SOFT AND GP MULTIFOCALS
Contemporary Multifocal Contact Lens Primer
Presbyopes want multifocal contact lenses, and today's multifocal lens options are easier to fit than ever.
By Edward S. Bennett, OD, MSEd, FAAO, & Vinita Allee Henry, OD, FAAO
Historically, multifocal contact lenses, notably soft lens designs, have been perceived as complex and providing limited success. But the truth is, they are relatively easy to fit, enjoy higher—if not much higher—success rates compared to 10 to 20 years ago, and they represent the best option for the majority of presbyopic patients who are interested in contact lens wear.
Presbyopes, in general, appear to often be ignored as candidates even when contact lenses may be a very good option for them. A recent international survey concluded that there is a significant underprescribing of contact lenses for the correction of presbyopia (Morgan et al, 2011). Multifocal contact lenses in particular are underutilized, and this often results from patients being unaware that this option exists. In a survey of 500 incipient presbyopic contact lens wearers, only 8 percent were told by their practitioner about multifocal contact lenses when they first complained of poor near vision (Studebaker, 2009). Similarly, the most commonly asked question on a popular consumer contact lens site, www.contactlenses.org, pertains to obtaining information about multifocal contact lenses, often because the consumers had been told that multifocal contact lenses are not a viable option for them.
Underutilization = Opportunity
One reason we feel qualified to write this article is that we are both satisfied multifocal contact lens wearers (i.e., E.B. wears GP multifocals and V.H. wears soft multifocals) who wore single vision lenses prior to presbyopia. We understand the benefits of good vision at multiple distances as well as the visual freedom achieved with minimal to no necessary spectacle wear. It has been reported that more than 90 percent of contact lens wearers in the 35 to 55 age group are, like us, committed to continuing contact lens wear (Edmonds and Reindel, 2003). The good news is that the contact lens market in the United States is expected to increase to almost 34 million wearers in the next decade, and individuals 50 years of age or older should comprise the single largest age component of this group, equal to 28 percent of all wearers or 13.5 million people (Studebaker, 2009). What all of this information spells out loud and clear to eyecare practitioners is one word: “opportunity.”
What About Monovision?
Monovision will always be a contact lens option for presbyopes, but advancements in contact lens technology make this option a secondary one in today's contact lens practice. Studies directly comparing monovision to both soft (Benjamin, 2007; Richdale et al, 2006; and Situ et al, 2003) and GP (Johnson et al, 2000) multifocal contact lenses have shown that multifocal contact lenses are preferred by 68 to 76 percent of wearers. Additionally, when the visual performance of four different presbyopic lens corrections (i.e., progressive addition spectacles [PALs], a GP multifocal lens design, a soft bifocal lens design, and monovision) were compared—including high- and lowcontrast acuity and contrast sensitivity function—the GP multifocals were found to be similar to PALs, followed by the soft bifocals, with monovision finishing last in all categories tested (Ragagopalan et al, 2006).
What is particularly important for presbyopes is how they see in “real-world” situations. Woods et al (2009) compared monovision to a soft multifocal contact lens (Air Optix Aqua Multifocal, Alcon) in emerging presbyopes. Specifically, via the use of Blackberry technology, subjects rated their quality of vision in a variety of real-world situations—including daytime and nighttime driving and watching television—in addition to routine clinical testing. Whereas monovision performed better for examination room vision testing, the soft multifocal lens was clearly preferred in the real-world situations.
There does appear to be, however, a gradual shift toward multifocal contact lenses as the preferred modality for contact lens correction of presbyopic patients. Nichols (2012) reported that 67 percent of practitioners surveyed indicated that multifocal contact lenses were their preferred modality, with 23 percent indicating monovision and 10 percent preferring single vision lenses with a near correction in spectacles. This is compared to the findings of a similar survey three years prior that found 59 percent preferring multifocals, 27 percent monovision, and 14 percent single vision with reading glasses (Nichols, 2009).
