Prevalence of self-reported early glaucoma eye drop bottle exhaustion and associated risk factors: A patient survey

Background: One barrier to patient adherence with chronic topical glaucoma treatment is an inadequate amount of medication available between prescription refills. We examined the self-reported prevalence of early exhaustion of glaucoma eye drops prior to a scheduled refill, and associated risk factors. Methods. This cross-sectional survey was performed at a University-based clinical practice. Glaucoma patients at the University of Washington who were experienced with eye drop application and were on a steady regimen of self-administered glaucoma drops in both eyes took a survey at the time of clinic examination. The main outcome measure was self-reported early eye drop bottle exhaustion. Results: 236 patients were eligible and chose to participate. In general, patients included were relatively healthy (mean 2.3 comorbid medical conditions). Sixty patients (25.4%) reported any problem with early exhaustion of eye drop bottles, and this was associated with visual acuity ≤ 20/70 in the better eye (P =.049). Twelve patients (5.1%) reported that they "often" (5-7 times per year), "usually" (8-11 times per year) or "always" ran out of eye drops prior to a scheduled refill. Patients affected by this higher level (≥5 times yearly) of eye drop bottle exhaustion were more likely to have poor visual acuity in their worse eye ≤ 20/70 (P =.015) and had significantly lower worse-eye logMAR (P =.043). Conclusions: Self-reported early glaucoma bottle exhaustion regularly affected 5% of patients in our population and 25% reported early exhaustion at least once; the main risk factor was poor vision in at least one eye. These results may not be generalizable to a broad patient population, or to those inexperienced with eye drop self-administration. However, this pilot study compels further evaluation and consideration of early eye drop bottle exhaustion in glaucoma patients.