The long-term results of using low-concentration atropine eye drops for controlling myopia progression in schoolchildren

Additive Effect of Highly Aspherical Lenslet Target Spectacles to Children Inadequately Controlled by Atropine Monotherapy

Purpose

Myopia progression in children, especially in East Asia, is a significant public health concern. This study evaluated the efficacy of combining myopia control spectacle lenses with Highly Aspherical Lenslet Target (HALT) technology and atropine in children who continued to progress on low-dose atropine (LDA).

Design

Prospective cohort.

Subjects

Children aged 6-11 years with ≥0.5 diopters (D) myopia progression over 6 months on LDA (0.01% or 0.025%) were recruited.

Methods

All participants used HALT (Essilor Stellest) spectacle lenses while maintaining their LDA dose. The changes in spherical equivalent (SE) and axial length (AL) were tracked for 6 months before and 6-12 months after starting combination treatment.

Main Outcome Measures

Progression of SE and AL.

Results

Fifty children (mean age 8.9 ± 1.1 years) were separated into group A (on 0.01% atropine daily, n20) and group B (on 0.01% atropine twice daily, n5 and 0.025% atropine nightly, n25). Most (86%) were ethnic Chinese. The baseline SE and AL showed no significant intergroup differences, with prior myopia progression (0.60D/0.24 mm) over 6 months. After adding HALT lenses, progression slowed to -0.06D/0.06 mm at 6 months and -0.15D/0.14 mm at 12 months. A hyperopic shift in AL was seen in 11 children (24%). However, the progression of >0.5D was noted in 20%, with 18% and 40% progressing by >0.3 mm and >0.15 mm, respectively. Univariate analysis suggested that children who progressed >0.10 mm over 6 months were more likely to be younger, whereas multivariate analysis suggested that change in AL was associated with smaller pupil size (possibly from poor compliance or absorption of atropine) at 6 months and younger age at 12 months, after controlling for sex, race, and baseline SE and AL. There were no complaints of glare, near, or peripheral blur in children after starting combination treatment.

Conclusions

The addition of HALT spectacle lenses significantly reduced myopia progression in children, aged 6-11 years, who were poorly controlled on LDA alone demonstrating a potential synergistic effect with LDA. These findings supported combination therapy for managing challenging myopia cases.

Financial Disclosures

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Topical review: Potential mechanisms of atropine for myopia control

SIGNIFICANCE

Atropine is effective at slowing myopia progression in children, but the mechanism of action by which it controls myopia remains unclear. This article is an evidenced-based review of potential receptor-based mechanisms by which atropine may act to slow the progression of myopia.The rising number of individuals with myopia worldwide and the association between myopia and vision-threatening ocular pathologies have made myopia control treatments one of the fastest growing areas of ophthalmic research. High-concentration atropine (1%) is the most effective treatment for slowing myopia progression to date; low concentrations of atropine (≤0.05%) appear partially effective and are currently being used to slow myopia progression in children. While significant progress has been made in the past few decades in understanding fundamental mechanisms by which atropine may control myopia, the precise characterization of how atropine works for myopia control remains incomplete. It is plausible that atropine slows myopia via its affinity to muscarinic receptors and influence on accommodation, but animal studies suggest that this is likely not the case. Other studies have shown that, in addition to muscarinic receptors, atropine can also bind, or affect the action of, dopamine, alpha-2-adrenergic, gamma-aminobutyric acid, and cytokine receptors in slowing myopia progression. This review summarizes atropine's effects on different receptor pathways of ocular tissues and discusses how these effects may or may not contribute to slowing myopia progression. Given the relatively broad array of receptor-based mechanisms implicated in atropine control of myopia, a single mode of action of atropine is unlikely; rather atropine may be exerting its myopia control effects directly or indirectly via several mechanisms at multiple levels of ocular tissues, all of which likely trigger the response in the same direction to inhibit eye growth and myopia progression.

Effectiveness of various atropine concentrations in myopia control for Asian children: a network meta-analysis

Objectives

To assess the effectiveness of various atropine concentrations in managing myopia among children in East, South, and Southeast Asia, and to determine the most effective concentration.

Methods

A systematic literature review was conducted using PubMed, Web of Science, Cochrane Library, and EMBASE. The search was limited to articles published up to 1 June 2024, and included studies in Chinese or English. Two researchers independently screened the literature, extracted relevant data, and assessed the data quality using the Revised Cochrane risk-of-bias 2 (RoB2) tool. A network meta-analysis was performed using Stata 14.2 software to compare the efficacy of different atropine concentrations in delaying myopia progression, measured by changes in refraction and axial length.

Results

The analysis included 39 studies with 7,712 participants, examining 10 atropine concentrations ranging from 0.005% to 1%. Forest plots indicated that five concentrations (0.01%, 0.02%, 0.025%, 0.05%, and 1%) were more effective than a placebo in controlling myopia progression. The cumulative ordination plot indicated that 0.05% atropine most effectively delayed refraction change, which the mean change per year was 0.62D, while 1% was superior in slowing axial length progression, which the mean change per year was -0.43 mm. Considering both measures, 1% atropine showed the highest efficacy which the mean changes per year were 0.56D in spherical equivalent refraction and -0.43 mm in axial length, followed by 0.05% and 0.125% atropine.

Conclusion

While 1% atropine demonstrated the highest efficacy in myopia control among East, South and Southeast Asian children, its use is not recommended due to increased adverse effects and a rapid rebound in myopia after cessation. Considering both efficacy and safety, 0.05% atropine is suggested as the optimal concentration for myopia management in this population.

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.

Myopia management algorithm. Annexe to the article titled Update and guidance on management of myopia. European Society of Ophthalmology in cooperation with International Myopia Institute

Myopia is becoming increasingly common in young generations all over the world, and it is predicted to become the most common cause of blindness and visual impairment in later life in the near future. Because myopia can cause serious complications and vision loss, it is critical to create and prescribe effective myopia treatment solutions that can help prevent or delay the onset and progression of myopia. The scientific understanding of myopia's causes, genetic background, environmental conditions, and various management techniques, including therapies to prevent or postpone its development and slow its progression, is rapidly expanding. However, some significant information gaps exist on this subject, making it difficult to develop an effective intervention plan. As with the creation of this present algorithm, a compromise is to work on best practices and reach consensus among a wide number of specialists. The quick rise in information regarding myopia management may be difficult for the busy eye care provider, but it necessitates a continuing need to evaluate new research and implement it into daily practice. To assist eye care providers in developing these strategies, an algorithm has been proposed that covers all aspects of myopia mitigation and management. The algorithm aims to provide practical assistance in choosing and developing an effective myopia management strategy tailored to the individual child. It incorporates the latest research findings and covers a wide range of modalities, from primary, secondary, and tertiary myopia prevention to interventions that reduce the progression of myopia.

Myopia Control: Are We Ready for an Evidence Based Approach?

INTRODUCTION

Myopia and its vision-threatening complications present a significant public health problem. This review aims to provide an updated overview of the multitude of known and emerging interventions to control myopia, including their potential effect, safety, and costs.

METHODS

A systematic literature search of three databases was conducted. Interventions were grouped into four categories: environmental/behavioral (outdoor time, near work), pharmacological (e.g., atropine), optical interventions (spectacles and contact lenses), and novel approaches such as red-light (RLRL) therapies. Review articles and original articles on randomized controlled trials (RCT) were selected.

RESULTS

From the initial 3224 retrieved records, 18 reviews and 41 original articles reporting results from RCTs were included. While there is more evidence supporting the efficacy of low-dose atropine and certain myopia-controlling contact lenses in slowing myopia progression, the evidence about the efficacy of the newer interventions, such as spectacle lenses (e.g., defocus incorporated multiple segments and highly aspheric lenslets) is more limited. Behavioral interventions, i.e., increased outdoor time, seem effective for preventing the onset of myopia if implemented successfully in schools and homes. While environmental interventions and spectacles are regarded as generally safe, pharmacological interventions, contact lenses, and RLRL may be associated with adverse effects. All interventions, except for behavioral change, are tied to moderate to high expenditures.