New Contact Lens Designs and Developments
Soft Lens Designs
The soft multifocal contact lens market is dominated by the silicone hydrogel designs from the major manufacturers. The Air Optix Aqua Multifocal lens design is available in three add powers for either daily wear or extended wear and monthly replacement. It has a center-near design and compensates for the loss in accommodation by extending the depth of focus.
Acuvue Oasys for Presbyopia (Vistakon) likewise has three add powers and can be worn for either daily wear or extended wear. It is replaced every two weeks. It features a center-distance aspheric zone surrounded by alternating aspheric zones on the front surface.
PureVision Multi-Focal (Bausch + Lomb [B+L]) is a center-near, anterior aspheric multifocal available for daily wear or continuous wear. It is available in two add powers and is replaced monthly.
Biofinity Multifocal (Cooper-Vision) uses the company's Balanced Progressive Technology (i.e., “D” and “N” designs) that are also featured in its Proclear Multifocal. The D lens has a center-distance design while the N lens has a centernear design. Four add powers are available. The lenses can be worn for daily wear or extended wear, and monthly replacement is recommended. Cooper-Vision has changed its fitting recommendations, however: Unless the patient has small pupils, the company recommends starting patients with low (i.e., +1.00D to +1.50D) add powers with two D lenses. For individuals who have a low add and small pupils as well as for patients who need a higher add (i.e., +2.00D and +2.50D), the company recommends using a D lens and an N lens.
There is also a need in the market today for a frequent replacement silicone hydrogel multifocal toric lens for astigmatic patients. One option meeting this need was introduced by Art Optical via its partnership with Ultravision International Limited in the United Kingdom. Art Optical's Intelliwave soft lenses, available in the Definitive (Contamac) silicone hydrogel material, are available in both multifocal and toric multifocal designs for quarterly replacement. The latter design is especially welcome as it is a custom design available in both high sphere (i.e., ≤±20.00D) and high cylinder (i.e., ≤4.00D) powers in any cylinder axis. Intelliwave incorporates aberration control via wavefront technology.
Proclear Multifocal Toric (CooperVision) is a popular hydrogel multifocal lens for astigmats that combines the same design described for the Biofinity Multifocal with a toric design. It is available in a wide range of parameters.
An important factor with presbyopic contact lens wearers is the decrease in tear volume and potential increase in dryness symptoms with age. To meet this need, it is likely that we will see silicone hydrogel daily disposable multifocal lenses introduced in 2012. Although high-add power patients still remain one of the biggest challenges today, it is evident that improvements in lens designs and materials are meeting more of our presbyopic patients' visual needs.
GP and Hybrid Lens Designs
One of the most important developments in GP multifocal designs in recent years has been the emphasis on empirical fitting, which simulates a benefit of soft multifocals in that the first pair of lenses worn are in the proper lens powers to provide good initial vision. This is an applicable benefit with all aspheric and annular designs. One segmented, translating bifocal (BiExpert from Art Optical and Essilor) can be designed empirically if the refractive information as well as some anatomical measurements are provided including: horizontal visible iris diameter, pupil diameter, lower lid to lower pupil distance, palpebral fissure width, lower lid-limbus position, and lid tightness.
Many of the new designs and materials are meeting the important need of achieving add powers that will satisfy more mature presbyopes. Conforma has introduced its VFL3 HD-AP multifocal, which is a higher-add version of the company's back-surface VFL3 design that also incorporates some aberration control. There continues to be an increase in front-surface aspheric designs or combination aspheric-annular configurations. These designs not only minimize the corneal molding that is sometimes associated with steepbase-curve, posterior-only designs, but are also able to incorporate a high add on the front surface. This is complemented by high-refractive-index lens materials such as Optimum HR (Contamac) and Paragon HDS HI (Paragon Vision Sciences), which can incorporate a higher add power while optimizing centration because they have less mass compared to conventional materials.
