Impact of Various Concentrations of Low-Dose Atropine on Pupillary Diameter and Accommodative Amplitude in Children with Myopia.

Purpose: To assess over 2 weeks, the effect of 3 different low concentrations of atropine on pupillary diameter and accommodative amplitude in children with myopia. Methods: Fifty-eight children with myopia [spherical equivalent (SE) of -0.50 diopters (D) or worse, astigmatism of less than or equal to 2.00 D] were randomly allocated to 3 groups receiving 0.01%, 0.02%, or 0.03% atropine eye drops, once nightly for 2 weeks. The primary outcome was the change from baseline in pupillary diameter and accommodative amplitude with each of the concentrations. Results: Fifty-seven participants (114 eyes), aged between 6 and 12 years, completed the 2-week trial (mean age 9.3 ± 1.7 years and mean SE -3.53 ± 1.79 D). After 2 weeks of use, all the 3 concentrations were found to have a statistically significant effect on both the pupillary diameter and accommodative amplitude. Accommodative amplitude reduced by an average of 5.23 D, 9.28 D, and 9.32 D, and photopic pupil size increased by an average of 0.95 ± 1.05 mm, 1.65 ± 0.93 mm, and 2.16 ± 0.88 mm with 0.01%, 0.02%, and 0.03%, respectively. Of the eyes, a total of 5.3% and 5.9% of the eyes on 0.02% and 0.03% atropine had a mean residual accommodative amplitude of <5 D. The percentage of eyes having a pupillary dilation >3 mm were 4.8%, 10.5%, and 23.5% for 0.01%, 0.02%, and 0.03% atropine, respectively. Conclusions: Low-dose atropine had an effect on pupillary diameter and accommodative amplitude. With the highest concentration assessed, that is, 0.03% nearly 1 of 4 eyes had pupillary dilation of >3 mm. Clinical Trial Registration number: NCT03699423.

A Meta-Analysis Assessing Change in Pupillary Diameter, Accommodative Amplitude, and Efficacy of Atropine for Myopia Control.

PURPOSE: To determine the effect of atropine on pupillary diameter, accommodative amplitude as well as myopia progression. METHODS: Medical databases and Cochrane Library were systematically searched for studies from 1980 until June 2020. The primary and secondary outcomes were: a) change in pupillary diameter (PD) and accommodative amplitude (AA) and b) annualized mean change in spherical equivalent and axial length with various concentrations of atropine compared to control. RESULTS: Thirteen trials (6 RCTs, 7 observational studies) that studied 9 atropine concentrations (0.01-1.0%) were included. The relation between atropine and change in PD and AA was nonlinear; at < 0.10% atropine, the slope of the curve was steep but the change in PD (+0.7 mm; 95% CI: +0.1 to +1.4) and AA (-1.6D; 95% CI: -3.9 to +0.7) was smaller whereas at ≥0.10% atropine, the slope plateaued but change in PD (+3.2 mm, 95% CI: +2.8 to +3.5) and AA (-10.7D; 95% CI: -12.2 to -9.2) was high.Reduction in myopia progression with atropine at <0.10% and ≥0.10% as compared to controls was 0.37D (95% CI: 0.16 to 0.58) versus 0.75D (95% CI: 0.17 to 1.33) for spherical equivalent and -0.10 mm (95% CI: -0.24 to 0.05) versus -0.23 mm (95% CI: -0.34 to -0.13) for axial length. CONCLUSIONS: A nonlinear dose-response relationship exists between atropine and PD and AA. Further work is warranted to determine the concentration that provides maximal efficacy with tolerable side effects.

A Review of Myopia Control with Atropine.

Myopia is a global public health issue with a worldwide prevalence of ∼30% and is estimated to rise to 50% by 2050. In addition to the burden associated with routine management of the condition, high myopia predisposes the eye to sight-threatening complications such as myopic maculopathy and glaucoma in adult life. Controlling onset and progression of myopia at a young age can reduce the risk of morbidity associated with high myopia. Progression of myopia can be slowed with various optical, environmental, and pharmaceutical strategies, of which atropine has proven to be the most effective. High-dose atropine (0.5%-1%) is the most effective, but it has significant trade-offs with respect to rebound of myopia on discontinuation and side effects such as photophobia and difficulty with near work (decreased accommodation). Low doses of atropine have been trialed and show a dose-dependent efficacy. However, its mode of action on the ocular tissues leading to slowing eye growth remains unclear and multiple mechanisms and sites in the eye have been postulated to play a role. This review summarizes the role of atropine in controlling myopia and the mechanisms studied to date.