CONCLUSION

Our review suggests that myopia control interventions are recommended and prescribed on the basis of accessibility and clinical practice patterns, which vary widely around the world. Clinical trials indicate short- to medium-term efficacy in reducing myopia progression for various interventions, but none have demonstrated long-term effectiveness in preventing high myopia and potential complications in adulthood. There is an unmet need for a unified consensus for strategies that balance risk and effectiveness for these methods for personalized myopia management.

Myopia progression patterns among paediatric patients in a clinical setting

PURPOSE

This retrospective analysis of electronic medical record (EMR) data investigated the natural history of myopic progression in children from optometric practices in Ireland.

METHODS

The analysis was of myopic patients aged 7-17 with multiple visits and not prescribed myopia control treatment. Sex- and age-specific population centiles for annual myopic progression were derived by fitting a weighted cubic spline to empirical quantiles. These were compared to progression rates derived from control group data obtained from 17 randomised clinical trials (RCTs) for myopia. Linear mixed models (LMMs) were used to allow comparison of myopia progression rates against outputs from a predictive online calculator. Survival analysis was performed to determine the intervals at which a significant level of myopic progression was predicted to occur.

RESULTS

Myopia progression was highest in children aged 7 years (median: -0.67 D/year) and progressively slowed with increasing age (median: -0.18 D/year at age 17). Female sex (p < 0.001), a more myopic SER at baseline (p < 0.001) and younger age (p < 0.001) were all found to be predictive of faster myopic progression. Every RCT exhibited a mean progression higher than the median centile observed in the EMR data, while clinic-based studies more closely matched the median progression rates. The LMM predicted faster myopia progression for patients with higher baseline myopia levels, in keeping with previous studies, which was in contrast to an online calculator that predicted slower myopia progression for patients with higher baseline myopia. Survival analysis indicated that at a recall period of 12 months, myopia will have progressed in between 10% and 70% of children, depending upon age.

CONCLUSIONS

This study produced progression centiles of untreated myopic children, helping to define the natural history of untreated myopia. This will enable clinicians to better predict both refractive outcomes without treatment and monitor treatment efficacy, particularly in the absence of axial length data.

Real-world outcomes of low-dose atropine therapy on myopia progression in an Australian cohort during the COVID-19 pandemic

BACKGROUND

To report the outcomes of low-dose atropine (0.01% and 0.05%) for preventing myopia progression in a real-world Australian cohort during the COVID-19 pandemic.

METHODS

Records of children presenting with myopia, from January 2016 to 2022, were retrospectively reviewed at a comprehensive ophthalmic practice. Children who discontinued treatment, ages >18, and cases with hereditary conditions were excluded. The rate of progression of myopia after treatment with atropine was compared with historical data to evaluate the effectiveness of the regime.

RESULTS

One hundred and one children (mean baseline spherical equivalent [SphE] [-3.70 +/- 2.09 D] and axial length [AL] [24.59 +/- 1.00 mm]) were analysed. The mean age of the children was 10.4 +/- 2.89 years and 61% were females. The average follow-up time was 17.9 +/- 12.5 months. The mean rate of progression of AL and SphE on 0.01% atropine eyedrops was 0.219 +/- 0.35 mm and - 0.250 +/- 0.86 D/year, respectively. 68.1% of the children treated with 0.01% atropine were mild progressors (<0.5 D change/year). Non-responders when commenced on a higher dose of atropine (0.05%) experienced a 93% (p = 0.012) and 30% reduction in SphE and AL growth rate, respectively. Family history, higher myopia or younger age at baseline and shorter duration of treatment were associated with steeper progression (p < 0.01). Both doses were well tolerated.

CONCLUSIONS

Low-dose atropine was shown to be beneficial in a real-world clinical setting, despite interruptions to follow-ups secondary to COVID-19 pandemic. A 0.05% dose of atropine may be effective in cases where 0.01% was ineffective.

Establishing a method to estimate the effect of antimyopia management options on lifetime cost of myopia

BACKGROUND

Informed decisions on myopia management require an understanding of financial impact. We describe methodology for estimating lifetime myopia costs, with comparison across management options, using exemplars in Australia and China.

METHODS

We demonstrate a process for modelling lifetime costs of traditional myopia management (TMM=full, single-vision correction) and active myopia management (AMM) options with clinically meaningful treatment efficacy. Evidence-based, location-specific and ethnicity-specific progression data determined the likelihood of all possible refractive outcomes. Myopia care costs were collected from published sources and key informants. Refractive and ocular health decisions were based on standard clinical protocols that responded to the speed of progression, level of myopia, and associated risks of pathology and vision impairment. We used the progressions, costs, protocols and risks to estimate and compare lifetime cost of myopia under each scenario and tested the effect of 0%, 3% and 5% annual discounting, where discounting adjusts future costs to 2020 value.

RESULTS

Low-dose atropine, antimyopia spectacles, antimyopia multifocal soft contact lenses and orthokeratology met our AMM inclusion criteria. Lifetime cost for TMM with 3% discounting was US$7437 (CI US$4953 to US$10 740) in Australia and US$8006 (CI US$3026 to US$13 707) in China. The lowest lifetime cost options with 3% discounting were antimyopia spectacles (US$7280, CI US$5246 to US$9888) in Australia and low-dose atropine (US$4453, CI US$2136 to US$9115) in China.

CONCLUSIONS

Financial investment in AMM during childhood may be balanced or exceeded across a lifetime by reduced refractive progression, simpler lenses, and reduced risk of pathology and vision loss. Our methodology can be applied to estimate cost in comparable scenarios.

Parasympathetic and sympathetic control of emmetropization in chick

Emmetropization can be altered by temporal visual stimulation and the spectral properties of the visual environment. The goal of the current experiment is to test the hypothesis that there is an interaction between these properties and autonomic innervation. For that purpose, selective lesions of the autonomic nervous system were performed in chickens followed by temporal stimulation. Parasympathetic lesioning involved transection of both the ciliary ganglion and the pterygopalatine ganglion (PPG_CGX; n = 38), while sympathetic lesioning involved transection of the superior cervical ganglion (SCGX; n = 49). After one week of recovery, chicks were then exposed to temporally modulated light (3 days, 2 Hz, Mean: 680 lux) that was either achromatic (with blue [RGB], or without blue [RG]), or chromatic (with blue [B/Y] or without blue [R/G]). Control birds with lesions, or unlesioned, were exposed to white [RGB] or yellow [RG] light. Ocular biometry and refraction (Lenstar and a Hartinger refractometer) was measured before and after exposure to light stimulation. Measurements were statistically analyzed for the effects of a lack of autonomic input and the type of temporal stimulation. In PPG_CGX lesioned eyes, there was no effect of the lesions one-week post-surgery. However, after exposure to achromatic modulation, the lens thickened (with blue) and the choroid thickened (without blue) but there was no effect on axial growth. Chromatic modulation thinned the choroid with R/G. In the SGX lesioned eye, there was no effect of the lesion 1-week post-surgery. However, after exposure to achromatic modulation (without blue), the lens thickened and there was a reduction in vitreous chamber depth and axial length. Chromatic modulation caused a small increase in vitreous chamber depth with R/G. Both autonomic lesion and visual stimulation were necessary to affect the growth of ocular components. The bidirectional responses observed in axial growth and in choroidal changes suggest that autonomic innervation combined with spectral cues from longitudinal chromatic aberration may provide a mechanism for homeostatic control of emmetropization.

Effect of 0.02% and 0.01% atropine on ocular biometrics: A two-year clinical trial

BACKGROUND

Several studies have shown that various concentrations of low-concentration atropine can reduce myopia progression and control axial elongation safely and efficiently in children. The aim of this study was to evaluate the effects of 0.02% and 0.01% atropine on ocular biometrics.

