Analysis of Factors That May Affect the Effect of Atropine 0.01% on Myopia Control

0.01% Atropine Eye Drops in Children With Myopia and Intermittent Exotropia: The AMIXT Randomized Clinical Trial

Importance

Exotropia and myopia are commonly coexistent. However, evidence is limited regarding atropine interventions for myopia control in children with myopia and intermittent exotropia (IXT).

Objective

To evaluate the efficacy and safety of 0.01% atropine eye drops on myopia progression, exotropia conditions, and binocular vision in individuals with myopia and IXT.

Design, Setting, and Participants

This placebo-controlled, double-masked, randomized clinical trial was conducted from December 2020 to September 2023. Children aged 6 to 12 years with basic-type IXT and myopia of -0.50 to -6.00 diopters (D) after cycloplegic refraction in both eyes were enrolled.

Intervention

Participants were randomly assigned in a 2:1 ratio to 0.01% atropine or placebo eye drops administered in both eyes once at night for 12 months.

Main Outcomes and Measures

The primary outcome was change in cycloplegic spherical equivalent from baseline at 1 year. Secondary outcomes included change in axial length (AL), accommodative amplitude (AA), exotropia conditions, and binocular vision at 1 year.

Results

Among 323 screened participants, 300 children (mean [SD] age, 9.1 [1.6] years; 152 male [50.7%]) were included in this study. A total of 200 children (66.7%) were in the atropine group, and 100 (33.3%) were in the placebo group. At 1 year, the 0.01% atropine group had slower spherical equivalent progression (-0.51 D vs -0.75 D; difference = 0.24 D; 95% CI, 0.11-0.37 D; P < .001) and AL elongation (0.31 mm vs 0.42 mm; difference = -0.11 mm; 95% CI, -0.17 to -0.06 mm; P < .001) than the placebo group. The mean AA change was -3.06 D vs 0.12 D (difference = -3.18 D; 95% CI, -3.92 to -2.44 D; P < .001) in the atropine and placebo groups, respectively. The 0.01% atropine group had a decrease in near magnitude of exodeviation whereas the placebo group had an increase (-1.25 prism diopters [PD] vs 0.74 PD; difference = -1.99 PD; 95% CI, -3.79 to -0.19 PD; P = .03). In the atropine vs placebo group, respectively, the incidence of study drug-related photophobia was 6.0% (12 of 200 participants) vs 8.0% (8 of 100 participants; difference = -2.0%; 95% CI, -9.4% to 3.7%; P = .51) and for blurred near vision was 6.0% (12 of 200 participants) vs 7.0% (7 of 100 participants) (difference = -1.0%; 95% CI, -8.2% to 4.5%; P = .74).

Conclusions and Relevance

The findings of this randomized clinical trial support use of 0.01% atropine eye drops, although compromising AA to some extent, for slowing myopia progression without interfering with exotropia conditions or binocular vision in children with myopia and IXT.

Trial Registration

Chinese Clinical Trial Registry Identifier: ChiCTR2000039827.

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.

Myopia Controlling using Low Dose Atropine Eye Drop

Purpose

To determine myopic progression, axial length elongation, best-corrected visual acuity (BCVA), pupil dilation, and accommodation amplitude following 24 months of Atropine 0.01% usage among progressive myopic patients.

Methods

Fifty-one progressive myopic patients (age range, 3.5-17 years) were included in the present study. Fifteen patients were excluded due to loss to follow-up (eight patients) and Atropine complications (seven patients) and 36 patients continued therapy. Myopic progression, axial length, far and near BCVA, pupil diameter, and accommodation amplitude were measured at baseline examination and repeated every 6 months up to 2 years. All patients were recommended to instill one drop of Atropine 0.01% in each eye every night. Absolute success of therapy was defined as myopic progression ≤0.50 diopter (D) and axial length growth ≤0.2 mm per year.

Results

Mean myopic progression was 0.16 and 1.28 D and mean axial length change was 0.05 and 0.69 mm at months 12 and 24, respectively. Pupil dilation was 1.26 and 1.84 mm and accommodation reduction was 3.38 and 3.37 D at the same follow-ups, while BCVA was not changed. Absolute success rate for myopic progression control was 56.8% at 12 months and 70.8% at 24 months follow-up. In addition, the success rate in respect to axial length changes was 44.4% and 58.3% at the same time points.

Conclusions

Atropine 0.01% can slow myopic progression and axial length elongation at least in 50% of myopic cases at 12- and 24-month follow-up with no significant complications. Therefore, Atropine therapy is recommended in cases of progressive myopia in children and teenagers.

