Low-dose Atropine Can Significantly Alter Binocular Vision

A new study published in Ophthalmic and Physiological Optics sought to understand how low-dose atropine affects binocular vision parameters—such as accommodation and convergence—in young adults with myopia. The findings indicated that the application of 0.05% atropine over a span of 10 days led to a clinically significant disruption in the accommodative function, with an average decrease of approximately 6.00D in binocular amplitude of accommodation by day 10.  Researchers argue that the ongoing use of atropine to control myopia necessitates monitoring of near heterophoria and fusional reserves, especially in children who rely heavily on near-vision tasks. These graphs from the study show differences in (a) binocular accommodative amplitude, (b) positive (closed data points) and negative (open data points) relative accommodation, (c) binocular accommodative facility and (d) accommodative posture. Photo: Woodman-Pieterse EC, et al.Ophthalmic Physiol Opt. September 5, 2025. Click image to enlarge. A total of 60 participants aged 18 to 30 years were included, with individuals randomly assigned to receive either atropine (0.05%) or a placebo. Over the course of 10 days, participants underwent a series of standardized measurements to assess their accommodative function and binocular vision parameters. The primary outcome measures involved the amplitude of accommodation, which was quantified both monocularly and binocularly, as well as assessments of near point of convergence (NPC) and heterophoria. The baseline assessments indicated that participants had a mean monocular amplitude of accommodation of 9.80D.The data revealed a statistically significant reduction in accommodative amplitudes among participants using atropine, with reductions around 3.00D at day three, increasing to an average loss of 6.00D by day 10. The researchers explained in their paper that while this finding is not surprising, given atropine’s mechanism of action, previous studies reported lesser degrees of accommodation reduction. For instance, the Low-concentration Atropine for Myopia Progression (LAMP) study indicated a mean loss of only 2.30D after two weeks of nightly use of 0.05% atropine in a younger population.In terms of heterophoria, the atropine group shifted from an average near heterophoria of +1.4 prism diopters at day three to +5.0 by day 10, indicating a marked increase in esophoria. Furthermore, measurements of positive relative accommodation reflected a substantial decline, with values decreasing to -0.68D in the atropine group after 10 days.“The concern these findings raise,” the researchers surmised, “is that in the long term, an increased tendency to converge at near, coupled with decreased divergence capacity, may lead to an increase in medial rectus muscle tone and the eventual development of esotropia in susceptible individuals.” They added, “The differences between the findings of the present study using 0.05% atropine in older participants compared to those using lower concentrations in younger cohorts may suggest that 0.01% is a ‘safe’ concentration that is less detrimental to binocular vision than 0.05%.” However, they pointed out that in recent years, several case reports have shown that 0.01% atropine could also have a significant effect on binocular vision.In summary, these results suggest that low-dose atropine significantly impairs accommodative function while also affecting binocular alignment, necessitating careful monitoring and consideration for optometrists managing myopic patients, particularly children, who rely heavily on their near vision capabilities. The researchers argued, “Baseline binocular vision status should be considered carefully prior to prescribing low dose atropine eye drops for myopia control, and monitored from as early as one to two weeks after commencing treatment.” Moreover, “Practitioners should ensure that near heterophoria and fusional reserves are tested routinely in patients treated with 0.05% atropine, in addition to tests of accommodative function,” they wrote.Click here for the journal source. Woodman-Pieterse EC, Hughes RPJ, Hopkins S, et al. Response of accommodation and vergence systems to low dose atropine. Ophthalmic Physiol Opt. September 5, 2025. [Epub ahead of print]. This article was developed by the editorial staff in conjunction with experts in the field. In the process, AI may have been among the editorial tools used to meet the goals of human editors, who approved all content.