METHODS

Cohort study. 138 and 142 children were randomized to use either 0.02% or 0.01% atropine eye drops, respectively. They wore single-vision (SV) spectacles, with one drop of atropine applied to both eyes nightly. Controls (N = 120) wore only SV spectacles. Ocular and corneal astigmatism were calculated using Thibos vector analysis and split into J0 and J45.

RESULTS

The changes in cycloplegic spherical equivalent refraction (SER) and axial length (AL) were -0.81 ± 0.52D, -0.94 ± 0.59D, and -1.33 ± 0.72D; and 0.62 ± 0.29 mm, 0.72 ± 0.31 mm, and 0.89 ± 0.35 mm in the 0.02% and 0.01% atropine and control groups, respectively (all P < 0.05). Both anterior chamber depth (ACD) and ocular astigmatism (including J0) increased, and lens power decreased in the three groups (all P < 0.05). However, there were no differences in the changes in ACD, ocular astigmatism, and lens power among the three groups (all P > 0.05). Intraocular pressure (IOP), corneal curvature, ocular astigmatism J45, and corneal astigmatism (including J0 and J45) remained stable over time in the three groups (all P > 0.05). The contributions to SER progression from the changes in AL, lens and corneal power of the three groups were similar (P > 0.05). The contribution of AL change alone to the change in SER was 56.3%, 63.4% and 78.2% in the above corresponding three groups.

CONCLUSIONS

After 2 years, 0.02% and 0.01% atropine had no clinical effects on corneal and lens power, ocular and corneal astigmatism, ACD or IOP compared to the control group. 0.02% and 0.01% atropine helped to control myopia progression mainly by reducing AL elongation.

Role of 0.01% atropine in high myopic children of Moradabad, India (RAMCOM Study)

Purpose

Low-concentration atropine is an emerging therapy for myopia progression, but its efficacy remains uncertain among high myopic children. This study aimed to evaluate the efficacy and safety of low-concentration atropine eye drop (0.01%) in high myopic children.

Methods

A non-randomized, parallel-group, longitudinal interventional cohort study. Myopic children were divided into two groups: (1) the intervention arm of children who received one drop of topical 0.01% atropine once a day at bedtime and (2) the control arm, in which enrolled children who were on observation only. Repeated measurements of spherical equivalent refractive errors (SERs) were performed at baseline and 1 and 2 years after treatment.

Results

A total of 37 eyes were enrolled in the intervention arm (allocated to 0.01% atropine at year 1 follow-up) and 23 eyes in the control arm. After 1 year of 0.01% atropine therapy, the myopia progression was 0.15 ± 0.9 D in the intervention group versus 1.1 ± 1 D in the control group (P = 0.001). Similarly, after 2 years of treatment, the myopia progression was 0.3 ± 1.1 D in the intervention group versus 1.4 ± 1.1 D in the control group (P ≤ 0.001).

Conclusion

Compared to no treatment, 0.01% atropine treatment had shown better effect on myopia progression in high myopic children.

Classification-Based Approaches to Myopia Control in a Taiwanese Cohort

Purpose

Myopia is a disorder of growing prevalence in school-aged children worldwide, especially in Asia. Although low-dose atropine is recognized as an effective treatment to slow myopia progression, different studies have reported varying efficacies of treatment, and the optimal concentration of low-dose atropine remains an open question.

Methods

A two-stage approach was conducted in this study. First, an observational study was conducted to plot the axial length growth curve for Taiwanese children. Second, an interventional 2-year study was performed in which different concentrations of low-dose atropine were applied based upon the risk-level status from the first stage.

Results

A total of 4,091 subjects, consisting of 2,105 boys (51.5%) and 1,986 girls (48.5%), were enrolled in the first stage to plot the axial growth curve for Taiwanese children aged between 3 and 16 years. The percentage of children with myopia increased from 2.3% in 4-year-olds to 88.0% in 16-year-olds. At the second stage, a total of 886 subjects [307 (34.65%) at low risk, 358 (40.41%) at moderate risk and 221 (24.94%) at high risk] were enrolled to receive low-dose atropine based upon the risk level (0.02, 0.03, and 0.05%, respectively). With this approach, the mean annual myopia progression was −0.33, −0.57, and −0.82 D in the low-risk, moderate-risk and high-risk groups, respectively. Applying annual myopic progression < -1.0 D as a criterion for responder, the responder rates were 95.77, 83.52, and 70.59% in the low-risk, moderate-risk, and high-risk groups, respectively.

Conclusions

We proposed a classification-based approach involving different concentrations of low-dose atropine based upon an individual's risk-level status. With this approach, myopic progression can be effectively controlled in patients without exposure to atropine side effects due to exposure to a higher dose than actually needed.

Characteristics of responders to atropine 0.01% as treatment in Asian myopic children

Recently, low-concentration atropine (0.01%) has gained increased attention in controlling myopia progression with satisfying effects and minimal side effects. However, studies concerning responders to 0.01% atropine are limited. This retrospective observational cohort study aimed to determine the responder characteristics of 0.01% atropine in Asian children. One hundred forty children (aged between 3 and 15 years) receiving 0.01% atropine were analyzed for the factors influencing annual spherical equivalent changes (SE). The mean age was 9.13 (2.6) years, the mean baseline SE was - 1.56 (1.52) diopters (D), and the mean annual SE change was - 0.52 (0.49) D. A 58.63% responder rate (146/249) of myopic control was achieved with 0.01% atropine in our entire cohort under the criteria of less than 0.5 D of myopic progression annually. The subjects were stratified into 4 subgroups based on a cut-off point of baseline SE of - 1.5 D and baseline age of 9 years. The responder rate differed significantly with the highest being the youngest with the lowest myopia subgroups. Our results demonstrated that children with myopia better than - 1.5 D and younger than 9 years had the highest potential to achieve successful myopic control under 0.01% atropine therapy.

The Association of Choroidal Thickening by Atropine With Treatment Effects for Myopia: Two-Year Clinical Trial of the Low-concentration Atropine for Myopia Progression (LAMP) Study

PURPOSE

To evaluate longitudinal changes in subfoveal choroidal thickness (SFChT) among children receiving atropine 0.05%, 0.025%, or 0.01% over 2 years and their associations with treatment outcomes in myopia control.

DESIGN

Double-blinded randomized controlled trial.

METHODS

SFChT was measured at 4-month intervals using spectral domain optical coherence tomography. Cycloplegic spherical equivalent (SE), axial length (AL), best-corrected visual acuity, parental SE, outdoor time, near work diopter hours, and treatment compliance were also measured.

RESULTS

314 children were included with qualified choroidal data. The 2-year changes in SFChT from baseline were 21.15 ± 32.99 µm, 3.34 ± 25.30 µm, and -0.30 ± 27.15 µm for the atropine 0.05%, 0.025%, and 0.01% groups, respectively (P < .001). A concentration-dependent response was observed, with thicker choroids at higher atropine concentrations (β = 0.89, P < .001). Mean SFChT thickness significantly increased at 4 months in the atropine 0.025% (P = .001) and 0.05% groups (P < .001) and then remained stable until the end of the second year (P > .05 for all groups). Over 2 years, an increase in SFChT was associated with slower SE progression (β = 0.074, P < .001) and reduced AL elongation (β = -0.045, P < .001). In the mediation analysis, 18.45% of the effect on SE progression from atropine 0.05% was mediated via its choroidal thickening.

CONCLUSIONS

Low concentration atropine induced a choroidal thickening effect along a concentration-dependent response throughout the treatment period. The choroidal thickening was associated with a slower SE progression and AL elongation among all the treatment groups. Choroidal response can be used for assessment of long-term treatment outcomes and as a guide for concentration titrations of atropine.