GP manufacturers are also introducing presbyopic designs that meet the needs of highly astigmatic, keratoconic, and post-refractive surgery individuals. Blanchard offers Reclaim HD—which has front-surface multifocal optics—with a toric back surface, on all Rose K keratoconic designs, and on the company's Refractive Surgery Specific (RSS) post-refractive surgery design. Designs for post-refractive surgery patients are definitely important as more refractive surgery patients enter the presbyopic age range. In addition to Blanchard, several laboratories offer these designs, typically with a reverse geometry back surface and a front-surface multifocal correction. Valley Contax's LasikNear can be manufactured in any material, but high-index materials are recommended. Art Optical will launch a front-surface add, post-laser-assisted in situ keratomileusis (LASIK) reverse geometry design in the second quarter of this year.
An exciting area of potential GP multifocal application pertains to scleral designs. Combining the initial comfort of a scleral design with multifocal correction could entice new wearers into multifocal lenses. The Digiform and Tru-Scleral designs (Truform Optics) as well as the So2Clear Progressive (Dakota Sciences/Art Optical/Metro Optics) (Figure 1) have center-near designs, while the Dyna Semi Scleral (Lens Dynamics) has an aspheric design (Potter, 2012). Blanchard is also developing a multifocal scleral design.
Figure 1. The So2 Clear Progressive Design (Dakota Sciences/Art Optical/Metro Optics). COURTESY OF JASON JEDLICKA, OD
Another viable option, especially when comfort and/or centration are issues, is a hybrid design. SynergEyes introduced the Duette Multifocal in August 2011. This hybrid design is composed of a 130-Dk GP material surrounded by an 84-Dk silicone hydrogel skirt. The design is center-near with the add zone on top of a distance asphere. It features two add zone sizes and three skirt curve radii. SynergEyes recommends either Biotrue (B+L) or Aquify (Alcon) for the care regimen.
Finally, for patients who want continuous wear, the Menicon Z (Menicon) material is approved for continuous wear in multifocal designs.
Tables 1, 2, and 3 provide clinical pearls for general multifocal lens fitting, soft multifocal designs, and GP multifocals, respectively. Prominent contact lens practitioners, acknowledged at the conclusion of this article, contributed to these useful guidelines.
|General Multifocal Lens Fitting Pearls|
PATIENT SELECTION AND COMMUNICATION
1. Start them early—tell patients about multifocal contact lenses before they enter presbyopia and emphasize multifocal contact lenses once patients become presbyopic.
2. Yes there is compromise, but communicate it properly. Patients need to know that these designs often have multiple corrections in front of the eye simultaneously, and it is a “balancing act” (rather than a “compromise) between near and distance vision. Freedom from frequent spectacle wear is the benefit.
3. Have patients rank their goals for distance, intermediate, and near vision.
4. Indicate that spectacle wear over the lenses is possible but that the goal is to meet the patient's primary needs without spectacle use.
5. If the patient is hesitant about possible compromises, cost, etc. or simply does not have realistic expectations, do not fit.
1. Determine pupil diameter as accurately as possible under normal room illumination.
2. Determine the dominant eye in one of several ways: by having the patient indicate sighting with a telescope or camera or through a triangle made with their extended hands, or use a +2.00D lens alternated between eyes at distance—the blurrier eye is likely dominant.
3. Use the manufacturers' fitting guides for lens selection and problem-solving.
4. Once the lenses have settled, have patients perform relevant “real-world” tasks (i.e., view Smart- Phone, look at a computer, read a magazine, walk around the office to view at a distance, etc.).
5. Perform the over-refraction binocularly with the trial lens (often in the form of ±0.25D and ±0.50D flip lenses) over the eye.
