Eye Drop Instillation Success and Hand Function in Adults with Glaucoma: A Pilot Study

Abstract

Purpose: To investigate hand function and eye drop instillation success in adults with and without glaucoma.

Design: Cross-sectional pilot study.

Subjects: Adults aged ≥ 65 years with glaucoma who use eye drops daily and adults aged 65+ without glaucoma who do not regularly use eye drops.

Methods: Hand function was evaluated using the Saehan Hydraulic Pinch Gauge, Jamar Hand Dynamometer, Grooved Pegboard Test (GPT), Arthritis Hand Function Tests (AHFT), Semmes-Weinstein Monofilament Test, and a tactile pattern recognition device. Eye drop instillation success was analyzed through videography.

Main outcome measures: Proportion of successful eye drop instillation trials assessed by (1) overall success in getting at least one drop in the eye; (2) average number of drops dispensed; and (3) bottle tip contact with the eye, eyelashes, or skin. Hand function measures: mean pinch and grip strength, GPT and AHFT completion times, smallest detected monofilament, tactile pattern identification time, and accuracy.

Results: A total of 25 participants with glaucoma and 79 participants without glaucoma were included. There was no difference in the proportion of trials where at least one drop was successfully instilled, disregarding bottle tip contact (glaucoma: 0.95, nonglaucoma: 0.91; P = 0.88). Participants with glaucoma were more likely to make contact between the bottle tip and the eye, eyelashes, or skin compared with those without (glaucoma: 0.49, nonglaucoma: 0.28; P = 0.01). Participants with glaucoma dispensed a similar number of drops as those without (glaucoma: 1.37, nonglaucoma: 1.46; P = 0.47). Participants with glaucoma had significantly reduced pinch strength (glaucoma: 4.8 kg, nonglaucoma 6.1 kg, P = 0.01), grip strength (glaucoma: 23.4 kg, nonglaucoma: 27.7 kg, P = 0.02), longer completion times for the GPT (glaucoma: 113.5 seconds, nonglaucoma: 85.5 seconds, P = 0.02), and specific AHFT tasks of fastening/unfastening buttons (glaucoma: 36.6 seconds, nonglaucoma: 27.7 seconds, P = 0.03) and pinning/unpinning safety pins (glaucoma: 35.4 seconds, nonglaucoma: 27.3 seconds, P = 0.02), and worse tactile acuity on monofilament (P = 0.04) compared with participants without glaucoma.

Conclusions: Despite hand function deficits, in this exploratory pilot study, adults with glaucoma demonstrated eye drop instillation success comparable to those without glaucoma, though with higher rates of bottle tip contact with the eye, skin, or eyelashes, suggesting an increased risk of potential eye drop bottle contamination. These findings suggest that though regular practice may help mitigate the effects of hand function deficits on the targeted activity of getting the eye drop in the eye, the deficits may make this activity difficult.

Financial disclosure(s): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Keywords: Eye drop instillation success; Glaucoma; Hand function; Sensorimotor deficits.