Atropine Ophthalmic Solution to Reduce Myopia Progression in Pediatric Subjects: The Randomized, Double-Blind Multicenter Phase II APPLE Study

PURPOSE

The purpose of this study was to assess the dose-response effects of low-dose atropine on myopia progression and safety in pediatric subjects with mild-to-moderate myopia.

METHODS

This phase II, randomized, double-masked, placebo-controlled study compared the efficacy and safety of atropine 0.0025%, 0.005%, and 0.01% with placebo in 99 children, aged 6-11 years, with mild-to-moderate myopia. Subjects received 1 drop in each eye at bedtime. The primary efficacy endpoint was change in spherical equivalent (SE), while secondary endpoints included changes in axial length (AL) and near logMAR (logarithm of the minimum angle of resolution) visual acuity and adverse effects.

RESULTS

The mean±SD changes in SE from baseline to 12 months in the placebo and atropine 0.0025%, 0.005%, and 0.01% groups were -0.55±0.471, -0.55±0.337, -0.33±0.473, and -0.39±0.519 D, respectively. The least squares mean differences (atropine-placebo) in the atropine 0.0025%, 0.005%, and 0.01% groups were 0.11 D ( P =0.246), 0.23 D ( P =0.009), and 0.25 D ( P =0.006), respectively. Compared with placebo, the mean change in AL was significantly greater for atropine 0.005% (-0.09 mm, P =0.012) and 0.01% (-0.10 mm, P =0.003). There were no significant changes in near visual acuity in any of the treatment groups. The most common ocular adverse events were pruritus and blurred vision, each occurring in 4 (5.5%) atropine-treated children. Changes in mean pupil size and amplitude of accommodation were minimal.

CONCLUSIONS

Atropine doses of 0.005% and 0.01% effectively reduced myopia progression in children but no effect was noted with 0.0025%. All doses of atropine were safe and well tolerated.

Effect of atropine 0.01% on myopia control in children aged 6-13 years during the 2022 lockdown in Shanghai

Purpose

To compare the myopic progression in children treated with 0. 01% atropine and those who discontinued atropine during the 2022-home quarantine in Shanghai.

Methods

In this retrospective study, children aged 6-13 years with follow-up visits before (between January 2022 and February 2022) and after the lockdown (between July 2022 and August 2022) were included. Cycloplegic refraction and axial length (AL) were measured at both visits. The atropine group had continuous medication during the lockdown while the control group discontinued. The 0.01% atropine eyedrops were administered daily before bedtime. The types of spectacle lens were recorded: single vision (SV) spectacles or defocus incorporated multiple segments lenses (DIMS).

Results

In total, 41 children (81 eyes) in the atropine group and 32 children (64 eyes) in the control group were enrolled. No significant difference was found in the demographic characteristics, spherical diopter, spherical equivalent (SE), AL, and follow-up time between the two groups before the lockdown in 2022 (all p > 0.1). After the home confinement, a greater myopia progression was observed in the control group (-0.46 ± 0.42 D) compared to atropine group (-0.26 ± 0.37 D; p = 0.0023). Axial elongation was also longer in the control group than that in children sustained with atropine (0.21 ± 0.17 vs. 0.13 ± 0.15 mm, p = 0.0035). Moreover, there was no significant change of spherical diopter and SE during lockdown in the atropine + DIMS combined subgroup (0.03 ± 0.033 D for spherical diopter, p = 0.7261 and 0.08 ± 0.27 D for SE, p = 0.2042, respectively). However, significant myopic shift was observed in the atropine + SV subgroup during the quarantine time (-0.31 ± 0.39 D for SE and 0.15 ± 0.16 mm for AL, both p < 0.001).

Conclusion

Children treated with 0.01% atropine had slower myopia progression during the lockdown period in Shanghai compared with children discontinued. Moreover, the effect of atropine on myopic prevention can be strengthened with DIMS lenses.

Factors Related to Axial Length Elongation in Myopic Children Who Received 0.05% Atropine Treatment