The Limited Value of Prior Change in Predicting Future Progression of Juvenile-onset Myopia

SIGNIFICANCE

Identifying children at highest risk for rapid myopia progression and/or rapid axial elongation could help prioritize who should receive clinical treatment or be enrolled in randomized clinical trials. Our models suggest that these goals are difficult to accomplish.

PURPOSE

This study aimed to develop models predicting future refractive error and axial length using children's baseline data and history of myopia progression and axial elongation.

METHODS

Models predicting refractive error and axial length were created using randomly assigned training and test data sets from 916 myopic participants in the Collaborative Longitudinal Evaluation of Ethnicity and Refractive Error Study. Subjects were 7 to 14 years of age at study entry with three consecutive annual visits that included cycloplegic A-scan ultrasound and autorefraction. The effect of adding prior change in axial length and refractive error was evaluated for each model.

RESULTS

Age, ethnicity, and greater myopia were significant predictors of future refractive error and axial length, whereas prior progression or elongation, near work, time outdoors, and parental myopia were not. The 95% limits for the difference between actual and predicted change were ±0.22 D and ±0.14 mm without prior change data compared with ±0.26 D and ±0.16 mm with prior change data. Sensitivity and specificity for identifying fast progressors were between 60.8 and 63.2%, respectively, when the cut points were close to the sample average. Positive predictive value and sample yield were even lower when the cut points were more extreme.

CONCLUSIONS

Young, more myopic Asian American children in the Collaborative Longitudinal Evaluation of Ethnicity and Refractive Error Study were the most likely to progress rapidly. Clinical trials should expect average progression rates that reflect sample demographics and may have difficulty recruiting generalizable samples that progress faster than that average. Knowing progression or elongation history does not seem to help the clinical decision regarding initiating myopia control.

The Role of Atropine in Preventing Myopia Progression: An Update

Several approaches have been investigated for preventing myopia progression in children and teenagers. Among them, topical atropine has shown promising results and it is being adopted in clinical practice more and more frequently. However, the optimal formulation and treatment algorithm are still to be determined. We discuss the pharmacokinetic, pharmacodynamic, clinical, and tolerability profile revealed first by the multicenter, randomized ATOM 1 and 2 trials and, more recently, by the LAMP Study. Results from these trials confirmed the efficacy of low-concentration atropine with a concentration-dependent response. Although atropine at 0.025% and 0.05% concentrations has shown the most encouraging results in large-scale studies, these formulations are not yet commonplace in worldwide clinical practice. Moreover, their rebound effect and the possibility of reaching a stabilization effect have not been fully investigated with real-life studies. Thus, further larger-scale studies should better characterize the clinical efficacy of atropine over longer follow-up periods, in order to define the optimal dosage and treatment regimen.

Effect of 0.02% and 0.01% atropine on astigmatism: a two-year clinical trial

Background

To evaluate the effects of 0.02% and 0.01% atropine eye drops on ocular and corneal astigmatism over 2 years.

Methods

A prospective clinic-controlled trail. The cohort study assessed 400 myopic children and divided them into three groups: 138 and 142 children were randomized to use either 0.02% or 0.01% atropine eye drops, respectively. They wore single-vision (SV) spectacles, with one drop of atropine applied to both eyes once nightly. Control children (n = 120) only wore SV spectacles. Spherical equivalent refractive errors (SER) and corneal curvature were measured every 4 months. The SER and corneal curvature were assessed by cycloplegic autorefraction and IOLMaster. Ocular and corneal astigmatism were calculated by Thibos vector analysis and then split into its power vector components, J0 (with-the-rule astigmatism) and J45 (oblique).

Results

After 2 years, the ocular astigmatism increased by -0.38 ± 0.29 D, -0.47 ± 0.38 D, -0.41 ± 0.35 D in the 0.02%, 0.01% atropine groups and control group, respectively (p = 0.15). The corresponding corneal astigmatism increased by -0.20 ± 0.34 D, -0.28 ± 0.35 D and -0.26 ± 0.26 D (p = 0.18). The ocular astigmatism J0 increased by 0.19 ± 0.28 D, 0.22 ± 0.36 D, 0.18 ± 0.31 D in the 0.02% atropine, 0.01% atropine and control groups, respectively (p = 0.65). The corresponding corneal astigmatism J0 increased by -0.05 ± 0.34 D, -0.11 ± 0.37 D and -0.13 ± 0.30 D (p = 0.23). There was a small but significant increase in ocular astigmatism (including J0) (all P < 0.05), but there were no changes in the ocular astigmatism J45 and corneal astigmatism (including J0 and J45) in the three groups over time (all p > 0.05). However, there were no significant differences in the changes in ocular astigmatism (including J0) among the three groups.

Conclusions

Treatment with 0.02% and 0.01% atropine had no clinically significant effect on ocular and corneal astigmatism over 2 years.

Trial registration

The First Affiliated Hospital of Zhengzhou University, ChiCTR-IPD-16008844. Registered 14/07/2016.

Parasympathetic innervation of emmetropization

Emmetropization is affected by the temporal parameters of visual stimulation and the spectral composition of light, as well as by autonomic innervation. The goal of the current experiments is to test the hypothesis that different types of visual stimulation interact with ocular innervation in the process of emmetropization. For that, selective lesions of the autonomic nervous system were performed in chickens: involving transection of parasympathetic input to the eye from either the ciliary ganglion, innervating accommodation and pupil responses (CGX; n = 32), or pterygopalatine ganglion, innervating choroidal blood vessels and cornea (PPGX; n = 26). After 1 week of recovery, chicks were exposed to sinusoidally modulated light (3 days, 2 Hz, 680 lux) that was either achromatic (black to white [RGB], or black to yellow [RG]), or chromatic (blue to yellow [B/Y] or red to green [R/G]). Exposure to light stimulation was followed by ocular biometry (Lenstar and a Hartinger refractometer). Surgical conditions revealed a small reduction in anterior chamber depth with CGX but no other significant changes in ocular biometry/refraction under standard light conditions. With RGB achromatic stimulation, CGX eyes produced an effect on ocular components, with a further reduction in anterior chamber depth and an increase in vitreous chamber depth, while RG stimulation showed no effect. No effect was detected in PPGX under both achromatic protocols. With chromatic stimulation, CGX with R/G modulation increased eye length, while PPGX with B/Y modulation decreased eye length. We conclude that the two different types of parasympathetic innervations have antagonistic effects on eye growth and the anterior eye when challenged with the appropriate stimulus, with possible implications for the role of choroidal blood flow in emmetropization.

Varying Dose of Atropine in Slowing Myopia Progression in Children Over Different Follow-Up Periods by Meta-Analysis

Purpose: To evaluate the efficacy and safety of atropine for slowing myopia progression and to investigate whether the treatment effect remains constant with continuing treatment.

Method: Studies were retrieved from MEDLINE, EMBASE, and the Cochrane Library from their inception to May 2021, and the language was limited to English. Randomized controlled trials (RCTs) and cohort studies involving atropine in at least one intervention and placebo/non-atropine treatment in another as the control were included and subgroup analysis based on low dose (0.01%), moderate dose (0.01%–<0.5%), and high dose (0.5–1.0%) were conducted. The Cochrane Collaboration and Newcastle-Ottawa Scale were used to evaluate the quality of RCTs and cohort studies, respectively.

Results: Twelve RCTs and fifteen cohort studies involving 5,069 children aged 5 to 15 years were included. The weighted mean differences in myopia progression between the atropine and control groups were 0.73 diopters (D), 0.67 D, and 0.35 D per year for high-dose, moderate-dose, and low-dose atropine, respectively (χ² = 13.76; P = 0.001, I² = 85.5%). After removing studies that provided extreme findings, atropine demonstrated a significant dose-dependent effect on both refractive change and axial elongation, with higher dosages of atropine resulting in less myopia progression (r = 0.85; P = 0.004) and less axial elongation (r = −0.94; P = 0.005). Low-dose atropine showed less myopia progression (−0.23 D; P = 0.005) and less axial elongation (0.09 mm, P < 0.001) in the second year than in the first year, whereas in high-dose atropine more axial elongation (−0.15 mm, P = 0.003) was observed. The higher dose of atropine was associated with a higher incidence of adverse effects, such as photophobia with an odds ratio (OR) of 163.57, compared with an OR of 6.04 for low-dose atropine and 8.63 for moderate-dose atropine (P = 0.03).