6. Instruct patients to use good lighting when performing near tasks.
7. Instruct satisfied patients to return for follow up in no less than one week (time can vary with design) and tell them that vision tends to improve as their eyes adapt to the lenses.
|Soft Multifocal Clinical Pearls|
1. Start with the current refraction and add and correctly identify the dominant eye.
2. Allow 10 to 20 minutes for the lenses to settle prior to evaluation.
3. If in doubt about which lens design to select, use the lens(es) that would provide better vision at distance initially. It is better for the patient to be initially symptomatic with near vision than with distance vision.
4. When one soft multifocal lens design is unsuccessful, do not hesitate to try another design or even use two different designs.
5. Uneven add powers (or high and low adds) are often recommended and successful. If near vision is reduced, another option is to bias the nondominant eye with an additional +0.25D to +0.50D.
6. Modified monovision (i.e., a spherical distance lens on the dominant eye and a multifocal on the nondominant eye) can be a good choice to avoid the disadvantages of full monovision.
|GP Multifocal Clinical Pearls|
1. Communicate that these lenses move on the eye with the blink; therefore, it is a dynamic process—unlike spectacles—and it may take a lens change or two to achieve success.
2. Begin by fitting a few single vision GP wearers who have entered presbyopia. If they have a good lens-to-cornea fitting relationship, you can often achieve success with a front-surface add design. If the lens decenters superiorly, consider a back-surface aspheric design.
3. Whenever possible, fit these lenses empirically, especially with new GP wearers. If the first pair of lenses dispensed to a patient results in good vision, it is likely that they will be less aware of any comfort issues.
4. Pupil diameter is critical in lens selection. A patient who has ≥6mm pupil diameters in normal room illumination will not be a good aspheric candidate; a patient who has miotic pupils (i.e., ≤3mm) will need to progress into a higher-add design quickly if aspheric—and some annular—designs are fit.
5. Patients desiring uninterrupted near and distance vision would benefit from a segmented, translating design. Good candidates for these designs do not have flaccid or loose lids and have the lower lid positioned no greater than 1mm below the lower limbus.
6. If a segmented lens does not translate, or translates intermittently, select a 0.50D flatter base curve radius lens to increase the inferior edge clearance. If the lens is picked up too high by the upper lid with the blink, increase the prism by 0.50?.
7. Order the lenses warranted whenever possible.
8. Your best friend in the fitting process is a laboratory consultant.
Certainly the best time to mention multifocal contact lenses is before patients become presbyopic. If you can fit them as emerging presbyopes, you can always increase the add power over time as opposed to beginning with a higher-add patient who may be accustomed to spectacle lens wear or monovision. Likewise, do not be quick to switch to monovision. With today's multifocal designs, good binocularity can be achieved as well as satisfactory—if not excellent—vision at all distances. Always remember that multifocal contact lenses provide wearers with the often highly desired benefit (particularly if they have been single vision wearers) of freedom from spectacle wear for the tasks that they really like to perform. With this in mind, it is always important to make sure that they can see what is important to them under real-world conditions, such as looking at their SmartPhone, reading a magazine, looking at a computer screen, etc. The fitting process itself is actually relatively simple due to the introduction of improved designs and easy-to-use lens selection, fitting, and problem-solving cards available from each manufacturer.
A wealth of resources are available that are especially beneficial when fitting multifocal contact lenses; the ones mentioned here represent only a partial list of those available. Some manufacturers offer “wheels” to help with multifocal fitting. For example, Alcon's Air Optix Aqua Multifocal task wheel helps patients view real-world material such as a BlackBerry, computer screen, GPS, and a nutrition label while Vistakon's Acuvue Oasys for Presbyopia Stereo Precision Select wheel helps with troubleshooting patient symptoms (Figure 2).
Figure 2. Soft multifocal lens resources from Alcon and Vistakon.
In addition, there are a number of useful calculators that assist with the various designs, such as those from Vistakon (www.ecp.acuvue.com), SynergEyes (www.synergeyes.com), and Alcon (www.virtualconsultant.cibavision.com). Several companies provide useful consumer information and resources as well, notably B+L's web site www.presbyopesinyourpractice.com.
