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.