Binocular Visual Function of Young Myopic Adults Following Cessation of Long-term Atropine Use: Preliminary Learnings From a Pilot Case-control Cross-sectional Study

Myopia is a worldwide health concern due to its increasing prevalence and associated pathology, visual dysfunction, societal and quality of life impacts. Despite widespread use of atropine in Taiwan to manage myopia, its prevalence has increased. It has been suggested that the efficacy of atropine in slowing myopia progression may be limited by binocular vision (BV) function. Furthermore, the long-term impacts of atropine are unknown. This study aimed to contrast the BV profile of young myopic adults following cessation of atropine therapy for myopia control, relative to myopic adults without this history.

From a pool of young myopic adults attending a vision screening (n = 1320), 204 myopic (≤-0.50 dioptres, D) adults were invited for further clinical evaluation. Twenty-one control myopes (no prior atropine use) and 19 myopes treated previously with atropine (≥3 years) but ceased treatment (>1 year) were recruited.

Young adult myopes (19.05 [1.39] years) who had used atropine for at least 3 years and ceased treatment showed similar levels of myopia (-4.64 [2.45] versus -3.76 [2.20] D) and axial length (25.26 [1.09] versus 25.48 [1.11] mm) to controls (20.24 [2.39]). However, they were more esophoric at distance (-1.26 [2.94] versus 2.26 [4.96] Δ, p = 0.01) and showed reduced accommodative amplitude (16.16 [4.76] versus 12.51 [3.72] D, p = 0.01) and near negative fusional vergence (22.55 [1.39] versus 19.37 [1.34) Δ, p = 0.004). Accommodative facility and lag, positive fusional vergence, stereopsis, near point of convergence and near heterophoria were not significantly different.

Vergence and accommodation of young myopic adults following the cessation of long-term atropine therapy for myopia progression differed from that of young myopic adults with no prior atropine use. These findings suggest that BV function should be monitored for at least 12 months following the cessation of atropine treatment and even into early adulthood.