Monovision is a time-honored approach to managing presbyopia in contact lens wearers, but it’s a last resort in our practice. Whenever possible, I prefer to fit presbyopic patients in multifocal lenses, especially if I can get them into multifocals early, so they can start adapting to simultaneous vision while they still have residual accommodation.
Many practitioners view multifocal lenses as hard to fit or difficult for patients to succeed with, but that bias may be largely attributed to first-generation multifocal lenses. Second- and third-generation multifocal contact lenses are available in better materials and designs than ever before. In fact, each of the lens manufacturers has a newer lens that is better than its original offering in this category.
In general, I prefer silicone hydrogel lenses, for both health and comfort reasons. Studies have shown that hydrogel contact lens wearers report a less positive wearing experience and increasing difficulty with lens wear over time vs. silicone hydrogel wearers.1 Hydrogel lens wearers are also more likely to struggle in challenging environments, such as during dry or windy conditions, after napping or air travel.2
We all know that presbyopes face significant challenges in maintaining comfortable lens wear as they age, so it’s best to set them up for success on the comfort front as you’re helping them adjust to their declining accommodative ability.
Several different presbyopic lens designs are available, and practitioners who want to fit these lenses successfully should understand how each of them works. The following are the multifocal lenses that I rely on most frequently:
• Acuvue Oasys for Presbyopia (Vistakon) is a two-week replacement, center-distance lens that provides sharp distance and near in a comfortable material (senofilcon A) that is ideal for emerging presbyopes. The zonal aspheric optics combine elements of both the ring/zone and aspheric progressive designs. It’s the lens that Barry R. Basden, O.D., a private practitioner at Florence Eye Center in northwestern Alabama chooses himself. “Compared to a traditional ring design such as the Acuvue Bifocal, the newer-generation Acuvue Oasys for Presbyopia offers much more consistent vision across the zones,” says Dr. Basden.“That means that patients with larger pupils or those who are trying to see in dim light don’t have nearly as many unwanted visual symptoms as they did with the traditional designs.”
• The the Air Optix Aqua Multifocal (CIBA Vision) is another comfortable silicone-hydrogel option. It is a center-near aspheric design and the latest entrant into the multifocal market. It is made of lotrafilcon B, a silicone hydrogel material, and recommended for monthly replacement. “I’ve had good success with this lens, but I do find that it has a tendency to push more plus,” Dr. Basden notes. When a patient wearing this lens is struggling with distance vision, he recommends adding plus power, rather than the minus power one might expect.
• The PureVision Multifocal lens (Bausch + Lomb) is another aspheric center-near design, also in a silicone hydrogel material, balafilcon A, and intended for monthly replacement. Unlike the other two silicone hydrogel lenses, however, it is only available in two add powers (low and high), which can occasionally present problems for the patient who really needs a mid-range add.
• The Proclear Multifocal lens (CooperVision) like its predecessor, the Frequency 55, takes a unique approach. The spherical central portion of the lens targets either distance or near, with an aspheric progressive periphery. The patient wears an “N” lens in the non-dominant eye and a “D” lens in the dominant eye. Rather than low/mid/high, it comes in specific add powers from +1.00D to +2.50D, and is available in toric parameters, as well. “It can be a little tricky to find the right combination of lenses with this style,” Dr. Basden notes. But, it is an option worth considering for patients with astigmatism or those who require higher adds.
• SynergEyes hybrid bifocal (SynergEyes, Inc.) is another lens we both like as a trouble-shooting option. It’s also a center-near design, but the central portion of the lens is made from a rigid gas-permeable material, with a hydrogel “skirt.” It’s a great option for patients who have more than 2.00D of astigmatism. “I try this lens with patients who don’t see as crisply as they like with the other options,” says Dr. Basden. “We don’t have a lot of comfort problems with this lens. It feels like a soft lens with rigid lens optics.” However, it is more expensive than other multifocal lens options, and it doesn’t offer the oxygen transmission of a silicone hydrogel lens.
The first step in successful presbyopic fitting is setting appropriate expectations. A patient who expects to see 20/15 at distance and read the Wall Street Journal stock listings all day is not going to be happy with multifocal lenses. Dr. Basden agrees: “Failure with multifocal contact lenses is more often a communications failure, not a technology problem,” he says.
I tell patients that multifocal contact lenses will satisfy about 90% of their visual needs. And, I am careful to explain how simultaneous vision works and why I prefer it over monovision. Additionally, many patients don’t understand the progressive nature of presbyopia, so you really have to spend some time explaining what is happening to their vision—ideally, before it happens. If you have those conversations early, the chance of success with multifocal lenses goes up significantly.
