Abstract
Purpose:
In Japan, there have been few studies longitudinally analyze and compare the prescription of single vision and multifocal lenses. Therefore, an 8 year large-scale epidemiological study on the change in the number of prescriptions of the single vision and the multifocal contact lenses was carried out on approximately 180,000 eyes of Japanese subjects aged 40 years or older; and 1,220,000 boxes of contact lenses which were prescribed during this period.
Methods:
The subjects of this research were the 184,397 eyes of men and women in the age 40-96 age range who had a medical examination for a prescription of contact lenses at Okada Eye Clinic in Yokohama, Japan; and 1,187,375 boxes of single vision contact lenses (96.7%) and 40,965 boxes of multifocal (3.3%) contact lenses: 1,222,340 boxes in total, which were prescribed between January 2005 and December 2012.
Results:
By multiple regression analysis, the annual change in the number of single vision contact lenses prescribed was show to significantly increased in both sexes (β = 0.1981, p<0.0001 in men; 0.2173, p<0.0001 in women). On the other hand, the multifocal contact lenses had a tendency to decrease in both sexes (β = −0.0011, p=0.4590 in men; −0.0081, p<0.0001 in women). Furthermore, there was an analysis of the annual change in the number of various single vision contact lens types (1-day, 1-week, 2-week, 1-month, SCL, HCL) prescribed; and various multifocal contact lens types (1-day, 2-week, SCL, HCL) prescribed. Prescriptions of 1-day and 1-month contact lens types both significantly increased (p<0.0001) in the single vision contact lenses, but the number of multifocal contact lenses held steady or had a tendency to decrease; and there were no types of contact lens for which prescription clearly increased.
Conclusions:
Japan is an aging society; the demands for bifocal glasses are rising, and the prescriptions are increasing. However, the number of the perceptions of various multifocal lenses doesn’t change or even shows a tendency to decrease. This may be because the quality of vision of the multifocal contact lenses is not good as the bifocal glasses. It is suggested that the improvement of the quality of the multifocal contact lenses can be expected.
Keywords: 477 contact lens