Study: Low-dose eye drops manage adult myopia for 24 hours

Investigators from the University of Houston reported that one drop of low-dose atropine (0.01%-0.1%) can manage myopia in young adults for an entire day,¹ according to a press release issued by the university.

The investigators, Barsha Lal, PhD, and Lisa Ostrin, OD, PhD, from the University of Houston College of Optometry, reported their findings in Eye and Vision.

They explained that while low-dose atropine slows myopia progression in children, the short-term effects on the retina and choroid are incompletely understood.

Investigators undertook this study to determine the drug’s short-term effects on axial length, retinal and choroidal thickness, and microvasculature.

The double-masked, randomized study, included 20 healthy adults (mean age, 25.5 years; mean refraction, − 1.9 ± 2.2 diopters) who were treated with either 1 drop of placebo or 1 drop of 0.01%, 0.025%, 0.05%, or 0.1% atropine in the right eye during five separate sessions.

The following parameters were measured at baseline and 1 and 24 hours after instillation of drops: retinal and choroidal thicknesses in the central 1.0-mm diameter and 1.0–3.0-mm annulus, perfusion density in the superficial and deep vascular complex and choriocapillaris in the central 1.0-mm and 1.0–2.5-mm annulus, foveal avascular zone, and axial length, Lal and Ostrin explained.

They found that one drop of low-dose atropine (0.01%–0.1%) “produced clear changes in pupil size and focusing ability that persist for at least 24 hours. Importantly, they also found that the drop showed no short-term structural effects on the eye, with only temporary changes in blood flow inside the retina,” according to the press release.

Specifically, there were no significant changes in retinal or choroidal thickness or axial length observed with any atropine concentration or time point (P > 0.05). “The superficial vascular plexus perfusion density in the 1.0–2.5-mm annulus showed a significant decrease (P = 0.02) with time after atropine instillation but not with concentration (P > 0.05); post hoc analysis showed a significant decrease from baseline at 1 hour (P = 0.03) compared to 24 hours (P = 0.28).”¹

“Characterizing these short-term effects is important for a better understanding of the physiological responses to atropine in clinical and research settings. By linking objective ocular responses with subjective visual experience, this work advances our understanding of how atropine works and supports more precise, evidence-based, and individualized approaches to myopia management,” Ostrin said.

Reference:

1. Lal B, Ostrin LA. Short-term effects of atropine on the retina and choroid in young adults. Eye and Vis. 2026;13:8. https://doi.org/10.1186/s40662-026-00477-1