The most important resources for GP multifocals are laboratory consultants, who often troubleshoot the fitting of multifocal lenses in their respective designs on a daily basis, not to mention providing useful information on diagnostic sets, warranties, etc. Most of the laboratories have fitting guides, PowerPoint presentations, webinars, and calculators available as well. The GP Lens Institute has a number of resources including a narrated Power Point lecture on GP fitting and problem-solving, a case Grand Rounds Troubleshooting Guide with a number of unique GP multifocal cases, a Clinical Pearls Pocket Guide, and “Rx for Success,” which is a comprehensive module for educating practitioners, staff, and patients. It includes downloadable printed materials, numerous PowerPoint presentations pertaining to such topics as patient selection and fitting as well as a fee calculator. All of these resources are available at www.gpli.info.
The Decision-Making Process
It is evident that soft lenses, even specialty lenses such as multifocals, offer an easier fitting process that is attractive to busy practitioners. However, what must also be considered in the decision-making process is that GP multifocal lenses have improved dramatically, resulting in an easier fitting process. It's important to work with and achieve a good comfort level with a few soft multifocal designs and a few GP/hybrid designs so you learn which design works best for different types of presbyopic patients. Every practitioner who fits multifocal contact lenses has preferred designs based on the type of presbyopic patient. One such selection grid was developed by Drs. Milton Hom, Leslie Gallagher, and Barry Eiden (Table 4). It ranks their preferences based on whether distance vision, intermediate vision, or near vision is a priority for a given patient. It also provides their recommendations for patients who also need a toric prescription. Table 5 is a similar grid pertaining exclusively to GP multifocal selection. The contact lens multifocal market changes very dynamically, so these grids will also change as designs such as one-day multifocals and scleral GP multifocal designs become more available.
|Hom-Gallagher-Eiden Multifocal Selection Grid (All Lenses)|
|Bias||Low: +1.00D to +1.50D Spectacle Adds||High: +1.75D to Spectacle Adds|
|Distance||1. Proclear EP (CooperVision)
2. Acuvue Oasys for Presbyopia (Vistakon)
|1. Air Optix Aqua Multifocal (Medium Add) (Alcon)|
2. Biofinity Multifocal (CooperVision)
3. Two “D” Proclear Multifocal lenses (CooperVision)
4. Single vision distance lenses (modified monovision)
|Intermediate||1. PureVision Multi-Focal (Bausch + Lomb)
2. Any aspheric multifocal
|1. PureVision Multi-Focal (Bausch + Lomb)|
2. Any aspheric multifocal
|Near||1. PureVision Multi-Focal (Bausch + Lomb)
2. Frequency 55/Proclear Multifocal (CooperVision)
|1. Two “N” Proclear Multifocal lenses (CooperVision)|
2. GP multifocals
3. Frequency 55/Proclear Multifocal (CooperVision)
4. Air Optix Aqua Multifocal (High Add) (Alcon)
5. SynergEyes Multifocal/Duette (SynergEyes)
|Toric||1. Proclear Multifocal Toric (CooperVision)
2. Custom designs
4. Modified monovision
|1. GP multifocals|
2. Custom designs
3. SynergEyes Multifocal/Duette (SynergEyes)
|Hom-Gallagher-Eiden GP Multifocal Grid|
|Bias||Low: +1.00D to +1.50D Spectacle Adds||High: +1.75D to +2.50D Spectacle Adds|
|Distance||Anterior aspheric Concentric||Translating|
|Intermediate||Anterior aspheric Posterior aspheric||Posterior aspheric|
|Near||Posterior aspheric Combination||Translating|
|Toric||Add back toric to design Add front toric if anterior aspheric||Add back toric to design*|
It is evident that multifocal contact lenses have improved greatly over the past few years, and this trend will continue in the years ahead (See “The Future of Multifocal Contact Lens Fitting” on p. 32). The forthcoming availability of daily disposable multifocals, more planned replacement toric multifocals in silicone hydrogel materials, hyperpermeable hybrid designs, multifocal designs in highindex GP materials, corneo-scleral multifocal GP lens designs, and post-refractive surgery GP multifocals makes the future especially exciting.
