MULTIFOCAL CONTACT LENSES
Getting to Know the New "Kid" on the Block
The Air Optix Aqua Multifocal can play an important role in building your practice and increasing patient satisfaction.
By Thomas G. Quinn, OD, MS, FAAO
Remember when you were a child and someone new moved into the neighborhood? How did you react to the "new kid on the block"? If you're like most of us, you probably approached him with some initial caution, mixed with some hope for a new friend. Only after getting to know him did you bring him into the fold.
Well, there's a new kid in the contact lens neighborhood: the Air Optix Aqua Multifocal from CIBA Vision. Here's some information to help get you acquainted with the lens and the role it can play in your practice.
HOW DID I GET HERE?
When faced with the common scenario of having an emerging presbyope wearing contact lenses complain of near blur, what do you do? In the past, we'd push the plus a half-diopter or so in one eye to buy some time.
What about subsequent years? As the patient's presbyopia advances, we often continue the trend of pushing plus in the nondominant eye, right? Soon we find the patient is in full-blown monovision.
MONOVISION: THE GOOD AND THE BAD
The above scenario demonstrates one of the greatest strengths of monovision: it's easy to move into it. The truth is monovision may be easy in the early going, but as the disparity between the two eyes increases over time, issues start to emerge. Examples include complaints with night driving, depth perception ("I have trouble parking my car") and blur at the intermediate, such as when viewing a computer screen, a car's speedometer, or price listings for products on grocery store shelves. Now what?
Often, at this advanced stage in the process, we attempt to switch the patient to a multifocal lens as a "problem solver." Unfortunately, the patient's brain has been trained to live with monovision, so it may be difficult to reorient the patient to multifocal optics. This is particularly true with high add powers.
BE AN EARLY ADOPTER
The problems outlined above can be avoided if you put emerging presbyopes in multifocals from the get-go. Emerging presbyopes adapt to multifocal optics more easily than advanced presbyopes, and they're more easily transitioned into higher adds over time. What's more, when put head to head against monovision, multifocals are preferred by approximately 7 out of 10 patients.1-2
WHAT'S BEEN STOPPING US?
So, why hasn't the eyecare community fully embraced the multifocal-first approach? Simple: most multifocal designs don't deliver the distance vision desired by many patients.
A NEW DESIGN
Ciba Vision set out to develop a multifocal lens that would provide, first and foremost, quality distance vision. Enter the Air Optix Aqua Multifocal, which employs a 3-ADD system (LO, MED, HI), all of which transition from the center near zone to provide near, intermediate and distance vision for the full range of presbyopic patients (Figure 1).
Figure 1. Air Optix Aqua Multifocal 3-ADD System.
The Air Optix Aqua Multifocal is manufactured using lotrafilcon B, the same material used in the Air Optix Aqua single-vision lens. It's approved for up to 6 nights or 7 days of extended wear and should be replaced on a monthly basis.
LAYING THE FOUNDATION
To be successfully fit, all multifocal contact lenses must be derived from a detailed, current refraction. Take particular care to give the patient no more minus in the distance than what's actually required to provide clear distance vision. You'll understand why this is important when I discuss troubleshooting later in this article.
Once you have acquired an accurate refraction, determine the vertex-corrected, least minus/most plus, spherical equivalent power. This will be your initial distance power.
FINAL PIECE OF THE PUZZLE: THE ADD
The next important step is determining the optimal spectacle add for the patient. This should be done using a "least plus" approach: you won't need or want to overdo the near ADD with this lens; distance is the place to push the plus. Once distance power and spectacle add have been determined, use the fitting guide to choose which contact lens ADD to select for each eye (Figure 2).
Figure 2. After determining distance power and eye dominance, use the Initial Lens Selection Guide to select the contact lens ADD power for each eye.
I can't overstate the benefits of starting with what's suggested by the fitting guide. The guide has been developed based on research studies that have established the approach that works best with these lenses. Give yourself a head start by following the fitting guide. You'll maximize success and minimize chair time.
Once lenses are applied, allow them to settle for 5 to 10 minutes. Vision will improve as the fit stabilizes. While the lenses are settling, escort the patient to the reception area and instruct him to look out the window or pick up a magazine: in short, explore his visual world.
KEEP IT REAL!
When the patient returns to the examination lane, before jumping into testing, ask him "How ya' doin?" The response to this open-ended question will guide your next step. If the patient reports the vision is satisfactory at distance and near, don't change anything. If he has a visual complaint, for example, distance blur, you know this is where you need to focus your attention.
When assessing vision initially, start with the acuity chart, then ask the patient to look at his watch or cell phone. If he performs well with these tasks, you can rest assured he'll be able to perform common, day-to-day, near-oriented tasks without much difficulty.
When you check vision with the acuity chart, do so binocularly and with the room lights up to obtain a truer reflection of real-life performance.
Again, if distance and near vision are satisfactory, release the patient without making any changes to the lenses.
THREE TIPS FOR MULTIFOCAL SUCCESS
I find it helpful to share what I call "Three Tips for Multifocal Success" with my patients new to multifocal lenses. I find these tips help establish realistic expectations that lead to happier patients.
