Atropine eye drops have a long history of use in the treatment of myopia.1 However, little is known on its mechanism of action and possible long-term side effects.
Most early uses of atropine utilized 1.0% formulations. While this concentration appeared to effectively control myopia, atropine was never accepted as mainstream treatment due to concerns about side effects (i.e., significant pupil dilation, photophobia, severe accommodative dysfunction). Clinical trials indicate an acceleration of myopia progression after abruptly stopping treatment.2
Recently, low-dose atropine (0.01%) has been widely adopted to help reduce the risk of dose-dependent side effects. A clinical trial indicated a 60% reduction in myopia progression vs. historical control, with significantly less rebound effects.2 However, there is no evidence that this dose results in less axial elongation. A number of studies are currently in progress to more thoroughly study 0.01% atropine as a myopia treatment.
The Use of Atropine for Myopia Control
In treating myopia, the atropine dose must be tailored to the needs of the patient. For example, a younger patient with higher myopia may benefit from a higher dose. Since low-dose atropine is only available from compound pharmacies, 0.01% formulations are often the only strength available. For a higher dose (0.02%), consider using two drops spaced five minutes apart. High costs associated with compound pharmacies may be a patient barrier to consider.
Consideration should be given on whether to use non-preserved formulations, which may be associated with a risk of infection vs. drops preserved with benzalkonium chloride, which carries a risk of corneal toxicity and dry eye.
Knowledge Gap for Atropine Use in Myopia
As clinical evidence is scarce on the use of atropine in myopia, a number of questions remain that require further investigation:
- Can tapering the dose (vs. abrupt discontinuation) help mitigate rebound effects?
- What is the best way to taper the dose? (e.g., reducing one day’s treatment/week combined with a percentage decrease)
- With a sustained effect observed with a single drop, is a once daily dose necessary? Could once weekly be sufficient?
- Could a less frequent dose or regular weekend “drug holidays” maintain an adequate treatment effect while reducing the risk of rebound?
- Bedrossian, R. H. The effect of atropine on myopia. Ann Ophthalmol 3, 891-897 (1971).
- Tong, L. et al. Atropine for the treatment of childhood myopia: effect on myopia progression after cessation of atropine. Ophthalmology 116, 572-579, doi:10.1016/j.ophtha.2008.10.020 (2009).