Videotaped evaluation of eyedrop instillation in glaucoma patients with visual impairment or moderate to severe visual field loss.

PURPOSE: Objectively evaluate the ability of visually disabled glaucoma patients to successfully administer a single drop onto their eye.
DESIGN: Prospective, observational study. PARTICIPANTS: Experienced glaucoma patients with Early Treatment of Diabetic Retinopathy Study visual acuity (VA) of ≤ 6/18 (≤ 20/60) ≥ 1 eye, or moderate or severe visual field damage in ≥ 1 eye.
METHODS: Subjects were "low vision" (20/60 ≤ VA <20/200) or "blind" (light perception <VA ≤ 20/200). They completed a survey about eyedrop use, and were video-recorded instilling 1 drop into their worst-seeing eye in their usual fashion, using a 5-ml bottle. MAIN OUTCOME MEASURES: Successful instillation of a single drop.
RESULTS: Of 204 glaucoma subjects (55% female; 74% Caucasian; 89% primary open-angle glaucoma; mean age, 68.8 ± 13.1 years), 192/204 (94%) used drops >6 months. Subjects used a mean of 1.9 ± 1.1 bottles of intraocular pressure-lowering medications to treat their glaucoma. Seventy-six percent (155/204) of subjects had severe visual field damage, with a mean deviation of -14.5 ± 8.0. Twenty-six percent (54/204) had acuity of ≤ 20/200 in ≥ 1 eye, and subjects had a mean logarithm of minimal angle of resolution acuity of 0.8 ± 0.9. Seventy-one percent of subjects were able to get a drop onto the eye; only 39% instilled 1 drop onto the eye without touching the ocular surface, instilling a mean 1.4 ± 1.0 drops, using 1.2 ± 0.6 attempts. Of the 142 subjects who denied touching the bottle to the ocular surface, 24% did touch the bottle to the eye. Multiple factors were tested for ability to predict successful application of an eyedrop; however, only age (< 70 vs ≥ 70 years) was found to be a significant predictor for less successful instillation.
CONCLUSIONS: In this video analysis of visually impaired glaucoma patients, we evaluated the difficulty this population has instilling eyedrops, most important, the use of multiple drops per instillation, potential contamination of a chronically used bottle, and poor patient understanding of the situation. Ability to self-administer eyedrops and cost considerations of wasted drops must be thought out before institution of glaucoma therapy. Efforts to determine better methods of eyedrop administration need to be undertaken.