, clean lenses every day, Sauflon recently introduced a daily disposable multifocal to the U.S. market to join those offered by Alcon and CooperVision. The Clariti 1day multifocal lens is a silicone hydrogel offering in a center-near design. It is offered in a low and high add power.

Specialty Soft Multifocals Custom soft multifocals are increasingly being offered, usually by smaller laboratories. These lenses often feature powers not widely available, including extremely high plus or minus, and/or astigmatic correction. A representative example is the SpecialEyes 54 Multifocal Toric, which is available in base curve radii ranging from 6.9mm to 9.5mm, diameters ranging from 12.5mm to 16.0mm, powers ranging from plano to ±25.00D, add powers as high as +4.00D, and cylinder powers from –0.50D to –8.00D in full-circle axes (Pfeil, 2012).

Although the combination of toric and multifocal powers can compromise optical quality, a recent study (Madrid-Costa et al, 2012) found that the Proclear Multifocal Toric provided similar outcomes to the Proclear Toric (with over-readers), with only slight decrements in distance and near visual acuities as compared to the toric-only design.

Several laboratories offer lenses manufactured in Contamac’s Definitive latheable silicone hydrogel material, resulting in high-Dk soft lenses with any conceivable astigmatic power and axis correction.

GP Multifocals GP multifocals essentially can be grouped into two categories: non-segmented or segmented. Non-segmented designs are non-ballasted and are either aspheric (front, back, or a combination), concentric, or a combination of both; segmented designs are prism-ballasted. A searchable database of GP multifocal lens designs and manufacturing laboratories is available at http://apps.gpli.info/asp/search.aspx.

GP aspheric (or aspheric-concentric combination) designs can meet most patient needs, especially pertaining to good vision at all distances. Every laboratory offers one or more of the higher-add designs that have been introduced in recent years. As these are center-distance designs, presbyopic patients who have large pupils (in normal room illumination), typically ≥6mm, are not good candidates.

Segmented, translating bifocal designs have become less popular in recent years due to innovations in aspheric designs—notably higher add power availability—and the introduction of numerous segmented multifocal designs with intermediate-correcting capability. For patients desiring excellent, uninterrupted vision at distance and near, this still remains the best available option. Initial comfort remains the most important limitation of these designs, although both aspheric and segmented designs achieve greater initial comfort compared to spherical GP designs, likely because multifocal lenses—when properly fit—move less with the blink compared to spherical lenses (Bennett, 2005).

Hybrid Multifocals Hybrid lenses, which have a GP center and soft skirt, have been available for decades. Early designs had problems with splitting at the GP/soft junction. In our experience, this is rarely, if ever, an issue with today’s hybrid designs.

SynergEyes manufactures the only widely available hybrid lens designs today. SynergEyes’ multifocal lenses have evolved since introduced in 2008. Their original offering, the SynergEyes Multifocal, features a discrete central near zone available in two zone sizes and various add powers. It remains available, but mostly for patients already successfully wearing the lens (Curio, 2014).

The Duette Multifocal was introduced into the marketplace in 2011. This lens offers higher oxygen transmission through both the GP center and the soft skirt; it also features a reformulated design. One of the challenges encountered with the original Synerg-Eyes Multifocal was lens binding on the ocular surface. The Duette line of products has a redesigned junction area that has greatly reduced this problem. The Duette Multifocal also offers a totally different approach to multifocal optics compared to its predecessor, employing center-near aspheric optics. Instead of specific add powers, this lens offers two add sizes: small or large.

In February 2014, SynergEyes introduced the Duette Progressive lens. This lens is manufactured on the same platform as the Duette Multifocal, but offers new optics. The Duette Progressive is available in one zone size (3mm) and three add powers: low (+1.00D), medium (+1.75D), and high (+2.50D) (Figure 1).

Figure 1. The Duette Progressive lens design from SynergEyes.

In addition to design modifications, there has been an evolution in the fitting approach with Duette products. Basically, fit the central rigid portion of the lens just as you would a GP lens and fit the surrounding soft skirt as you would a soft lens (Quinn and Davis, 2012). Look for the flattest fit that provides good comfort and vision. SynergEyes is moving away from diagnostic fitting sets and recommends lenses be ordered empirically based on the patient’s central corneal shape measurements and spectacle prescription.

Scleral Multifocals A viable entry into the multifocal contact lens toolbox is scleral multifocal designs. Although they command a higher fee compared to other options, and the handling is more complex, they also offer benefits such as comfort similar to soft lenses and the optical quality—and resulting quality of vision—often achieved by GP corneal lenses (Barnett and Messer, 2013; Watanabe et al, 2013; Woo, 2013; Potter, 2012). Certainly for irregular cornea patients—many of whom are not good candidates for any other multifocal design due to fit or vision concerns—these designs may represent the only viable option. As they do not translate, center-near optics predominate with these designs.

The Decision-Making Process

Several factors are important when deciding to fit presbyopic patients into one of the available multifocal contact lens modalities (Table 1). These factors include patients’ vision at distance, near, and intermediate as well as toric parameter availability when indicated, initial comfort, ease of fitting, cost, and ease of care and handling.

Certainly, a current spherical soft lens wearer has a high probability of succeeding with a soft multifocal lens, but consider the hybrid and/or GP multifocal options if reduced vision becomes problematic. Likewise, scleral multifocals have the benefits of initial comfort and great vision, but care, handling, and cost issues must be initially discussed with patients. For post-refractive surgery patients, front-surface aspheric GP multifocals (with a reverse geometry back surface) are often indicated. Soft daily disposable multifocals provide a great option to soft presbyopic lens wearers who desire the convenience and variable wear option provided by this modality.

