Efficacy and Adverse Effects of Atropine for Myopia Control in Children: A Meta-Analysis of Randomised Controlled Trials

Preservatives and pH in low-dose atropine formulations for clinical trials

Over a century ago, atropine has been tested to arrest myopia progression with good results. In recent years, many randomized clinical trials have tested different concentrations against placebo. Three recent such studies with low-dose atropine showed that it was less effective than previous studies, even the last one showing no difference in myopia progression between the treated and control group. Previous randomized studies had been performed in Asian populations, and these last three were extended to Western Caucasian populations, based on the initial observation that differences in iris pigmentation could be a factor for a difference in effectiveness. We have noticed that the three last studies in the West have used the same patented formulation, while previous studies have preferred compounded low-dose atropine. Here we review how the power of hydrogen (pH) and preservatives could account for differences in drug penetration to the eye, possibly explaining the differences between studies.

Low-dose atropine 0.01% for the treatment of childhood myopia: a pan-India multicentric retrospective study

OBJECTIVE

The objective of this study was to assess the efficacy of low-dose atropine 0.01% in controlling myopia progression among Indian children over a 2-year period.

METHODS

This retrospective study, conducted across 20 centres in India, monitored the progression of myopia over 2 years after initiating treatment with 0.01% atropine eye drops. This included children between 6 and 14 years with baseline myopia ranging from -0.5 D to -6 D, astigmatism≤-1.5 D, anisometropia ≤ -1 D and documented myopia progression of ≥0.5 D in the year prior to starting atropine. Subjects with any other ocular pathologies were excluded.

RESULTS

A total of 732 children were included in the data analysis. The mean age of the subjects was 9.3±2.7 years. The mean myopia progression at baseline (1 year before starting atropine) was -0.75±0.31 D. The rate of myopia progression was higher in younger subjects and those with higher baseline myopic error. After initiating atropine, myopia progression significantly decreased to -0.27±0.14 D at the end of the first year and -0.24±0.15 D at the end of the second year (p<0.001). Younger children (p<0.001) and higher baseline myopia (p<0.001) was associated with greater myopia progression and poor treatment response (p<0.001 for both).

CONCLUSION

Low-dose atropine (0.01%) effectively reduces myopia progression over 2 years in Indian children.

Comparison of the efficacy and safety of different doses of atropine for myopic control in children: a meta-analysis

Purpose: To comprehensively reassess the efficacy and safety of different concentrations of atropine for retarding myopia progression and seek the most appropriate therapeutic concentration for clinical practice. Methods: We searched PubMed, Cochrane Library, Embase, Chinese Science and Technology Periodicals (VIP) and China National Knowledege Infrastructure (CNKI) from their inception to 23 March 2023, to obtain eligible randomized controlled trials (RCTs) and cohort studies that had atropine in at least one treatment arm and placebo/no intervention in another arm. We evaluated the risk of bias of the RCTs according to the recommendations of the Cochrane Collaboration for RCTs and quality of cohort studies by the Newcastle‒Ottawa Scale. Weighted mean difference (WMD), 95% confidence interval were calculated for meta-analysis. All data analyses were performed using Review Manager 5.3, STATA 12.0 and SPSS 26.0 software. Results: A total of 44 studies were included in the meta-analysis. Weighted mean difference (WMD) were 0.73 diopters (D), 0.65 D, 0.35 D per year in refraction progression (χ 2 = 14.63, I 2 = 86.3%; p < 0.001) and -0.26 mm, -0.37 mm, -0.11 mm per year in axial length progression (χ 2 = 5.80, I 2 = 65.5%; p = 0.06) for high (0.5%-1%), moderate (0.1%-0.25%), and low (0.005%-0.05%) dose atropine groups, respectively. Logarithmic dose‒response correlations were found between atropine and their effect on change of refraction, axial length, accommodation and photopic pupil diameter. Through these curves, we found that atropine with concentrations ≤0.05% atropine resulted in a residual value of accommodation of more than 5 D and an increase in pupil diameter no more than 3 mm. Higher doses of atropine resulted in a higher incidence of adverse effects, of which the incidence of photophobia was dose-dependent (r = 0.477, p = 0.029). Conclusion: Both the efficacy and risk of adverse events for atropine treatment of myopia were mostly dose dependent. Comprehensively considered the myopia control effect and safety of each dose, 0.05% may be the best concentration of atropine to control myopia progression at present, at which myopia is better controlled and the side effects are tolerable. Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO/#recordDetails, CRD42022377705.

Efficacy and safety of atropine at different concentrations in prevention of myopia progression in Asian children: a systematic review and Meta-analysis of randomized clinical trials

AIM

To assess the efficacy versus the adverse effects of various concentrations of atropine in the prevention of myopia in Asian children.

