What is the principle of using 0.01% atropine sulfate eye drops to treat myopia? How does it work through pharmacological mechanisms?

Atropine sulfate eye drops 0.01% (EIKANCE) is a low-concentration anticholinergic drug mainly used to delay the progression of myopia in children and adolescents. It reduces the excessive growth of the eye axis by regulating eye muscles and nerve signals, thereby reducing the rate of progression of myopia.

The main mechanism of action of this drug is to block the M1 and M3 muscarinic receptors in the ciliary muscle, thereby inhibiting ciliary muscle overregulation. When the eyes are used at close range for a long time, the ciliary muscle contracts, causing changes in intraocular pressure, which may stimulate the eyeball to grow forward. Atropine sulfate relaxes the ciliary muscles and reduces the adjustment load, thereby reducing the speed of axial elongation and slowing down the progression of myopia.

Low concentrations of atropine may also affect signal transduction in the retina and sclera, inhibiting the expression of growth factors that promote axial growth. Studies have shown that atropine can reduce the activity of certain growth factors in the sclera, such as transforming growth factor TGF-β, thereby reducing abnormal eye development. This effect is different from traditional cycloplegia, but directly affects the growth mechanism of the eyeball to maintain its normal shape.

Compared with high concentrations (such as 1%) atropine sulfate, 0.01%atropine has fewer side effects, such as photophobia and a lower risk of decreased accommodation function, and is therefore more suitable for long-term use. Research shows that low-concentration atropine can not only effectively slow down the progression of myopia, but also maintain good tolerance and reduce the impact on daily learning and life. Therefore, it has become one of the commonly used treatment options to delay the progression of myopia.

Reference materials:https://www.medsafe.govt.nz/profs/datasheet/e/EikanceEyeDrops.pdf