Try the Matrix When Fitting
Soft Spherical Contact Lenses
BY DAVID J. KAIRYS, OD, MS
Contemporary soft contact lens fitting for simple myopic and hyperopic patients typically involves choosing from an array of major brands of spherical contact lenses, then tailoring replacement and wearing schedules to suit the individual
patients. Some contact lens brands provide fitters with a variety of base curves (usually steep, medium and flat, such as Bausch & Lomb's Optima series), but some employ only one base curve and diameter (CIBA Vision's FreshLook lenses) that will fit most contact lens candidates.
Each major contact lens brand possesses particular material characteristics and design parameters such as water content, ionic character and edge contour. Manufacturers market their products as those that are most likely to satisfy patients. Major contact lens brand manufacturers also liberally provide their product lines to eyecare practitioners as free diagnostic lenses. Even nonlicensed paraprofessional contact lens fitters have received numerous banks of free fitting lenses, as contact lens manufacturers attempt to grab more market share in this highly competitive environment.
1 Contemporary Soft Lens Fitting Facts
1. Major spherical soft contact lens brands are similar in terms of their
2. You cannot predict how subtle differences that exist among major brands will affect individual patients -- empiric fitting is necessary
3. Involved patients are more successful than passive patients --
partnering with patients rather than unilaterally prescribing results in
better patient satisfaction
Common Lens Fitting Practices
I have found that the relative success of most patients depends less on selecting specific contact lens parameters than on selecting and training patients. Indeed, few differences appear to exist among contact lens brands that practitioners can scientifically identify as corresponding to a patient's specific ocular traits. This relative interchangeability has even resulted in mail-order providers illegally substituting in-stock or lower-priced contact lenses for out-of-stock lenses.
Many contact lens fitters employ a purely arbitrary, and usually unilateral, approach to selecting contact lenses for patients. They often base lens fitting on what is readily available, what is cheapest to purchase, what offers the best after-market rebate or even what the fitter habitually pulls off the shelf. By far the worst fitting method within the contact lens "trenches" involves some corporate optometry directives that advocate "sale-of-the-week" contact lens brands. This practice seems at odds with the historical precept that, as physicians, eyecare practitioners hold patient benefits above mercantile concerns.
Table 1 summarizes the facts I have learned through my experiences in fitting contemporary soft contact lenses.
Professional Experience Yields a New Method
Former J.A.O.A. editor Dr. John Potter once said that the primary determinant in a contact lens patient's success must be the fitter's skill, but this hasn't been my own experience. Time and again I've found that patient selection and training determine success. I've also found that I can't reliably predict which contact lens will best serve a given patient. In fact, many patients who have long histories of contact lens wear in other practices have related to me that they've tried one lens brand for a year, but they prefer a different lens brand (one they tried the previous year). Patient comments such as these can effectively guide a fitting session.
Finally, Geisinger Medical Center cardiothoracic surgeon Dr. Tarazewski once said, "Patients who are actively involved in their health care consistently experience better outcomes than uninvolved, passive patients." I have found that this important principle especially applies to good contact lens fitting. By offering several different (but essentially similar) lens brands and soliciting feedback from wearers, I simultaneously made my patients better, fuller partners in their contact lens care and engaged in a more intellectually honest and rational approach to empiric fitting. I call this fitting method the Contact Lens Matrix (Table 2).
What is the Matrix?
The Contact Lens Matrix approach represents my best effort to cost-effectively help my patients track their experiences with several similar contact lens types/brands. It helps me create truly cooperative doctor/patient relationships, which result in enhanced success and satisfaction. Having an active role in their eye care in turn encourages patients to comply with other aspects of their ocular health such as caring for their contact lenses, maintaining good hygiene practices, following their lens replacement schedules and attending follow-up exams.
If you want to try this fitting approach in your practice, an easy way to encourage patients to adopt it is to offer them a few "scenarios" of how they can apply the Contact Lens Matrix to their lens fitting experience.
For example, I typically say something along the lines of, "You might like the crispness of your vision with Brand A contact lenses and rate that a 10, but those lenses may tear easily and score only a one or two overall. Or you might like the comfortable feeling of Brand B, especially toward the end of your wearing day, but it just doesn't provide the clarity you need while driving home from work at night." Experiencing different contact lenses will help them choose the lens brand that best meets their needs.
The Contact Lens Fitting Matrix has proven a great asset to my practice. Following are some of the advantages you can gain from employing this method:
- It's a cost-effective means to determine which contact lens brand will be most acceptable to your patients
- It builds cooperation and encourages open communication between eyecare practitioners and empowered patients
- It cements patients to your practice because they have engaged in an active pursuit of their ideal lens
- It improves compliance with other health-related components of eye care, such as good hygiene habits and regular follow up.
To receive references via fax, call (800) 239-4684 and request document #101. (Have a fax number ready.)
Dr. Kairys practices in DuBois, PA, and has taught microbiology and biochemistry at Penn State
Contact Lens Spectrum, Issue: January 2004