Conclusion: Both the efficacy and adverse effects of atropine are dose-dependent in slowing myopia progression in children. The efficacy of high-dose atropine was reduced after the first year of treatment, whereas low-dose atropine had better efficacy in a longer follow-up period.

Predicting factors for progression of the myopia in the MiSight assessment study Spain (MASS)

PURPOSE

To investigate which baseline factors are predictive for success in controlling myopia progression in a group of children wearing MiSight Contact Lens (CLs).

METHODS

Myopic patients (n=41) fitted with MiSight CLs and followed up two years were included in this study. Bivariate analysis, a logistic regression analysis (LG) and a decision tree (DT) approach were used to screen for the factors influencing the success of the treatment. To assess the response, axial length (AL) changes were considered as main variable. Patients were classified based on a specific range of change of axial length at the end of each year of treatment as "responders" (R) (AL change <0.11mm/per year) and "non-responders" (NR) (AL change ≥0.11mm/per year).

RESULTS

Of a total of forty-one Caucasian patients treated with MiSight CLs, 21 and 16 were considered responders in the first and the second year of follow-up, respectively. LG analysis showed that the only factor associated with smaller axial length growth was more time spent outdoors (p=0.0079) in the first year of treatment. The decision tree analysis showed that in the responding group spending more than 3 and 4h outdoors per week was associated with the best response in the first year and in the second year of treatment respectively.

CONCLUSIONS

The LR and the DT approach of this pilot study identifies time spent outdoors as a main factor in controlling axial eye growth in children treated with MiSight CLs.

Orthokeratology Lenses Versus Administration of 0.01% Atropine Eye Drops for Axial Length Elongation in Children With Myopic Anisometropia

OBJECTIVE

To investigate the effect of orthokeratology (OK) lenses and that of 0.01% atropine eye drops on axial length (AL) elongation in children with myopic anisometropia.

METHODS

Ninety-five children with myopic anisometropia who used OK lenses (N=49) or 0.01% atropine eye drops (N=46) were enrolled in this retrospective 1-year study. For all children, the eyes with higher spherical equivalent refractive error (SER) were assigned to the H-eye subgroup, whereas the fellow eyes with lower SER were assigned to the L-eye subgroup.

RESULTS

After 1-year treatment, the mean change in the AL of H eyes and L eyes in the OK lenses group was 0.18±0.16 mm and 0.24±0.15 mm, respectively (P=0.15), and 0.28±0.20 mm and 0.25±0.18 mm, respectively (P=0.48), in the 0.01% atropine group. Multivariate regression analyses showed significant differences in AL change between H and L eyes after treatment with OK lens (P=0.03), whereas no significant difference in the 0.01% atropine (P=0.22). The change in the AL in the H-eye group was less with OK lenses than with 0.01% atropine (P=0.04), whereas there was no significant difference between the change in AL in the L-eye group between treatment with OK lens and 0.01% atropine (P=0.89).

CONCLUSIONS

In myopic anisometropic children, AL differences between 2 eyes decrease by wearing OK lenses but do not change after administration of 0.01% atropine eye drops. The increased effect of OK lenses, but not 0.01% atropine, in reducing axial elongation at 1 year in the eye with higher SER in anisometropic children warrants further investigation.

Changes in visual cortical function in moderately myopic patients: a functional near-infrared spectroscopy study

PURPOSE

To investigate haemoglobin oxygenation in the visual cortex of myopic patients using functional near-infrared spectroscopy (fNIRS).

METHODS

The experiment consisted of two parts. Part 1 examined functional changes in the visual cortex before and after refractive correction in myopic patients. Subjects were divided into normal controls, uncorrected and corrected myopes. Part 2 examined functional changes in the visual cortex caused by lens-induced myopia in normal subjects, and whether this activity recovered after a period of rest. Here, subjects were divided into three groups: emmetropes, lens-induced myopia and a rest group. The rest group completed a test with the uncorrected eye following lens removal and 5 min of rest. The visual stimulus was a black and white checkerboard. fNIRS was used to detect changes in oxyhaemoglobin content within the visual cortex. The original fNIRS data were analysed using MATLAB to obtain the β values (the visual cortical activity response caused by the task); these were used to calculate Δβ, which represents the degree of change in oxygenated haemoglobin caused by visual stimulation.

RESULTS

The Δβ value measured in each single channel or only in the region of interest (ROI) was significantly higher in the emmetropic control group than the uncorrected myopic group. After optical correction, the responses of myopic subjects approached those of the emmetropes and were not significantly different. If myopia was induced in emmetropic subjects by imposing defocus with positive lenses, a decline in functional activity was observed similar that observed in uncorrected myopes. Activity recovered after the lenses were removed.

CONCLUSIONS

Myopic defocus reduced the level of haemoglobin oxygenation in the visual cortex, but activity could be restored by optical correction.

Stepwise low concentration atropine for myopic control: a 10-year cohort study

The aim of this study was to analyze changes in refraction and evaluate the variables in school children who received atropine as myopic control for 10 years. Low-concentration atropine (0.05%) was prescribed initially, and the dose was increased in a stepwise manner if rapid myopic progression (≥ 0.5D per half year) was noted during the regular follow-up visit. 23 children with a mean age of 6.96 ± 1.07 years were included. The initial spherical equivalent was − 1.25 ± 0.84 D. The overall mean myopic progression was − 0.30 ± 0.27 D/year. Younger initial age, female, higher initial spherical equivalent and the need of higher concentration of atropine were found to be risk factors for myopic progression in multivariate mixed-effect analysis (p = 0.013, 0.017, 0.024 and 0.014). Children who kept using a lower concentration of atropine (≤ 0.1%) tended to have slower myopic progression throughout the 10-year course than those who shifted to higher concentrations (> 0.1%) (p ≤ 0.001). Stepwise low concentration of atropine might be effective for long-term myopic control in school students. Those who had poor response to lower concentration of atropine may have the risk of faster progression, even with high concentration of atropine. Additional or alternative treatment might be considered.

Use baseline axial length measurements in myopic patients to predict the control of myopia with and without atropine 0.01

PURPOSE

Identifying axial length growth rate as an indicator of fast progression before initiating atropine 0.01% for myopia progression in children.

METHOD

From baseline, axial length growth over six months was measured prospectively. Subjects were then initiated on atropine 0.01% if axial length growth was greater than 0.1mm per 6 months (fast progressors), axial length and spherical equivalent change measurements recorded every six months. The rate of change was compared to the baseline pre-treatment rate. If axial length change was below the threshold, subjects received monitoring only.

RESULTS

73 subjects were identified as fast progressors and commenced atropine 0.01%, (mean baseline refraction of OD -2.9±1.6, OS -2.9±1.8 and a mean baseline axial length OD 24.62 ± 1.00 mm, OS 24.53 ± 0.99 mm). At six months, the mean paired difference of axial length growth rate was significantly reduced by 50% of baseline (all 73 subjects, p<0.05). 53 subjects followed to 12 months, and 12 to 24 months maintained a reduced growth rate. Change in mean spherical equivalent was significantly reduced compared to pre-treatment refractive error (mean paired difference p<0.05) and at each subsequent visit. 91 children were slow progressors and remained untreated. Their axial length growth rate did not change significantly out to 24 months. Spherical equivalent changed less than -0.5D annually in this group.

CONCLUSION

Identifying fast progressors before treatment initiation demonstrated a strong treatment effect with atropine 0.01% reducing their individual rate of myopia progression by 50%. Another large group of myopic children, slow progressors, continued without medical intervention. A baseline axial length growth rate is proposed as a guideline to identify fast progressors who are more likely to benefit from atropine 0.01%.