METHODS

Databases (PubMed, EMBASE, the Cochrane Library and Web of science) were comprehensively searched from inception to April 2022. Types of studies included were randomized clinical trials (RCTs). The published languages were limited to English. Two researchers assessed the quality of included studies independently using Cochrane risk of bias tool based on the Cochrane Handbook for Systematic Reviews of Interventions. Funnel plots and Egger's test were used for detection of publication bias. Meta-analyses were conducted using STATA (version 15.0; StataCorp).

RESULTS

A total of 15 RCTs involving 2268 patients were included in the study. In the atropine group, spherical equivalent progressed at a significantly lower rate [weighted mean difference (WMD)=0.39, 95% confidence interval (CI): 0.23, 0.54] than in the control group. A WMD of 0.15 mm was associated with less axial elongation (95%CI -0.19, -0.10). Different doses showed statistically significant differences (P<0.05) and an improved effect could result from a higher concentration. Changes in photopic pupil size and mesopic pupil size in atropine group is 0.70 mm (95%CI: 0.33, 1.06) and 0.38 mm (95%CI: 0.22, 0.54) more than the control group. In the present Meta-analysis, no changes in accommodative amplitude (AA) were associated with atropine administration. Atropine administration increased the risk of adverse effects by 1.37 times.

CONCLUSION

Concentrations of less than 1% atropine are able to effectively retard diopter and axis growth of myopia in Asian children in a dose-dependent manner. Meanwhile, it caused pupil enlargement, but induced no change in the AA within this range. Further study is required to determine the dosage needed to achieve maximum efficacy and minimal side effects.

[Recommendations for Progressive Myopia in Childhood and Adolescence. Statement of the DOG, BVA and the Bielschowsky Society for Strabismus Research and Neuroophthalmology - Status June 2022]

Since the last and at the same time first statement of the German ophthalmological societies on the possibilities of reducing myopia progression in childhood and adolescence, many new details and aspects have emerged in clinical research. This second statement updates the previous document and specifies the recommendations on visual and reading behavior as well as on pharmacological and optical therapy options, which have been both refined and newly developed in the meantime.

Effectiveness of myopia control interventions: A systematic review of 12 randomized control trials published between 2019 and 2021

Purpose

This study aims to investigate the effectiveness of interventions to control myopia progression. In this systematic review, the primary outcomes were mean differences (MD) between treatment and control groups in myopia progression (D) and axial length (AL) elongation (mm).

Results

The following interventions were found to be effective (p < 0.001): highly aspherical lenslets (HAL, 0.80 D, 95% CI, 0.77-0.83; -0.35 mm, 95% CI -0.36 to -0.34), MiSight contact lenses (0.66 D, 95% CI, 0.63-0.69; -0.28 mm, 95% CI -0.29 to -0.27), low dose atropine 0.05% (0.54 D, 95% CI, 0.38-0.70; -0.21 mm, 95% CI-0.28 to -0.14), Biofinity +2.50 D (0.45 D, 95% CI, 0.29, 0.61; -0.24 mm, 95% CI -0.33 to -0.15), defocus incorporated multiple segments [DIMS] (0.44 D, 95% CI, 0.42-0.46; -0.34 mm, 95% CI -0.35 to -0.33) and ortho-k lenses (-0.24 mm, 95% CI -0.33 to -01.5).

Conclusion

Low-dose atropine 0.01% was not effective in reducing AL progression in two studies. Treatment efficacy with low-dose atropine of 0.05% showed good efficacy. Spectacles (HAL and DIMS) and contact lenses (MiSight and Biofinity) may confer a comparable treatment benefit compared to atropine, to slow myopia progression.

[Recommendations for progressive myopia in childhood and adolescence. Statement of the DOG, BVA and the Bielschowsky Society for Strabismus Research and Neuroophthalmology : Status June 2022]

Since the last and at the same time first statement of the German ophthalmological societies on the possibilities of reducing myopia progression in childhood and adolescence, many new details and aspects have emerged in clinical research. This second statement updates the previous document and specifies the recommendations on visual and reading behavior as well as on pharmacological and optical therapy options, which have been both refined and newly developed in the meantime.

Synergistic effects of defocus-incorporated multiple segments and atropine in slowing the progression of myopia

Myopia is a leading cause of visual impairment in young people worldwide. It sometimes increases the risk of blindness and reduces life quality. Previous reports have revealed the treatment effects of defocus-incorporated multiple segments (DIMS) and topical atropine (ATP) on myopia control. However, no study has evaluated these two interventions together. In this retrospective study, we aimed to determine whether the combination of DIMS lenses and 0.01% ATP can slow the progression of myopia compared with DIMS lenses or single vision (SV) lenses alone. We included 107 children with myopia who were treated with DIMS and 0.01% ATP combination (DIMS + ATP group), DIMS monotherapy (DIMS group), or a control group (SV group). We compared treatment effects among three groups in axial length and myopia progression. After a 1-year follow-up, the DIMS + ATP group showed a smaller change in axial length and myopia progression than the DIMS and SV groups (P < 0.05). Hence, combination treatment with DIMS and 0.01% ATP might be a better choice for children with myopia.