Spectacle-wearing presbyopes should definitely consider multifocal lenses. The best option for these patients depends upon whether they require an astigmatic correction, are concerned about initial comfort, or have critical vision demands. A GP option would be preferable for high astigmats, although the newer custom silicone hydrogel soft toric multifocals can be successful for patients who do not have critical vision demands.

A good guide for specific multifocal design applications for different levels of presbyopia is the Hom-Gallagher-Eiden Multifocal Selection Grid (Bennett and Henry, 2012). Table 2 presents a summary of representative cases.

Clinical Tips

1) Compare Ks and Refractive Cylinder to Guide Lens Selection If an astigmatic patient has central corneal toricity equal to the vertexed-spectacle cylinder, start with a lens that can utilize the tear layer to correct the astigmatism. Examples would be a GP lens, either corneal or scleral, or a hybrid lens. If central corneal toricity does not equal the vertexed-spectacle cylinder, a wide variety of approaches can be employed including a soft toric multifocal, toric soft monovision, or toric soft distance correction in both eyes with over-readers.

2) Defining Success When evaluating multifocal lens performance, it is important to recognize that patient satisfaction may not be accurately communicated simply by visual acuity measurements. One study found objective measures, such as visual acuity, were higher for monovision, but multifocal lenses were preferred overall by these same subjects, especially for activities such as night driving, television viewing, and computer use (Woods et al, 2009). This suggests that patient feedback is perhaps the best barometer to use when assessing patient response to multifocal contact lenses.

3) It Gets Better over Time Always tell patients that the vision will improve and that what they are experiencing at dispensing is the worst case scenario as the eyes adapt to multifocal lens optics. In fact, one study found a clinically significant improvement in vision after approximately 15 days with a multifocal soft lens as compared to monovision (Fernandes et al, 2013). This study also concluded that simultaneous multifocal contact lenses can potentially provide a better balance of real-world visual function because of minimal binocular disruption compared to monovision lenses.

4) The Pupils Are the Windows to Multifocal Lens Success Measuring the pupil size in three separate illumination levels (i.e., bright light, dim light—using the cobalt blue filter on either the slit lamp’s dimmest setting or a topographer—and normal room illumination) has been recommended (Young et al, 2013). Ask patients what lighting environment they are in most frequently and adjust the center zone accordingly if it is available in multiple sizes.

5) Mapping Your Way to Success Corneal topography is an effective tool when prescribing lenses for presbyopia. The most basic measurements of surface curvature, corneal diameter, and pupil size can be performed using topography as part of the fitting process for all presbyopic lenses (Norman, 2013). In addition, taking maps over the lenses during follow-up examinations to determine where the optics are in relation to the line of sight can explain many visual complaints that patients describe.

6) Distance Prevails If you are in doubt as to which soft multifocal lens to select, use the lens(es) that would provide better vision at distance initially. It is better for patients to be initially symptomatic with near vision than with distance vision.

7) You Don’t Have to Be Even Uneven add powers (or high and low adds) are often recommended and successful when fitting soft multifocal lenses.

8) A Journey to Good Vision Once the lenses have been dispensed, have patients walk around your office and perform typical daily tasks (e.g., look at a cell phone, read a magazine, look at a computer, look out the window at a distance, etc.). Have them report what looks good and what is blurry. You can save considerable time by making a small adjustment at this time, which can result in large dividends.

Resources

There are a number of resources to assist in lens selection, fitting, and troubleshooting multifocal contact lenses. Many of the laboratories have fitting guides, calculators, and even webinars to gain a greater understanding of how to fit specific soft or GP multifocal lens designs. The most important resource for GP multifocals is the laboratory consultants, who can assist in all aspects of the fitting process.

In addition, the GP Lens Institute (GPLI) has introduced a GP presbyopic lens module titled: “Building Your Practice with GP Bifocals and Multifocals.” This module has 17 total programs—all online—including PowerPoint presentations on presenting options, fitting and evaluation, marketing contact lens services to your presbyopic patients, and a fee calculator for practitioners. It also has an application and removal video series as well as scripts to answer common patient questions for staff members. In addition, there are webinars—both forthcoming and archived—pertaining to GP multifocal contact lens fitting and problem-solving. Table 3 lists where to find soft and GP multifocal resources.

Summary

It is evident that multifocal lens designs will only continue to improve. New technologies are being explored, some with optics much different from those presently in use. Older technologies are being updated with improved optics and better lens materials (Norman, 2014). The arrow will continue to point upward for multifocal contact lenses versus other lens options for presbyopia. If you are proactive in fitting these designs, not only will your practice exhibit greater growth, but patient satisfaction will be higher as well, notably among patients who were not even aware that they could wear contact lenses to correct their presbyopia. CLS

For references, please visit www.clspectrum.com/references.asp and click on document #221.

Dr. Bennett is assistant dean for Student Services and Alumni Relations at the University of Missouri-St. Louis College of Optometry and is executive director of the GP Lens Institute. You can reach him at ebennett@umsl.edu.

Dr. Quinn is in group practice in Athens, Ohio. He is an advisor to the GP Lens Institute and an area manager for Vision Source. He is an advisor or consultant to Alcon and B+L, has received research funding from Alcon, AMO, Allergan, and B+L, and has received lecture or authorship honoraria from Alcon, B+L, CooperVision, GPLI, SynergEyes, and STAPLE program. You can reach him at tgquinn5@gmail.com.