Risk factors for rapid axial length elongation with low concentration atropine for myopia control

Three hundred and twenty-eight myopic children, randomized to use either 0.01% (N = 166) or 0.02% (N = 162) atropine were enrolled in this study. Gender, age, body mass index(BMI), parental myopia status, atropine concentration used, pupil diameter, amplitude of accommodation, spherical equivalent refractive error (SER), anterior chamber depth (ACD) and axial length (AL) were collected at baseline and 1 year after using atropine. Rapid AL elongation was defined as > 0.36 mm growth per year. Univariate analyses showed that children with rapid AL elongation tend to be younger, have a smaller BMI, use of 0.01% atropine, narrow ACD, lower SER, shorter AL, smaller change in pupil diameter between 1 year and baseline (all P < 0.05). Multivariate logistic regression analyses confirmed that rapid AL elongation was associated with children that were younger at baseline (P < 0.0001), use of 0.01% atropine (P = 0.04), a shorter baseline AL (P = 0.03) and a smaller change in pupil diameter between 1 year and baseline (P = 0.04). Younger children with shorter AL at baseline, less change in their pupil diameter with atropine treatment and using the lower of the two atropine concentrations may undergo rapid AL elongation over a 12 months myopia control treatment period.

Effects of Atropine Treatment on Choroidal Thickness in Myopic Children

Purpose

To examine the changes in choroidal thickness (ChT) after 6 months of 1% or 0.01% atropine treatment and the independent factors associated with eye elongation.

Methods

A total of 207 myopic children aged 6 to 12 years were recruited and randomly assigned to groups A and B in a ratio of 1:1. Participants in group A received 1% atropine once a day for 1 week, and then once a week for 23 weeks. Participants in group B received 0.01% atropine once a day for 6 months. ChT and internal axial length (IAL) were measured at baseline, 1 week, 3 months, and 6 months.

Results

In group A, the ChT significantly increased after a 1-week loading dose of 1% atropine (26 ± 14 µm; P < 0.001) and the magnitude of increase stabilized throughout the following weekly treatment. The internal axial length did not significantly change at the 6-month visit (−0.01 ± 0.11 mm; P = 0.74). In contrast, a decreased ChT (−5 ± 17 µm; P < 0.001) and pronounced eye elongation (0.19 ± 0.12 mm; P < 0.001) were observed in group B after 6 months. Multivariable regression analysis showed that less increase in ChT at the 1-week visit (P = 0.03), younger age (P < 0.001), and presence of peripapillary atrophy (P = 0.001) were significantly associated with greater internal axial length increase over 6 months in group A.

Conclusions

One percent atropine could increase the ChT, whereas 0.01% atropine caused a decrease in ChT after 6 months of treatment. For participants receiving 1% atropine, the short-term increase in ChT was negatively associated with long-term eye elongation. Younger age and the presence of peripapillary atrophy were found to be risk factors for greater eye elongation.

Update and guidance on management of myopia. European Society of Ophthalmology in cooperation with International Myopia Institute

The prevalence of myopia is increasing extensively worldwide. The number of people with myopia in 2020 is predicted to be 2.6 billion globally, which is expected to rise up to 4.9 billion by 2050, unless preventive actions and interventions are taken. The number of individuals with high myopia is also increasing substantially and pathological myopia is predicted to become the most common cause of irreversible vision impairment and blindness worldwide and also in Europe. These prevalence estimates indicate the importance of reducing the burden of myopia by means of myopia control interventions to prevent myopia onset and to slow down myopia progression. Due to the urgency of the situation, the European Society of Ophthalmology decided to publish this update of the current information and guidance on management of myopia. The pathogenesis and genetics of myopia are also summarized and epidemiology, risk factors, preventive and treatment options are discussed in details.

Biological Mechanisms of Atropine Control of Myopia

Myopia is a global problem that is increasing at an epidemic rate in the world. Although the refractive error can be corrected easily, myopes, particularly those with high myopia, are susceptible to potentially blinding eye diseases later in life. Despite a plethora of myopia research, the molecular/cellular mechanisms underlying the development of myopia are not well understood, preventing the search for the most effective pharmacological control. Consequently, several approaches to slowing down myopia progression in the actively growing eyes of children have been underway. So far, atropine, an anticholinergic blocking agent, has been most effective and is used by clinicians in off-label ways for myopia control. Although the exact mechanisms of its action remain elusive and debatable, atropine encompasses a complex interplay with receptors on different ocular tissues at multiple levels and, hence, can be categorized as a shotgun approach to myopia treatment. This review will provide a brief overview of the biological mechanisms implicated in mediating the effects of atropine in myopia control.

Comparison of Administration of 0.02% Atropine and Orthokeratology for Myopia Control

OBJECTIVE

To compare the efficacies of 0.02% atropine eye drops and orthokeratology to control axial length (AL) elongation in children with myopia.

METHODS

In this historical control study, 247 children with myopia whose administration of 0.02% atropine (n=142) or underwent orthokeratology from an earlier study (n=105, control group) were enrolled. Data on AL and other baseline parameters were recorded at baseline and after 1 and 2 years of treatment.

RESULTS

The mean changes in AL in the first and second years of treatment were 0.30±0.21 and 0.28±0.20 mm, respectively, in the 0.02% atropine group and 0.16±0.20 and 0.20±0.16 mm, respectively, in the orthokeratology group. Axial length elongations after 2 years of treatment were 0.58±0.35 and 0.36±0.30 mm (P=0.007) in the 0.02% atropine and orthokeratology groups, respectively. Multivariate regression analyses showed that the AL elongation was significantly faster in the 0.02% atropine group than in the orthokeratology group (β=0.18, P=0.009). In multivariate regression analyses, younger age and shorter baseline AL were associated with a rapid AL elongation in the 0.02% atropine group (βage=-0.04, P=0.01; βAL=-0.17, P=0.03), while younger age, lower baseline spherical equivalent refractive error (SER), and shorter baseline AL were associated with a greater increase in AL in the orthokeratology group (βage=-0.03, P=0.04; βSER=0.06, P=0.03; βAL=-0.11, P=0.009). Faster AL elongation was found in the 0.02% atropine group compared with the orthokeratology group at higher baseline SER (P=0.04, interaction test).

CONCLUSION

Within the limits of this study design, orthokeratology seems to be a better method for controlling AL elongation compared with administration of 0.02% atropine in children with higher myopia over a treatment period of 2 years.

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.

Pharmacotherapeutic candidates for myopia: A review

This review provides insights into the mechanism underlying the pathogenesis of myopia and potential targets for clinical intervention. Although the etiology of myopia involves both environmental and genetic factors, recent evidence has suggested that the prevalence and severity of myopia appears to be affected more by environmental factors. Current pharmacotherapeutics are aimed at inhibiting environmentally induced changes in visual input and subsequent changes in signaling pathways during myopia pathogenesis and progression. Recent studies on animal models of myopia have revealed specific molecules potentially involved in the regulation of eye development. Among them, the dopamine receptor plays a critical role in controlling myopia. Subsequent studies have reported pharmacotherapeutic treatments to control myopia progression. In particular, atropine treatment yielded favorable outcomes and has been extensively used; however, current studies are aimed at optimizing its efficacy and confirming its safety. Furthermore, future studies are required to assess the efficacy of combinatorial use of low-dose atropine and contact lenses or orthokeratology.

