Purpose
To determine the efficacy, safety, and efficiency of eye drop instillation by glaucoma and ocular hypertension (OHT) patients and to identify demographic and behavioral characteristics that impact efficacy of eye drop instillation.
Methods
Subjects (n=117) with open-angle glaucoma or OHT who had at least 6 months of experience with self-instillation of ocular hypotensive eye drops were video recorded while self-instilling artificial tears. All subjects completed the Rapid Estimates of Adult Literacy in Medicine Questionnaire (REALM), the Glaucoma Specific Beliefs about Medicine Questionnaire (BMQ), and a mini mental status examination (MMSE). A single masked observer graded video recordings of eye drop instillation. Efficacy was assessed based on whether the subject successfully instilled at least one eye drop on the ocular surface, and was graded in a binary fashion. Safety was assessed based on whether the bottle tip made contact with the ocular surface or periocular skin, and was graded in a binary fashion. Efficiency was graded as the number of drops expelled. Associations between behavioral and demographic characteristics and the likelihood of successful eye drop instillation were explored using t-tests for continuous variables and chi-square for categorical variables.
Results
87.8% and 90.4% of subjects successfully instilled at least one eye drop on the ocular surface of the right and left eyes, respectively. Contact between the bottle tip and the ocular or skin surface during attempted instillation occurred in 32.2% and 37.4% of subjects for the right and left eyes, respectively. The means and standard deviations for the number of eye drops expressed were 1.9 ± 1.6 and 1.8 ± 1.4 for the right and left eyes, respectively. Male gender (p=0.01), older age (p=0.005), and European ancestry (p=0.016) were associated with a statistically significantly lower likelihood of successful eye drop instillation on the ocular surface. Handedness, baseline diagnosis, number of medications in use, duration of prior eye drop use, visual acuity, and BMQ, REALM, and MMSE scores were not significantly associated with successful instillation.
Conclusions
A large proportion of glaucoma and OHT patients effectively, safely, and efficiently instilled eye drops. Male gender, older age, and European ancestry were associated with lower likelihood of successful instillation.
Keywords: 466 clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials