A video study of drop instillation in both glaucoma and retina patients with visual impairment

To compare self-administration of drops in both visually impaired glaucoma subjects and retina subjects.

Prospective, observational study.

Distinct glaucoma and retina practices.

Subjects with glaucoma or retinal diseases with visual acuity of 20/60 or worse in 1 eye, significant field loss, or both.

Subjects were video recorded self-instilling a drop onto the worse eye.

Proper instillation of eye drop onto ocular surface.

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).

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.