Purpose: To evaluate the longitudinal changes of axial length (AL) and factors associated with AL growth in myopic children receiving 0.05% atropine. Methods: This single-center retrospective study included children aged 4-13 years with myopia of at least -0.5 diopters (D) treated with 0.05% atropine eye drops from November 2016 to May 2021. Predictive factors for AL change were evaluated using linear mixed models. Results: Among 109 patients (218 eyes), 58 (53.2%) were male and the mean age at treatment was 8.5 ± 2.0 years. At baseline measurement, the mean spherical equivalent was -4.05 ± 2.34 diopters (D), and AL was 25.00 ± 0.97 mm. The mean follow-up duration was 25.4 (12-58) months, and the mean AL elongation was 0.23 ± 0.17 mm/year during the follow-up periods. AL shortening of ≥0.05 mm at subsequent visit occurred in 18 patients (26 eyes). The mean AL change in the group without initial AL shortening was statistically larger than that in the group with initial AL shortening (0.26 ± 0.16 mm/year vs. 0.02 ± 0.17 mm/year, P < 0.001). In linear mixed model, the age at atropine treatment and initial AL shortening were significantly associated with respect to AL growth (beta coefficient: -0.032 and -0.122, respectively, P < 0.001 for both). Conclusions: Our study found that older age and initial AL shortening are predictors of favorable response after 0.05% atropine treatment. Children with AL shortening at initial subsequent visit may be associated with good long-term response, and younger children may require higher concentration of atropine for optimal response.

Corneal Penetration of Low-Dose Atropine Eye Drops

Major studies demonstrating the inhibition of myopia in children and juveniles by low-dose atropine eye drops provide little information on the manufacturing process and the exact composition of the atropine dilutions. However, corneal penetration might significantly vary depending on preservatives, such as benzalkonium chloride (BAC), and the atropine concentration. Since there is a trade-off between side effects, stability, and optimal effects of atropine on myopia, it is important to gain better knowledge about intraocular atropine concentrations. We performed an ex vivo study to determine corneal penetration for different formulations. Atropine drops (0.01%) of different formulations were obtained from pharmacies and applied to the cornea of freshly enucleated pig eyes. After 10 min, a sample of aqueous humor was taken and atropine concentrations were determined after liquid–liquid extraction followed by high-performance liquid chromatography–tandem mass spectrometry (LC-MS/MS). The variability that originated from variations in applied drop size exceeded the differences between preserved and preservative-free formulations. The atropine concentration in the anterior chamber measured after 10 min was only 3.8 × 10⁻⁸ of its concentration in the applied eye drops, corresponding to 502.4 pM. Obviously, the preservative did not facilitate corneal penetration, at least ex vivo. In the aqueous humor of children’s eyes, similar concentrations, including higher variability, may be expected in the lower therapeutic window of pharmacodynamic action.

Age Effect on Treatment Responses to 0.05%, 0.025%, and 0.01% Atropine: Low-Concentration Atropine for Myopia Progression Study

PURPOSE

To investigate the effect of age at treatment and other factors on treatment response to atropine in the Low-Concentration Atropine for Myopia Progression (LAMP) Study.

DESIGN

Secondary analysis from a randomized trial.

PARTICIPANTS

Three hundred fifty children aged 4 to 12 years who originally were assigned to receive 0.05%, 0.025%, or 0.01% atropine or placebo once daily, and who completed 2 years of the LAMP Study, were included. In the second year, the placebo group was switched to the 0.05% atropine group.

METHODS

Potential predictive factors for change in spherical equivalent (SE) and axial length (AL) over 2 years were evaluated by generalized estimating equations in each treatment group. Evaluated factors included age at treatment, gender, baseline refraction, parental myopia, time outdoors, diopter hours of near work, and treatment compliance. Estimated mean values and 95% confidence intervals (CIs) of change in SE and AL over 2 years also were generated.

MAIN OUTCOME MEASURES

Factors associated with SE change and AL change over 2 years were the primary outcome measures. Associated factors during the first year were secondary outcome measures.

RESULTS

In 0.05%, 0.025%, and 0.01% atropine groups, younger age was the only factor associated with SE progression (coefficient of 0.14, 0.15, and 0.20, respectively) and AL elongation (coefficient of -0.10, -0.11, and -0.12, respectively) over 2 years; the younger the age, the poorer the response. At each year of age from 4 to 12 years across the treatment groups, higher-concentration atropine showed a better treatment response, following a concentration-dependent effect (P_trend <0.05 for each age group). In addition, the mean SE progression in 6-year-old children receiving 0.05% atropine (-0.90 diopter [D]; 95% CI, -0.99 to -0.82) was similar to that of 8-year-old children receiving 0.025% atropine (-0.89 D; 95% CI, -0.94 to -0.83) and 10-year-old children receiving 0.01% atropine (-0.92 D; 95% CI, -0.99 to -0.85). All concentrations were well tolerated in all age groups.

CONCLUSIONS

Younger age is associated with poor treatment response to low-concentration atropine at 0.05%, 0.025%, and 0.01%. Among concentrations studied, younger children required the highest 0.05% concentration to achieve similar reduction in myopic progression as older children receiving lower concentrations.