Reducing the Global Burden of Myopia by Delaying the Onset of Myopia and Reducing Myopic Progression in Children: The Academy's Task Force on Myopia

In 2019, the American Academy of Ophthalmology (AAO) created the Task Force on Myopia in recognition of the substantial global increases in myopia prevalence and its associated complications. The Task Force, led by Richard L. Abbott, MD, and Donald Tan, MD, comprised recognized experts in myopia prevention and treatment, public health experts from around the world, and organization representatives from the American Academy of Family Physicians, American Academy of Optometry, and American Academy of Pediatrics. The Academy's Board of Trustees believes that myopia is a high-priority cause of visual impairment, warranting a timely evaluation and synthesis of the scientific literature and formulation of an action plan to address the issue from different perspectives. This includes education of physicians and other health care providers, patients and their families, schools, and local and national public health agencies; defining health policies to ameliorate patients' access to appropriate therapy and to promote effective public health interventions; and fostering promising avenues of research.

Annual Myopia Progression and Subsequent 2-Year Myopia Progression in Singaporean Children

Purpose

To investigate the association between 1-year myopia progression and subsequent 2-year myopia progression among myopic children in the Singapore Cohort Study of the Risk Factors for Myopia.

Methods

This retrospective analysis included 618 myopic children (329 male), 7 to 9 years of age (mean age, 8.0 ± 0.8) at baseline with at least two annual follow-up visits. Cycloplegic autorefraction was performed at every visit. Receiver operating characteristic (ROC) curves from multiple logistic regressions were derived for future fast 2-year myopia progression.

Results

Children with slow progression during the first year (slower than -0.50 diopter [D]/y) had the slowest mean subsequent 2-year myopia progression (-0.41 ± 0.33 D/y), whereas children with fast progression (faster than -1.25 D/y) in year 1 had the fastest mean subsequent 2-year myopia progression (-0.82 ± 0.30 D/y) (P for trend < 0.001). Year 1 myopia progression had the highest area under the curve (AUC) for predicting fast subsequent 2-year myopia progression (AUC = 0.77; 95% confidence interval [CI], 0.73-0.80) compared to baseline spherical equivalent (AUC = 0.70; 95% CI, 0.66-0.74) or age of myopia onset (AUC = 0.66; 95% CI, 0.61-0.70) after adjusting for confounders. Age at baseline alone had an AUC of 0.65 (95% CI, 0.61-0.69).

Conclusions

One-year myopia progression and age at baseline were associated with subsequent 2-year myopia progression in children 7 to 9 years of age.

Translational Relevance

Myopia progression and age at baseline may be considered by eye care practitioners as two of several factors that may be associated with future myopia progression in children.

A comparative study of orthokeratology and low-dose atropine for the treatment of anisomyopia in children

Myopic anisometropia (anisomyopia) is a specific type of refractive error that may cause fusion impairment, asthenopia, and aniseikonia. It is sometimes severe enough to reduce the quality of life. Several studies have investigated the treatment effects of orthokeratology (Ortho-K) and topical atropine on anisomyopia control. However, no study has compared these two interventions simultaneously until now. The cohort of this retrospective study included 124 children with anisomyopia who were treated with binocular Ortho-K lenses, 0.01% atropine, or 0.05% atropine. After a 2-year follow-up, the inter-eye difference in axial length (AL) significantly decreased in the Ortho-K group (P = 0.015) and remained stable in the two atropine groups. When comparing the myopia control effect, the use of Ortho-K lenses resulted in an obviously smaller change in AL than the use of 0.01% and 0.05% atropine (P < 0.01). Ortho-K treatment may reduce the degree of anisomyopia and stabilise the progression of myopia. Hence, Ortho-K might be a better choice for anisomyopic children.

Pathogenesis and Prevention of Worsening Axial Elongation in Pathological Myopia

PURPOSE

This review discusses the etiology and pathogenesis of myopia, prevention of disease progression and worsening axial elongation, and emerging myopia treatment modalities.

INTRODUCTION

Pediatric myopia is a public health concern that impacts young children worldwide and is associated with numerous future ocular diseases such as cataract, glaucoma, retinal detachment and other chorioretinal abnormalities. While the exact mechanism of myopia of the human eye remains obscure, several studies have reported on the role of environmental and genetic factors in the disease development.

METHODS

A review of literature was conducted. PubMed and Medline were searched for combinations and derivatives of the keywords including, but not limited to, "pediatric myopia", "axial elongation", "scleral remodeling" or "atropine." The PubMed and Medline database search were performed for randomized control trials, systematic reviews and meta-analyses using the same keyword combinations.

RESULTS

Studies have reported that detection of genetic correlations and modification of environmental influences may have a significant impact in myopia progression, axial elongation and future myopic ocular complications. The conventional pharmacotherapy of pediatric myopia addresses the improvement in visual acuity and prevention of amblyopia but does not affect axial elongation or myopia progression. Several studies have published varying treatments, including optical, pharmacological and surgical management, which show great promise for a more precise control of myopia and preservation of ocular health.

DISCUSSION

Understanding the role of factors influencing the onset and progression of pediatric myopia will facilitate the development of successful treatments, reduction of disease burden, arrest of progression and improvement in future of the management of myopia.

Two-Year Clinical Trial of the Low-Concentration Atropine for Myopia Progression (LAMP) Study: Phase 2 Report

PURPOSE

To evaluate the efficacy and safety of 0.05%, 0.025%, and 0.01% atropine eye drops over 2 years to determine which is the optimal concentration for longer-term myopia control.

DESIGN

Randomized, double-masked trial extended from the Low-Concentration Atropine for Myopia Progression (LAMP) Study.

PARTICIPANTS

Three hundred eighty-three of 438 children (87%) aged 4 to 12 years with myopia of at least -1.0 diopter (D) originally randomized to receive atropine 0.05%, 0.025%, 0.01%, or placebo once daily in both eyes in the LAMP phase 1 study were continued in this extended trial (phase 2).

METHODS

Children in the placebo group (phase 1) were switched to receive 0.05% atropine from the beginning of the second-year follow-up, whereas those in the 0.05%, 0.025%, and 0.01% atropine groups continued with the same regimen. Cycloplegic refraction, axial length (AL), accommodation amplitude, photopic and mesopic pupil diameter, and best-corrected visual acuity were measured at 4-month intervals.

MAIN OUTCOME MEASURES

Changes in spherical equivalent (SE) and AL and their differences between groups.

RESULTS

Over the 2-year period, the mean SE progression was 0.55±0.86 D, 0.85±0.73 D, and 1.12±0.85 D in the 0.05%, 0.025%, and 0.01% atropine groups, respectively (P = 0.015, P < 0.001, and P = 0.02, respectively, for pairwise comparisons), with mean AL changes over 2 years of 0.39±0.35 mm, 0.50±0.33 mm, and 0.59±0.38 mm (P = 0.04, P < 0.001, and P = 0.10, respectively). Compared with the first year, the second-year efficacy of 0.05% and 0.025% atropine remained similar (P >0.1), but improved mildly in the 0.01% atropine group (P = 0.04). For the phase 1 placebo group, the myopia progression was reduced significantly after switching to 0.05% atropine (SE change, 0.18 D in second year vs. 0.82 D in first year [P < 0.001]; AL elongated 0.15 mm in second year vs. 0.43 mm in first year [P < 0.001]). Accommodation loss and change in pupil size in all concentrations remained similar to the first-year results and were well tolerated. Visual acuity and vision-related quality of life remained unaffected.

CONCLUSIONS

Over 2 years, the efficacy of 0.05% atropine observed was double that observed with 0.01% atropine, and it remained the optimal concentration among the studied atropine concentrations in slowing myopia progression.

IMI - Interventions Myopia Institute: Interventions for Controlling Myopia Onset and Progression Report

Myopia has been predicted to affect approximately 50% of the world's population based on trending myopia prevalence figures. Critical to minimizing the associated adverse visual consequences of complicating ocular pathologies are interventions to prevent or delay the onset of myopia, slow its progression, and to address the problem of mechanical instability of highly myopic eyes. Although treatment approaches are growing in number, evidence of treatment efficacy is variable. This article reviews research behind such interventions under four categories: optical, pharmacological, environmental (behavioral), and surgical. In summarizing the evidence of efficacy, results from randomized controlled trials have been given most weight, although such data are very limited for some treatments. The overall conclusion of this review is that there are multiple avenues for intervention worthy of exploration in all categories, although in the case of optical, pharmacological, and behavioral interventions for preventing or slowing progression of myopia, treatment efficacy at an individual level appears quite variable, with no one treatment being 100% effective in all patients. Further research is critical to understanding the factors underlying such variability and underlying mechanisms, to guide recommendations for combined treatments. There is also room for research into novel treatment options.

