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Validating Clinical Beliefs

A Disposable Lens Comparison

BY DARWIN L. MORMON, OD
JUNE 1998

Since their introduction in 1988, disposable lenses have steadily gained practitioner and patient acceptance, as well as a growing share of the contact lens market. Disposable lenses are safer and m more convenient and for most patients, they are more cost-effective than more convenient, and for most patients, are more cost-effective than conventional lenses. Despite these benefits, disposable lenses are available in a limited variety of parameters compared to conventional lens designs. While conventional lenses remain the best choice for patients who fall outside of the normal distribution of corneal diameter or curvature, disposable lenses reduce fitting complexity and overall chair time in average patients. Since average patients represent most of the patients we see, disposables have become a workhorse lens in most offices. However, some disposable lenses seem to intrinsically fit better and more universally than others, and finding the right disposable lens for each patient can still be a formidable task.

The Ideal Disposable Lens

An ideal disposable lens should fit the largest number of patients with the least amount of complication. It should also fit most patients on the first try. While conventional lenses are often trial fitted and then ordered in the correct prescription, the majority of disposable lens patients expect to leave with their lenses that same day. In order to accommodate these patients, it has become standard practice to stock a complete disposable lens trial fitting set with every parameter available for immediate dispensing. I recommend that you find the best and most universal lens for your patients and rely on this lens as your primary disposable option. If this lens fits the majority of patients, it can eliminate any need for multiple disposable lens fitting sets and large inventories.

Ultimately, it's the patient who decides if a contact lens performs adequately. However, most patients who experience discomfort or other problems have no idea that the lens or the fit is to blame. They assume that contact lens wear is uncomfortable, which is yet another reason to try to find the best fitting and most comfortable lens for your patients.

The Study Idea

Shortly after the introduction of the Biomedics55 disposable lens from Ocular Sciences-American Hydron, Inc., I became so convinced of its superiority that I began to refit almost every patient who came in to my office wearing another lens brand. I was able to fit patients more easily and with fewer problems than ever before, and it seemed that the majority of my patients preferred the Biomedics55 over their habitual lenses. The lenses seemed to fit beautifully and looked as good at follow-up exams as they did at the initial fitting visit. Although not perfect for every patient, the Biomedics55 fit more patients than any other disposable lens I had ever prescribed.

My success with the Biomedics55 lens prompted me to evaluate relative patient preferences of the lens compared to all other disposable lenses in my practice. I wanted to validate my clinical impressions and prove the logic of my prescribing habits. The study was my own idea, and I received no support or remuneration from the manufacturer.

The approach I used was simple. I asked 289 consecutive patients whom I refitted with the Biomedics55 lenses what they thought after they wore them for two weeks. All patients completed a questionnaire, where they indicated their preference between their habitual contact lenses and the Biomedics55 contact lenses according to lens handling, comfort, visual acuity and overall lens preference. Then I analyzed the accumulated data. Table 1 lists the demographic characteristics of the 289 patients I have evaluated thus far.

The Results

Of the 289 patients, 248 (or nearly 86%) preferred Biomedics55 to their habitual lenses. Table 2 shows the demographic breakdown of this population.

As shown in Figure 1, 89 percent of all patients who preferred Biomedics55 over their habitual lenses felt that they handled better, 42 percent felt that acuity was significantly improved, and 60 percent felt that Biomedics55 lenses were more comfortable.

Explore Your Research Potential

The results of this study confirm my impression that the Biomedics55 lens is preferred by the majority of my patients. I now know that the lens that I think performs best is also the lens that will be accepted by most of my patients. This will reduce chair time and allow me to reduce my stock of other brands and maximize my inventory of the lens that I know I will use the most. I can now deliver lenses from stock to the majority of my disposable lens patients. Close to 70 percent of my practice is dedicated to contact lenses, so this alone has created substantial cost savings and has made my practice more efficient and profitable than ever before.

To most patients, their doctor's skill is reflected in how well their lenses fit and perform. When I fit a new patient with a disposable contact lens, I now know with reasonable certainty what he will think of the lens and of my fitting skills. I also know that most patients wearing other contact lens brands will readily adopt the Biomedics55 lenses and will appreciate my decision to refit them.

Perhaps you should consider validating your own clinical beliefs with a simple patient preference survey. Studies like the one I conducted are simple to perform and give patients a sense of confidence in you and your desire to fit them with the best contact lens. With today's managed care environment and the need to keep things simple and efficient, every little advantage helps.