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.