1. Light is your friend. The same studies that found multifocal lenses outperform monovision also shed light on the importance of good illumination for near tasks performed while wearing multifocal lenses.1-2 Proactively encourage your multifocal patients to use good lighting for detailed near tasks.
2. These lenses are designed to work together. Encourage patients to resist the temptation to continually compare vision between the two eyes. Keep them both open and see better!
3. Specialty lens fitting is a process. Employ the "no-surprise" approach to eye care by reminding patients that fitting specialty lenses is a process. Sometimes the first pair works, and sometimes adjustments are required to enhance vision. Informing and reassuring the patient at the outset avoids jeopardizing their confidence in you later if changes are necessary to achieve visual goals.
SOLVING DISTANCE VISION COMPLAINTS
Patients who return with vision complaints at distance, near or both, should be over-refracted with loose lenses under binocular conditions. Over-refract each eye individually, but again, under binocular conditions.
Although our first inclination with distance complaints may be to introduce minus, start by using plus power loose lenses in 0.25D steps. There is some evidence from refractive surgery centers that up to 40 percent of patients may be over-minused with their spectacles.3
If a patient reports improved distance vision with addition of plus to the distance power, it's a win-win. The patient will likely appreciate improvement in near vision, as well. Incorporate these changes in the distance power only, keeping the original ADD, and dispense the new lenses.
If plus power over either lens doesn't provide adequate distance vision, introduce minus lenses in 0.25D steps. Again, perform the over-refraction on each eye individually, under binocular conditions. If a minus power loose lens helps distance vision, always take the additional step of assessing the impact this has on near vision. Have the attitude of not giving the patient any more minus than what is absolutely necessary to solve his distance vision complaint. The less minus given means the less chance you'll adversely impact near vision.
If increasing minus distance power improves distance vision and near vision remains clear, simply dispense new lenses incorporating the new distance power without changing the ADD.
WHEN CHANGING DISTANCE POWER DOESN'T WORK
In cases where distance over-refraction doesn't improve distance vision, modify the ADD power according to the Enhanced Vision Guide.
It's interesting to note the Enhanced Vision Guide doesn't recommend using a single-vision lens on one eye to solve distance vision problems, a common strategy employed by other multifocal designs. This suggests a high level of confidence on the part of the manufacturer that distance vision can be satisfactorily obtained with some ADD version of the Air Optix Aqua Multifocal lens.
Note that the Enhanced Fitting Guide recommends reducing the ADD in one eye or the other to improve distance vision when an over-refraction doesn't help. In the +1.25D to +1.50D ADD group, it is recommended to lower the ADD in the dominant eye. Problem-solving strategies for the more advanced presbyope involve modifying the ADD in the nondominant eye.
SOLVING NEAR-VISION COMPLAINTS
When a patient reports unsatisfactory near vision, again begin by assessing distance power. Perform an overrefraction on each eye individually under binocular conditions using loose lenses in 0.25D steps. If the patient accepts more plus in the distance power, assess the impact on near vision. If the patient reports satisfactory vision, simply change the distance power but keep the ADD the same.
If near vision still isn't satisfactory, consult the Enhanced Vision Guide. Note that the first step is to assess the impact of increasing plus in the distance lens power of the dominant eye, using a handheld trial lens. If this doesn't solve the patient's near complaint, then and only then is it acceptable to modify the ADD.
WHY SO STINGY WITH THE ADD?
Note that for the high ADD powers, it's recommended that the ADD be reduced, rather than increased, on the nondominant eye to solve near vision complaints. The rationale is that it's assumed that the near complaints in these situations are related to the presence of aberrations rather than from lack of plus power. Lowering the ADD reduces these aberrations, thus improving visual performance.
NOT ANOTHER "ME TOO" LENS
The Air Optix Aqua Multifocal offers a unique design that's a welcome "new kid on the block." Now that you've gotten to know it, I encourage you to welcome it into your practice. You'll soon recognize you have a new friend.
|DR. QUINN IS IN GROUP PRACTICE IN ATHENS, OHIO. HE IS A DIPLOMATE OF THE CORNEA AND CONTACT LENS SECTION OF THE AMERICAN ACADEMY OF OPTOMETRY, AN ADVISOR TO THE GP LENS INSTITUTE AND AN AREA MANAGER FOR VISION SOURCE. HE HAS SERVED AS AN ADVISOR/CONSULTANT TO COOPERVISION, CIBA VISION AND VISTAKON AND HAS RECEIVED RESEARCH FUNDING FROM AMO, BAUSCH + LOMB, CIBA VISION, COOPERVISION AND VISTAKON.|
1. Situ P, Du Toit R, Fonn D, Simpson T. Successful monovision contact lens wearers refitted with bifocal contact lenses. Eye Contact Lens. 2003;29:181-184.
2. Richdale K, Mitchell GL, Zadnik K. Comparison of multifocal and monovision soft contact lens corrections in patients with low-astigmatic presbyopia. Optom Vis Sci. 2006;83:266-273.
3. Personal communication, October 3, 2009. Donald Faimon, OD, MidWest Eye Center, Cincinnati, OH.