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Making Multifocals Work

BY KEITH PARKER, NCLC

It's frustrating to hear practitioners say, "there still aren't any good bifocal contact lens designs." It just requires taking the time to assess the needs of patients and to educate them properly on what to expect.  Having a large variety of trial lenses is also helpful.

As a manufacturer of bifocal and multifocal contact lenses for over 20 years, I can sympathize with doctors' frustrations with the reproducibility of certain designs. But with current manufacturing and verification systems, we can now produce very consistent lenses over and over again. Which design is best? Just like in the spectacle world, there will never be one design to suit everyone's needs. The right modality must be selected for the patient's individual needs with consideration to physical limitations.

For the past four years, I've been very active in fitting and recommending multifocal lenses by conducting free trial fitting sessions for presbyopic patients in the offices of eyecare practitioners. To participate, patients must have a current paid examination from the doctor. There is no other obligation to the doctor or the patient unless the patient leaves the office with the lenses. I've seen over 1,400 patients in this type of setting.

My Fitting Protocol

After the doctor's staff pulls the files of all interested patients and weeds out the poor candidates, I end up seeing an average of 10 patients on the fitting day. I bring all the lenses needed, usually about 300 Unilens and Softsite lenses (Unilens Corp.), and as many rigid contact lenses as there are rigid lens patients (fit empirically, not just trial lenses). I always bring along a rigid lens trial set to accommodate walk-ins, as well as my modification unit in case I need to adjust some RGPs on the spot.

I handle the first couple of patients so practitioners can observe how I educate patients on what to expect from this new modality. After inserting the lenses, I answer patients' questions about the design, and I listen to their visual requirements and expectations. I inform them that this modality rarely yields the kind of crisp clear visual acuity that spectacles provide and that there will have to be some compromise on their part to be successful. I always tell them that the first lenses we try end up being the lenses used for the final fit only 40 percent of the time. I point out that they can see near vision above their head and that their peripheral vision is improved over spectacles.

To allow the lenses to settle before fine-tuning the fit, I ask patients to walk outside and then come back into the office and pick up a magazine. When they come back, I ask them what they like and don't like about the modality. Then I address the area of concern by performing overrefraction with small 0.25D handheld trial lenses. I occlude only if I am getting very poor acuity that doesn't improve. We all know that with an aspheric lens, a 0.25D change in power will sometimes yield two lines of improved acuity on the chart. That same 0.25D power change will usually be the difference between success and failure.

Fear of Commitment?

Multifocal failure is not a function of a lack of designs, but of a lack of commitment by practitioners to understand the designs and to invest in the resources, including acquiring fitting sets and taking the time to properly educate patients. Will multifocal contact lenses ever be as good as spectacles? In most cases, no, but consider the advantages: better peripheral vision, better depth perception and freedom from eyeglasses for most of the patient's day-to-day activities.

Practitioners who tell their patients that they are waiting for a design that works before they try multifocals run a great risk of losing patients to a competitor who is willing to try.

Keith Parker is the general manager for Essilor Laboratories of America, Contact Lens Division. He has specialized in the manufacture of custom rigid contact lenses for 22 years.