Atropine Eye Drops in Childhood Myopia Control: A Review.

Myopia is a pandemic problem in this world. Per 2019 report of the World Health Organization in their first-ever report on vision, ~27% world's population are suffering from myopia. This trend is expected to increase to ~50% by 2050. Unfortunately, no cure method is available so far due to its complications of the mechanistic actions. Therefore, control of myopia is the focus clinically. Currently, it is suggested that 0.05% atropine is optimal, balanced in efficacy and rebound in controlling myopia initiation and progression. In such a control process, measurement of reduction in spherical equivalent refraction (SER) progression and axial length (AL) elongation are critical for efficacy and rebound of atropine eye drops. For example, in Low-concentration Atropine for Myopia Progression (LAMP) study over one year, 0.05%, 0.025%, and 0.01% atropine can reduce SER progression by 67%, 43%, and 27%, decrease AL elongation by 51%, 29%, and 12%, respectively, while 0.5%, 0.1%, and 0.01% atropine may increase rebound by 68.4%, 58.9%, and 24.3%, respectively. Mechanistically, atropine, a muscarinic receptor antagonist, is used as the primary medication for controlling myopia due to its effectiveness and affordability. In this review, we provide a concurrent view of myopia epidemiology, atropine use to control myopia, its tentative mechanism, balance of its effects as well as side effects, and its clinical application methods in hope for clinical ophthalmologists to effectively control this problematic disease worldwide.