contact lens

Maximize Your Toric Lens Fitting Sets

Balance your selection of trial lenses to make fitting astigmatic patients fast and simple.

Cristina M. Schnider, O.D., M.SC. M.B.A., F.A.A.O. Jacksonville, Fla.

ILLUSTRATION BY RALPH VOLTZ

For many clinicians, fitting toric soft lenses has moved from the realm of “specialty” fitting into “everyday” fitting, mainly because advances in lens designs, materials and modalities have resulted in reduced chair times and more satisfied patients. In fact, according to Angel Alvarez, CEO of ABB Concise, Coral Springs, Fla., a leading contact lens distributor, the toric soft lens category was among the fastest-growing contact lens categories in 2011, with nearly double the growth rate of spherical lenses. In addition, a recent study revealed that roughly one-third of potential contact lens wearers require astigmatic correction.¹ So, we know a significant opportunity exists for toric soft lens correction.

The downside to all this good news: Any practitioner who is wholeheartedly behind the toric trend has had the challenge of having enough — but not too many — trial lenses with the appropriate parameters to accommodate most patients. Let's take a look at the numbers and how some practitioners are managing this inventory challenge.

What's in a trial set and why?

About 20 different brands of toric soft lenses are available in the United States, including daily disposable, two-week and monthly replacement modalities. If you were to stock just one trial lens of every parameter in every brand, your inventory room would overflow with more than 50,000 lenses. Not only is stocking that many trial lenses impractical, it's also unnecessary. Some statistics from ABB Concise help explain why.

The most commonly ordered toric soft lens prescriptions, regardless of brand, combine low sphere and low with-the-rule astigmatism. About 70% of orders require the low cylinder powers (0.75D and 1.25D) and six of the 18 axes (180°, 90°, 170°, 10°, 160° and 80°). Of all the possible sphere/cylinder/axis combinations (each one is a stock-keeping unit [SKU]), the top 250 SKUs account for nearly half of all toric prescriptions, and the top 1,000 will meet the needs of about 80% of patients. (See “Fig. 1,” right).

Fig. 1. The top 250 SKUs account for nearly half of all toric prescriptions, and the top 1,000 will meet the needs of about 80% of patients, according to statistics from ABB Concise.

The largest fitting sets for the major brands contain 1,100 to 1,200 diagnostic lenses. This may be only 20% to 40% of all available SKUs, but based on ordering statistics, these SKUs represent enough parameters to fit roughly 90% of patients. By narrowing the number of trial lenses in each set to the most commonly prescribed parameters, manufacturers can help you avoid having to manage an inventory of thousands of lenses, most of them rarely used.

Personalize your inventory

Although each toric lens fitting set should provide enough parameters to fit most of your patients most of the time, you may want to adjust the number of lenses in a set to meet your specific needs.

For example, Thomas Bobst, O.D., North Olmsted, Ohio, orders extra SKUs of the lenses he uses most often and maintains just a minimal fitting set for the others.

“It's a smart strategy to free up space for the lenses you need most in your practice,” he says. “I'm willing to give up some real estate in my lens room for the convenience of having a broader selection of trial lenses for my go-to brands.”

He notes some manufacturers double up on the most common SKUs in their fitting sets, so that a practice is less likely to run out of these lenses before more can be ordered.

“If I have enough trial lenses to fit 80% of my astigmatic patients and I have to order trial lenses for the other 20%, that's a comfortable range,” Dr. Bobst says.

You can be confident that the parameters provided in each brand's fitting set will meet most of your patients' needs, but how do you decide which sets to maintain? In general, you may want to consider having two different designs (e.g., blink-stabilized and prism-ballasted), two materials (hydrogel and silicone hydrogel) and a daily disposable. In the end, your personal preferences guide your decisions.

Performance first

Mitch Cassel, O.D., is president of Studio Optix in Manhattan, where real estate is at a premium and inventory management is a priority. For him, lens performance is the deciding factor when choosing which trial sets to stock.

“As a contact lens specialist, I want to have as many opportunities as possible to maximize comfort and vision for my patients,” he says. “I'd like to carry every fitting set, but I have to consider space. So my first consideration is performance. If a lens is effective for my patients and it's one that I use often, I need those trial lenses in the office.”

After that, Dr. Cassel says he is most likely to make room for new technology, especially in growing modalities, such as toric lenses and daily disposables.

“If a patient comes in every year and I prescribe the same lens, he may not perceive much value in my recommendations. I want patients to know my practice is on the cutting edge with the latest, most advanced technology,” Dr. Cassel says.

At any given time, Dr. Cassel says he has four or five toric soft lens fitting sets in his practice.

“Whenever I consider a new lens, I also have to think about what [lens] I might want to retire. If a new lens can provide better comfort or has more parameters, then I will replace a lens that is less comfortable or less convenient …” he explains.

Dr. Bobst, who currently has six toric fitting sets, says he also gives top priority to lens performance.

“I may also complement my stock of preferred lenses with lenses in a different material or design for patients for whom my first choice isn't a good match. I also may stock a fitting set for an older, less expensive brand,” he says. “Even if I don't personally use those lenses, I want to be able to accommodate new patients who may be wearing them. I try to convert those patients to what I consider better options, but there will always be some who want to continue with what they have.”

Restocking rules

Starting with a balanced selection of trial lenses is important. Making sure your go-to lenses are always in stock is another challenge.

In a recent market study involving 150 practices, ABB Concise found an average out-of-stock rate of 20% for toric soft lenses. In other words, one in five SKUs in the original trial set were missing at the time of the study.

“That means something in the process has broken down, and those lenses aren't being restocked,” Mr. Alvarez says. “If they aren't restocked, they aren't available to fit.” (See “When the Inevitable Happens,” page 46.)

Regardless of the method you use to manage your inventory, the key to success is to be consistent in using it.

In Dr. Bobst's practice, for example, whenever a staff member pulls a diagnostic lens, he has her write the SKU number on a notepad, which serves as a reference for the practice's weekly lens replacement order.

In Dr. Cassel's practice, he says hand-held scanners are used to track inventory.

“Keep in mind that your distributors' or manufacturers' representatives can be valuable business partners in helping you regularly restock your trial lens sets,” Dr. Cassel says. “Those relationships should be an important component of your inventory management strategy.”

As Dr. Bobst notes, “…The worst thing that can happen is that you tell a patient you have a new lens in mind that is perfect for her because of attributes A, B and C, and then you don't have it in her prescription. It undermines your credibility.”

New era of toric lens ease

Thanks to advanced lens technology and robust trial sets, there is little risk in fitting toric soft lenses, especially for O.D.s who carefully choose their fitting sets and implement a process for regularly restocking them.

As Mr. Alvarez notes: “Fitting sets, which represent a huge investment by manufacturers, have been designed to help set up practitioners and their patients for success.” OM

Mr. Alvarez is CEO of ABB Concise, headquartered in Coral Springs, Fla. In addition to his private practice in New York, Dr. Cassel is the owner of Custom Color Contacts, providing soft lens designs for prosthetic, cosmetic and special eye effects for over 20 years to eyecare professionals and the motion picture and television industries. He is a consultant, lecturer and investigator for several contact lens companies, including Vistakon, CooperVision, and Alcon (CIBA Vision). Dr. Bobst is a consultant to Alcon (CIBA Vision), Bausch + Lomb and Vistakon.

1. Young G, Sulley A, Hunt C. Prevalence of astigmatism in relation to soft contact lens fitting. Eye Contact Lens 2011 Jan;37(1):20-5.

Dr. Schnider is senior director of Professional Communications for Vistakon. Send comments on this article to optometricmanagement@gmail.com.