What is atropine?
Atropine is a drug that is derived from the Atropa Belladonna plant. In Italian, belladonna means “beautiful woman”, and this name refers to the common practice of women in the 1300’s and 1400’s rubbing the leaves of the plant on their eyes to enlarge their pupils, believing this would make them more alluring. Atropine eye drops can slow myopia progression in children, called myopia control. There is a ‘dose dependent’ effect, which means that higher concentrations have stronger effects on slowing eye growth but also have more side effects.
- Concentrations of 0.01% to 0.05% are more commonly used for long-term myopia control and typically have only small effects on light sensitivity and close up vision.
- Atropine eye drops have a high safety profile when used normally.
Why is Low Dose Atropine used for myopia control?
Atropine has been shown to be highly effective in controlling progression of myopia. The first studies using atropine eye drops to slow myopia progression in children used 1% atropine, but these had significant side effects – enlarged pupils made a child sensitive to light, and blurred their close-up vision.
- Studies in the last 10 years have instead investigated lower concentrations, which have minimal side effects. The concentration of atropine eye drops which have been researched for myopia control vary from 0.01% right up to 1%. The best balance of minimal side effects with maximum effect to slow myopia progression seems to be found with 0.025% to 0.05% concentrations, based on current research.
- In myopia control, atropine drops are used once per day, at night time. It is not certain how atropine slows myopia progression in children. Scientists are still exploring the mechanism, which is likely how the atropine eye drops influence how chemical signals are conducted in the retina, the light sensitive layer at the back of the eye.
What are the potential side effects of using atropine for
Atropine’s effect on enlarging the pupil of the eye has already been covered above. It also impacts the focusing lens inside the eye, reducing the ability of the eye to adjust to focus on close up objects, causing blurred vision for reading and close work. This effect is most pronounced for atropine concentrations of 0.1% up to 1%.
These effects are useful when atropine 1% is used for eye examinations, lazy eye treatment in children, or to treat eye inflammation. In myopia control, though, these side effects are unwanted and can impact vision.
Fortunately, recent research has found that effective myopia control benefits of atropine can be achieved with 0.025% to 0.05% atropine concentration. At these low concentrations, atropine has been found to have minimal effect on pupil size and eye focusing, thereby greatly minimizing these unwanted side effects.