What is the principle of 0.01% atropine sulfate eye drops in treating myopia? How long does it take to take effect?

The principle of Atropine Sulfate 0.01% eye drops (Atropine Sulfate 0.01%) for treating myopia is mainly to reduce the elongation of the eye axis by inhibiting the adjustment function of the ciliary muscle of the eye, thereby slowing down the development of myopia. Atropine is a parasympathetic depressant that relaxes the ciliary muscles of the eye and reduces the eye's need to adjust to close objects. At low concentrations, atropine has a mild effect on the ciliary muscle, which can effectively reduce the growth rate of the eye axis and slow down the progression of myopia. This mechanism makes atropine one of the effective treatment options for controlling the progression of myopia in children and adolescents.

Unlike traditional myopia correction methods (such as wearing glasses or contact lenses), 0.01% atropine sulfate intervenes in the progression of myopia by acting on the physiological mechanism of the eye. The occurrence of myopia is related to the growth of the axial length of the eyeball. Excessive axial growth will lead to poor vision. By reducing the adjustment effect of the ciliary muscle, atropine eye drops can reduce the speed of axial elongation without changing the diopter, thereby delaying the progression of myopia. Therefore, it is an interventional treatment rather than merely correcting existing myopia.

The effects of using 0.01% Atropine Sulfate Eye Drops usually take some time to appear. According to multiple clinical studies, it usually takes several months of continued use to see significant results. Studies have shown that patients who use atropine eye drops for a long time (such as once a day) have a significantly slower progression of myopia than non-users. Typically, within 6 months to 1 year of treatment, patients' myopia progression rate is reduced by about 50%. Therefore, although treatment can significantly delay the progression of myopia, it will take sufficient time to see significant results.
The effects of treatment may vary among individuals, with some patients seeing results within a few months, while others may take longer to see changes. In practical applications, doctors usually recommend that patients continue to use atropine eye drops and undergo regular eye examinations to evaluate the treatment effect and adjust the treatment plan as needed.
Reference: https://www.medsafe.govt.nz/profs/datasheet/e/EikanceEyeDrops.pdf