Abstract
Purpose: :
From years 2006 to 2010, a total of 93358 patients purchased 2 week (2w) contact lenses from our clinic. From 2006 to 2009, the number of patients purchasing 2w lens decreased by average of 3.2 percent annually, a 9.3 percent decrease in total. We investigated the reason of this reduction by statistical evaluation and patient interview.
Methods: :
Patients whom purchased 2w contact lenses at our clinic from years 2006 to 2009 but did not buy 2w lenses in 2010 were defined as the "2w withdrawal group". The 2w withdrawal group was sorted into two groups, patients who purchased non-2w lenses in 2010 (= "switching group") and patients who did not buy any lenses in 2010 (= "lost group"). Next, interview was made to 165 patients, randomly chosen from patients of the switching group. Patients were asked to answer freely why they have stopped using 2w lenses.
Results: :
Out of 87736 patients, 43515 were considered as the 2w withdrawal group. The 2w withdrawal group was composed of 8217 switching group patients and 38298 lost group patients. The switching group patients switched to 1 day lens (7758 patients) > conventional soft lens (258) > rigid gas permeable lens (159) > 1 month lens (129) > 1 week lens (40), duplication allowed. In patients purchasing both 2w and 1 day lens (approximately 4000 to 6000 patients per month), the average ratio of 2w lens purchase to 1day lens purchase decreased from 68.56 % (January 2006) to 41.22 % (July 2010). From patient interviews, the main reason of 2w purchase arrestment was a changeover to 1 day lens (120/165), which was because of "pollen allergy or other eye disease (50/120)", "troublesome lens care (48/120)", and "1 day being more hygienic (30/120)" (duplicates allowed).
Conclusions: :
In patients who are continuing to purchase contact lenses from our clinic, the main reason of the decrease in the number of patients purchasing 2w lens was a shift to 1 day lens. This shift was supposedly because of allergy or other eye diseases, troublesome lens care, and health concern. Since these causes are difficult to exclude, it can be presumed that the shift from 2w to 1 day lens will continue on in the near future.