“I’ve tried monovision and just about every multifocal lens on the market on my own eyes,” says Dr. Basden. “I think that really helps me explain the pros and cons of different approaches to patients—and it helps me set expectations, because I can tell them exactly what I’ve experienced.” At age 45, he wears a low add in both eyes. “With electronic records, I’m seeing patients and using the computer all day long. I can do anything I want wearing multifocal contact lenses. My distance vision is not as sharp as it is in spectacles, but I really don’t want to wear glasses, so that’s an acceptable tradeoff for me,” he tells patients.
|SOS: It’s not working!
|Here are some troubleshooting strategies when a multifocal fit doesn’t seem to be working:
• If you have made more than a 0.25D to 0.50D change in the lens power, something is wrong. Perhaps your refraction wasn’t accurate the first time. Start over with a good binocular refraction and eye dominance testing.
• Consider a single-vision distance lens in the dominant eye and a multifocal in the non-dominant eye. This is a good strategy for heavy computer users who are really dependent on intermediate vision.
• Consider part-time wear. In some cases, erring low on the add allows the patient to function well during most tasks. I will usually recommend that when patients need a stronger add for prolonged near work, they wear a pair of reading glasses over the lenses or progressive spectacles. Multifocal contact lenses don’t have to be the patient’s only option for visual correction.
• Go back to your fitting guide and follow the recommendations, step by step.
Start with good measurements. It’s imperative to use the right data in selecting lens pairs. Do a binocular refraction and push plus to make sure you aren’t over-minusing the patient. Identifying true ocular dominance at the start also contributes to a successful fit, especially when you need to make minor adjustments at the second or later visits. With the patient looking through his best distance vision in both eyes, I put a +1.50D lens over one eye at a time (some people use a +1.00D lens). If there is no change in binocular distance acuity with the lens over the left eye, then the right eye is the dominant one.
Use the fitting guides. Manufacturer-provided fitting guides increase your chance of success and can significantly reduce chair time. I have fit thousands of multifocals, but I still start with the fitting guide recommendation, in most cases. “It gives you a starting point and some idea of what to do next if the patient isn’t happy,” agrees Dr. Basden. “Just recently, I was having trouble fitting a patient. I had put a mid add Acuvue Oasys for Presbyopia lens in both eyes, and it just wasn’t working. When I went back to the fitting guide, it specified a low add in one eye and a mid in the other. That combination turned out to be perfect,” he says.
The lens selector tool for Acuvue Oasys for Presbyopia is one of the best available, in terms of ease-of-use and accuracy. It was validated in clinical trials involving 890 patients. Researchers said the lens selector tool enabled them to more than double the first-fit success rate, from 24% to 58%, and achieve a 74% success rate with a one follow-up visit.3 “By the second visit, we usually have the right lens pair,” says Dr. Basden. “But sometimes patients need a third try just to ‘prove’ to them that they really did have the best combination.”
Ask questions. Asking about patients’ daily visual demands—Do they drive at night? Use a computer all day? Do needlepoint?—can help you tailor lens options and powers to their specific needs. “For example, I like both the Acuvue Oasys for Presbyopia and the Air Optix Multifocal,” says Dr. Basden. “But what I have noticed is that, in the exact same prescription, the Acuvue Oasys lens provides sharper distance vision, so if the patient drives a lot, I might choose that one; if she has a strong preference for near tasks, I might opt for Air Optix.”
Make changes cautiously. If you can’t improve lines of vision, don’t make the change. And, unless the lens is clearly wrong, don’t make a change until the patient has worn the lens for a week and has had a chance to adapt.
Stick with the sweet spot. Even as presbyopia advances, I think the medium addition powers remain the sweet spot. They don’t overplus the patient and aren’t too detrimental to distance vision. For many patients, I would rather undercorrect the add as they age and add a little plus to the non-dominant eye.
To be successful with presbyopic lenses, you have to be willing to work with all the brands and to change brands for a given patient when necessary. It is definitely worth the effort. “Our patients who are successfully fit with multifocal contact lenses are incredibly loyal,” says Dr. Basden. I agree! The rewards for our patients and our practices are too great to eliminate this group of patients as contact lens candidates or consign them all to the loss of binocular vision. Considering today’s range of multifocal options, presbyopic fittings present a huge opportunity for eye care practitioners and patients alike.
1. Chalmers RL, Hunt C, Hickson, et al. Struggle with hydrogel CL wear increases with age in young adults. Cont Lens Ant Eye. 2009;32(3):113-9.
2. 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;84(4):302-8.
3. Coffee A, Young, Young G, et al. Multi-center evaluation of a silicone hydrogel (senofilcon A) multifocal soft contact lens. Poster. American Academy of Optometry. 2009.
Dr. Davis is in private practice in Pembroke Pines, Fla., and serves as an Adjunct Clinical Professor at Nova Southeastern University College of Optometry and Salus University. He is on Vistakon’s Professional Advisory Council and Essilor’s Advisory Board. Contact him at [email protected] or (954) 432-7711.