The Cost of Lens Care Vs. Daily Disposable Contact Lenses

Kelly Mai-Le, OD and Patrick Caroline, FCLSA, FAAO
July 2001

This year marks the 30th anniversary of the introduction of soft contact lenses in the United States. Some may remember the steep, thick lens designs of 1971. Equally archaic was the modified baby bottle warmer disinfection system (Figure 1). Those humble beginnings ushered in an era of dramatic changes in materials, care products, wearing schedules and more recently, frequency of lens replacement.

It is hard to believe that daily disposable lenses have been available to practitioners for over six years. However, recent market data shows that in the United States only one out of 30 new soft lens patients is fit with daily disposable lenses. Why is this number so low, especially in light of the fact that most practitioners agree that daily disposable lenses are the healthiest choice for patients?

Figure 1. First soft lens disinfection system introduced in 1971

In the past, if you asked why we were not suggesting daily disposable lens for all of our appropriate patients, our answer would have been the high cost of these lenses. Recently we completed a study at Pacific University that forced us to totally rethink our attitude toward the cost of daily disposable lenses.

We calculated the cost of contemporary lens care by measuring the amount of solution used annually by patients. This was accomplished by performing 30 consecutive cycles of lens disinfection as outlined in the manufacturer package insert. The solution bottles were weighed prior to and after disinfection, and the amount of solution used was calculated. The cost for each product was based on its average price from five large retail stores in the Portland, Oregon area.

Costs of Lens Disinfection and Soft Lenses

	Figure 2a. Diffuse SPK secondary to a multi-purpose solution sensitivity.

Table 1 lists lens care products and the projected annual costs for the patient. Table 2 shows the average annual cost when the products were grouped by category as multi-purpose disinfection ($138 annually) and hydrogen peroxide disinfection ($315 annually). Table 3 lists the approximate annual cost to our patients for daily, two-week and one-month replacement lenses. Table 4 shows our patients' annual cost for two-week and one-month reusable lenses plus care solutions. When the total annual costs of two-week and one-month replacement lenses are compared to that of daily disposable lenses (about $360), the similarities are quite striking.

Daily Disposable Lens Benefits

By now, we are aware of the many advantages (ocular health, patient satisfaction and patient compliance) associated with wearing daily disposable lenses. For the past two years, this modality has been our first choice for all patients interested in soft lenses. Additionally, we strongly recommend daily disposable lenses for patients with seasonal allergies, part-time lens wearers, sports enthusiasts and travelers.

	Figure 2b. Multi-purpose solution induces conjunctival injection.

However, we believe the biggest advantage of daily disposable lenses is in the total elimination of lens care products, in particular multi-purpose chemical disinfection systems that have been shown to cause dry eye symptoms in many reusable lens wearers. Remember that solution sensitivities may occur at any time during a patient's contact lens-wearing history. The sensitivity may manifest as an acute, or more commonly, delayed reaction to the MPS. In an acute sensitivity, the clinical findings are obvious and occur shortly after the initial exposure to the solution. Patients experiencing an acute sensitivity will frequently complain of burning and stinging and manifest the clinical signs of a diffuse superficial punctate keratitis and conjunctival injection (Figures 2a and 2b).

Figure 3. Multi-purpose solution delayed onset non-keratitis.

A delayed reaction to a specific lens care product is significantly more common and more difficult to diagnose. With delayed sensitivities, the patient frequently reports a long history of relative success with his chemical disinfection solution, yet careful slit lamp examination often reveals no abnormal findings (Figure 3). We refer to this normal clinical presentation as a "non-keratitis." In our experience, successful diagnosis of the delayed onset solution sensitivity is initiated by the patient's single subjective symptom of ocular dryness.

Because the patient's complaints mimic those of a true dry eye syndrome, solution sensitivities are often misdiagnosed as keratoconjunctivitis sicca. Patients are told they have dry eyes, and they must reduce their wearing time and implement frequent artificial tears. It is clear that neither of these strategies adequately addresses the source of the problem which we believe (in many cases) to be a solution sensitivity. In our hands, daily disposable lenses or a preservative-free disinfection system have proven effective at addressing the dry eye complaints associated with modern chemical disinfection systems.

Table 1.

Every year approximately two million soft lens wearers discontinue their contact lenses. Studies show that over 50 percent of those patients cite discomfort (dryness, grittiness) as the major reason. We don't know how many of these patients are abandoning their lenses due to undiagnosed solution sensitivities, complications related to surface deposition or keratitis. Every study performed with daily disposable lenses has shown reduced ocular complications and dramatically improved patient satisfaction over reusable contact lenses. For these reasons, daily disposable lenses remain our number one choice for all appropriate patients. In the future, 30-day continuous wear silicone-hydrogel lenses may offer another excellent alternative for eliminating the complications associated with contact lens care solutions.

The authors acknowledge Steven Jung, OD, and Kenneth Williams, OD, for their assistance with the study.

Dr. Mai-Le is a graduate of the Illinois College of Optometry and is currently a contact lens resident at Pacific University. Patrick Caroline is an associate professor of optometry at Pacific University and an assistant professor of ophthalmology at the Oregon Health Sciences University.