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.
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.