Randomized Trial to Evaluate the Efficacy of the Nanodropper Device for Pupillary Dilation and Cycloplegia in Children

We evaluated the noninferiority of 10.4 μl of eye drops eluted with a commercially available eye drop adapter, the Nanodropper (Nanodropper, Inc), on pupillary dilation and cycloplegia in children compared with the standard of care (SOC), 50 μl of eye drops. Prospective randomized trial. Pediatric patients scheduled for routine pupillary dilation at the University of California, San Francisco, at the Pediatric Ophthalmology Clinic were enrolled. Each participant provided 1 eye for the intervention group (Nanodropper) and 1 eye for the control group (SOC). Participants were randomized to receive small-volume dilating drops in 1 eye (Nanodropper) and SOC dilating drops in the other eye. Dilation was performed using 1 drop each of 1% cyclopentolate, 1% tropicamide, and 2.5% phenylephrine. Refraction and pupillometry were obtained before and 30 minutes after dilation. A noninferiority analysis was performed to assess change from before to after dilation in spherical equivalent and in pupil constriction percentage and maximum pupil diameter after dilation. Spherical equivalent, maximum pupil diameter, and pupil constriction percentage. One hundred eyes of 50 patients were included, with a mean ± standard deviation age of 9 ± 3 years. After controlling for baseline measurements, the spherical equivalent after dilation was 0.05 diopter (D) more (95% confidence interval [CI], –0.28 to 0.37 D) in the Nanodropper arm, which did not achieve noninferiority. Maximum pupil diameter after dilation was lower in the Nanodropper group (mean, –0.01 mm; 95% CI, –0.20 to –0.03), which did achieve noninferiority. Constriction percentage after dilation was 0.57 percentage points more (95% CI, –1.38 to 2.51 percentage points) in the Nanodropper group, which did not achieve noninferiority. Administration of eye drops using a small-volume adapter demonstrated similar efficacy to SOC in a pediatric population. Strict noninferiority was met only for pupillary dilation and not for cycloplegia or constriction percentage; however, the small differences in the effect of the Nanodropper versus SOC on all primary outcomes were not clinically significant. We conclude that small-volume eye drops have the potential to decrease unnecessary medical waste and medication toxicity while maintaining therapeutic effect. Proprietary or commercial disclosure may be found after the references.