It is also evident that we all need to be very proactive in educating consumers about this option. Multifocal contact lenses should be offered to every single contact lens wearer who has become presbyopic and should represent the primary option for these individuals. As multifocal contact lens wearers, we want our patients to enjoy the visual freedom and quality of vision at all distances that we enjoy. Your patients deserve this opportunity, and building your presbyopic contact lens practice will result in enthusiastic patients, tremendous personal satisfaction, and practice growth. CLS
Bruce Anderson, OD; Doug Benoit, OD; Jill Beyer, OD; Jean Blanchard; Ray Brill, OD; Steve Byrnes, OD; Rob Davis, OD; Greg DeNaeyer, OD; Scott Edmonds, OD; Tim Edrington, OD, MS; Art Epstein, OD; Dave Fancher; Leslie Gallagher, OD; Milton Hom, OD; Jason Jedlicka, OD; Mike Johnson; Pat Keech, OD; Mike Lipson, OD; Derek Louie, OD; Bob Maynard, OD; Craig Norman, FCLSA; Neil Pence, OD; Roxanna Potter, OD; Tom Quinn, OD, MS; Phyllis Rakow, FCLSA; Susan Resnick, OD; Kevin Roe, OD; Kevin Sanford; Harvard Sylvan, OD; Loretta Szczotka-Flynn, OD, PhD; Jeff Walline, OD, PhD; Frank Weinstock, MD; Rick Weisbarth, OD; and Eric White, OD.
To obtain references for this article, please visit http://www.clspectrum.com/references.asp and click on document #195.
|The Future of Multifocal Contact Lenses|
|I feel that both GP and soft multifocal contact lens options have dramatically improved over the past five years. What we really need is more public education both from industry and from eyecare practitioners. Most patients do not understand presbyopia and the available contact lens options.|
|— Tim Edrington, OD, MS, FAAO|
|The contact lens multifocal market will continue to grow in 2012. The future is bright given that presbyopes are projected to be the single largest group of potential contact lens wearers by 2018 (Studebaker, 2009). This makes fitting the newer-technology multifocal contact lenses a smart way for practitioners to get ahead of their competition and grow their practices, especially since these lenses have many benefits over monovision.|
|— Rick Weisbarth, OD, FAAO|
|As all of the major contact lens manufacturers now have multifocals available in silicone hydrogel materials and all have improved their MF designs, materials, and/or fitting guidelines, we should see a noticeable increase in multifocal fittings this year. Perhaps more importantly, the use of technology—in particular topographers and aberrometers—will provide practitioners with information that can determine whether a particular design is likely to be successful. That will save valuable chair time as well as increase the success rate. Also, I will not be surprised if we see one-day multifocals on the market in 2012, and that should provide an additional boost to the number of multifocal fittings.|
|— Harvard Sylvan, OD|
|Soft multifocals work well for some patients, but nothing compares to GP lens optics. I do not see the market expanding for the corneal GP market, but I do see the scleral lens designs—from corneo-scleral to scleral lenses—becoming a platform for presbyopic designs.|
|— Steve Byrnes, OD, FAAO|
|Dr. Bennett is an associate professor of optometry at the University of Missouri-St. Louis and executive director of the GP Lens Institute. You can reach him at email@example.com.|
|Dr. Henry is currently a clinical professor and director of Clinical Operations and Residencies at the University of Missouri-St. Louis, College of Optometry. Currently she serves as the chair of the Association of Contact Lens Educators (AOCLE).|