The Usability of Eye Drop Containers by the Elderly

Abstract

Difficulty using eye drop containers is a factor affecting treatment adherence among the elderly. However, although considerable attention has been given to investigating the effects of eye drop medications, less attention has been paid to usability of the eye drop containers. Therefore, in this study, we interviewed elderly patients who use eye drops for treatment purposes about difficulties they experience in physically self-applying the eye drops and the usability of eye drop containers, and then used the text-mining method to extract the factors they mentioned concerning the usability of eye drop containers. Eight factors were extracted concerning usability of the eye drop containers: ease of opening the cap; “hardness-softness” of the container; size of the container; shape of the container (“flat” or “curved”); ease of removing the plastic film from the container; one squeeze/action produces one drop; appropriateness of the amount of each drop; and the time between the squeeze and the drop reaching the eye. More subjects who were over 75 years of age mentioned softness of the containers. This result suggests that containers which deliver only one drop at steady velocity after each squeeze are desirable.