A Video Study of Drop Instillation in Both Glaucoma and Retina Patients with Visual Impairment

Purpose To compare self-administration of drops in both visually impaired glaucoma subjects and retina subjects. Design Prospective, observational study. Methods Setting: Distinct glaucoma and retina practices. Study Population: Subjects with glaucoma or retinal diseases with visual acuity of 20/60 or worse in 1 eye, significant field loss, or both. Observation Procedures: Subjects were video recorded self-instilling a drop onto the worse eye. Main Outcome Measure: Proper instillation of eye drop onto ocular surface. Results We included 409 subjects (205 glaucoma, 204 retina). Differences between the groups included the following: glaucoma subjects included fewer females ( P = .05), included fewer white persons ( P < .005), had worse visual acuity ( P < .005), had less self-reported arthritis ( P < .05), were younger ( P < .005), and had more previous exposure to drop use ( P < .005). Glaucoma subjects had more bilateral impairment (60% vs 42%; P < .0005). Retina subjects instilled more drops (1.7 vs 1.4; P = .02) and more frequently touched the bottle to the eye (47% vs 33%; P = .003). Of subjects claiming not to miss the eye, nearly one third from each group ( P = .32) actually missed. Approximately one third of each group could not get a drop onto the eye (30% retina vs 29% glaucoma; P = .91). Among subjects placing 1 drop onto the eye without touching the adnexae, there was a trend for glaucoma patients to perform better, although both groups did poorly (success, 39% glaucoma vs 31% retina; P = .09). Conclusions Among visually impaired subjects, regardless of cause, drop administration was a problem. Both groups wasted drops, contaminated bottles, and had inaccurate perception of their abilities. This has implications for future therapeutic delivery systems.