Groundbreaking research originating from the University of Houston has brought new insights into the management of myopia, or nearsightedness, a prevalent visual disorder affecting approximately one-third of adults in the United States. The study focuses on the use of a single low-dose atropine eye drop and its lasting physiological effects. Unlike prior assumptions that multiple or continuous applications were needed to elicit significant change, the new findings reveal that even one drop of low-concentration atropine, ranging from 0.01% to 0.1%, can trigger modifications in ocular function that endure for an entire day. This discovery opens new avenues in myopia treatment protocols, emphasizing efficiency and patient compliance.
The research team, led by Professor Lisa Ostrin of the University of Houston’s Optometry department alongside postdoctoral scholar Barsha Lal, conducted a rigorous evaluation of atropine’s immediate impacts on the eye’s structure and function. Through controlled, double-masked, and randomized clinical trials involving healthy young adults, they demonstrated that a solitary atropine drop alters crucial parameters such as pupil size and accommodation—the eye’s ability to focus on near objects—for up to 24 hours post-application. Importantly, these functional changes occur without provoking any short-term anatomical alterations in ocular tissues, underscoring atropine’s efficacy as a low-risk intervention.
Delving deeper into ocular physiology, the team assessed the drug’s influence on retinal and choroidal anatomy. The retina—the light-sensitive tissue lining the back of the eye—and the choroid—a vascular layer supplying nutrients to the retina—are central to maintaining visual acuity. Myopia is well-known for its association with elongation of the axial length of the eye, leading to stretching and thinning of these layers, which compromises vision. Ostrin’s study found that atropine application had no measurable effect on axial length nor on retinal or choroidal thickness within a 24-hour observation window, highlighting the selectivity of atropine’s action.
The research further explored ocular blood flow changes, noting transient modulation of retinal perfusion shortly after atropine instillation. This temporary alteration in blood vessel function may be linked to atropine’s pharmacologic properties as a muscarinic receptor antagonist, which influences autonomic control over vascular tone. These findings suggest that while atropine modulates eye function and vascular responses acutely, it does not produce lasting structural disruptions, a critical consideration for safety in clinical use.
The study’s design included repeated sessions where twenty participants received either the atropine drops or placebo under controlled conditions. Measurements of ocular parameters were meticulously taken at one hour and twenty-four hours post-dose to gauge both immediate and sustained effects. This methodical approach enabled the researchers to distinctly attribute observed physiological changes to atropine and to understand the duration of its influence on visual function.
Professor Ostrin emphasizes that objective measurements of pupil response and accommodative behavior are vital for interpreting how atropine mediates myopia control. Her previous studies have shown similar pupil dynamics after atropine administration, supporting a consistent biological effect that correlates with subjective visual experiences. Such results pave the way for evidence-based ocular therapeutics that are personalized, optimizing dosage and frequency based on measurable physiological responses rather than generalized treatment guidelines.
Beyond the scope of this individual study, the University of Houston is also contributing to larger clinical efforts to combat myopia progression. Co-led by David Berntsen, Golden-Golden Professor of Optometry, a $25 million national clinical trial funded by the National Institutes of Health is currently underway. This ambitious project investigates atropine’s capacity to delay the onset and progression of myopia in children, potentially curbing the rising global burden of nearsightedness and its associated ocular complications.
By establishing that low-dose atropine acts predominantly through functional modulation without structural alteration, the research offers clinicians a refined understanding of drug action in the human eye. The transient impact on retinal blood flow adds a new dimension to considerations of atropine’s pharmacodynamics, underscoring the necessity of integrating vascular health monitoring in therapeutic regimens.
In sum, this pioneering research not only redefines the pharmacological timeline of atropine’s effects but also reassures both practitioners and patients about its safety profile. It reinforces the potential for atropine to be used as an individualized, low-risk intervention against myopia progression—a condition that if unaddressed, can lead to serious visual impairment, including retinal detachment, glaucoma, and macular degeneration.
The findings, published in the journal Eye and Vision, contribute significantly to the ophthalmologic and optometric literature by clarifying the short-term ocular responses to atropine. This enhanced scientific understanding aids in clarifying mechanisms by which atropine mitigates myopia progression and fosters evidence-based treatment models, improving patient outcomes.
As myopia prevalence continues to rise globally, innovative strategies such as this study highlight the critical role of translational research in bridging laboratory findings with real-world clinical applications. The work of Ostrin and colleagues exemplifies how targeted physiological investigations can lead to transformative advances in eye care practices, promising to alleviate the visual burden for millions worldwide.
Ultimately, by linking objective ocular alterations with subjective patient experiences, this research ushers a new era of personalized myopia management. Through precise dosing and thorough understanding of atropine’s effects, eye care professionals can optimize therapeutic approaches, mitigating risks and enhancing visual health across populations.
Subject of Research: Short-term effects of low-dose atropine on the retina, choroid, and functional ocular parameters in young adults
Article Title: Short-term effects of atropine on the retina and choroid in young adults
News Publication Date: 1-Mar-2026
Web References:
https://link.springer.com/article/10.1186/s40662-026-00477-1
https://www.uh.edu/news-events/stories/2025/september/09182025-berntsen-atropine-drops-study.php
https://pubmed.ncbi.nlm.nih.gov/40492989/
References: Published study in Eye and Vision journal by Lisa Ostrin and team
Image Credits: University of Houston
Keywords
Myopia, atropine, low-dose atropine, retinal perfusion, choroidal thickness, axial length, pupil size, accommodation, eye structure, vision disorders, ocular pharmacology, clinical optometry, myopia management