[Treatment options for progressive myopia in childhood]

The incidence of myopia is increasing worldwide. The associated increase in secondary and vision-threatening eye diseases will pose major challenges to patients, ophthalmologists, optometrists, opticians and healthcare systems. Since myopia begins in childhood and adolescence, progression can only be influenced in this phase of life. This article gives an overview of optical and pharmacological treatment options, which show average effect sizes of up to 50% progression reduction with a comparatively favorable side effect profile.

The penetration and distribution of topical atropine in animal ocular tissues

PURPOSE

To conduct a multi-tissue investigation on the penetration and distribution of topical atropine in myopia treatment, and determine if atropine is detectable in the untreated contralateral eye after uniocular instillation.

METHODS

Nine mature New Zealand white rabbits were evenly divided into three groups. Each group was killed at 5, 24 and 72 hr, respectively, following uniocular instillation of 0.05 ml of 1% atropine. Tissues were sampled after enucleation: conjunctiva, sclera, cornea, iris, ciliary body, lens, retina, aqueous, and vitreous humors. The assay for atropine was performed using liquid chromatography-mass spectrometry (LC-MS), and molecular tissue distribution was illustrated using matrix-assisted laser desorption ionization-imaging mass spectrometry (MALDI-IMS) via an independent experiment on murine eyes.

RESULTS

At 5 hr, the highest (mean ± SEM) concentration of atropine was detected in the conjunctiva (19.05 ± 5.57 ng/mg, p < 0.05) with a concentration gradient established anteriorly to posteriorly, as supported by MALDI-IMS. At 24 hr, preferential binding of atropine to posterior ocular tissues occurred, demonstrating a reversal of the initial concentration gradient. Atropine has good ocular bioavailability with concentrations of two magnitudes higher than its binding affinity in most tissues at 3 days. Crossing-over of atropine to the untreated eye occurred within 5 hr post-administration.

CONCLUSION

Both transcorneal and transconjunctival-scleral routes are key in atropine absorption. Posterior ocular tissues could be important sites of action by atropine in myopic reduction. In uniocular atropine trials, cross-over effects on the placebo eye should be adjusted to enhance results reliability. Combining the use of LC-MS and MALDI-IMS can be a viable approach in the study of the ocular pharmacokinetics of atropine.

Low-Concentration Atropine for Myopia Progression (LAMP) Study: A Randomized, Double-Blinded, Placebo-Controlled Trial of 0.05%, 0.025%, and 0.01% Atropine Eye Drops in Myopia Control

PURPOSE

Low-concentration atropine is an emerging therapy for myopia progression, but its efficacy and optimal concentration remain uncertain. Our study aimed to evaluate the efficacy and safety of low-concentration atropine eye drops at 0.05%, 0.025%, and 0.01% compared with placebo over a 1-year period.

DESIGN

Randomized, placebo-controlled, double-masked trial.

PARTICIPANTS

A total of 438 children aged 4 to 12 years with myopia of at least -1.0 diopter (D) and astigmatism of -2.5 D or less.

METHODS

Participants were randomly assigned in a 1:1:1:1 ratio to receive 0.05%, 0.025%, and 0.01% atropine eye drops, or placebo eye drop, respectively, once nightly to both eyes for 1 year. Cycloplegic refraction, axial length (AL), accommodation amplitude, pupil diameter, and best-corrected visual acuity were measured at baseline, 2 weeks, 4 months, 8 months, and 12 months. Visual Function Questionnaire was administered at the 1-year visit.

MAIN OUTCOME MEASURES

Changes in spherical equivalent (SE) and AL were measured, and their differences among groups were compared using generalized estimating equation.

RESULTS

After 1 year, the mean SE change was -0.27±0.61 D, -0.46±0.45 D, -0.59±0.61 D, and -0.81±0.53 D in the 0.05%, 0.025%, and 0.01% atropine groups, and placebo groups, respectively (P < 0.001), with a respective mean increase in AL of 0.20±0.25 mm, 0.29±0.20 mm, 0.36±0.29 mm, and 0.41±0.22 mm (P < 0.001). The accommodation amplitude was reduced by 1.98±2.82 D, 1.61±2.61 D, 0.26±3.04 D, and 0.32±2.91 D, respectively (P < 0.001). The pupil sizes under photopic and mesopic conditions were increased respectively by 1.03±1.02 mm and 0.58±0.63 mm in the 0.05% atropine group, 0.76±0.90 mm and 0.43±0.61 mm in the 0.025% atropine group, 0.49±0.80 mm and 0.23±0.46 mm in the 0.01% atropine group, and 0.13±1.07 mm and 0.02±0.55 mm in the placebo group (P < 0.001). Visual acuity and vision-related quality of life were not affected in each group.

CONCLUSIONS

The 0.05%, 0.025%, and 0.01% atropine eye drops reduced myopia progression along a concentration-dependent response. All concentrations were well tolerated without an adverse effect on vision-related quality of life. Of the 3 concentrations used, 0.05% atropine was most effective in controlling SE progression and AL elongation over a period of 1 year.

Update in myopia and treatment strategy of atropine use in myopia control

The prevalence of myopia is increasing globally. Complications of myopia are associated with huge economic and social costs. It is believed that high myopia in adulthood can be traced back to school age onset myopia. Therefore, it is crucial and urgent to implement effective measures of myopia control, which may include preventing myopia onset as well as retarding myopia progression in school age children. The mechanism of myopia is still poorly understood. There are some evidences to suggest excessive expansion of Bruch’s membrane, possibly in response to peripheral hyperopic defocus, and it may be one of the mechanisms leading to the uncontrolled axial elongation of the globe. Atropine is currently the most effective therapy for myopia control. Recent clinical trials demonstrated low-dose atropine eye drops such as 0.01% resulted in retardation of myopia progression, with significantly less side effects compared to higher concentration preparation. However, there remain a proportion of patients who are poor responders, in whom the optimal management remains unclear. Proposed strategies include stepwise increase of atropine dosing, and a combination of low-dose atropine with increase outdoor time. This review will focus on the current understanding of epidemiology, pathophysiology in myopia and highlight recent clinical trials using atropine in the school-aged children, as well as the treatment strategy in clinical implementation in hyperopic, pre-myopic and myopic children.

Efficacy and Adverse Effects of Atropine in Childhood Myopia: A Meta-analysis

Importance

Some uncertainty about the clinical value and dosing of atropine for the treatment of myopia in children remains.

Objective

To evaluate the efficacy vs the adverse effects of various doses of atropine in the therapy for myopia in children.

Data Sources

Data were obtained from PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials, from inception to April 30, 2016. The reference lists of published reviews and clinicaltrials.gov were searched for additional relevant studies. Key search terms included myopia, refractive errors, and atropine. Only studies published in English were included.

Study Selection

Randomized clinical trials and cohort studies that enrolled patients younger than 18 years with myopia who received atropine in at least 1 treatment arm and that reported the annual rate of myopia progression and/or any adverse effects of atropine therapy were included in the analysis.

Data Extraction and Synthesis

Two reviewers independently abstracted the data. Heterogeneity was statistically quantified by Q, H, and I2 statistics, and a meta-analysis was performed using the random-effects model. The Cochrane Collaboration 6 aspects of bias and the Newcastle-Ottawa Scale were used to assess the risk for bias.

Main Outcomes and Measures

The primary outcome was a difference in efficacy and the presence of adverse effects at different doses of atropine vs control conditions. The secondary outcomes included the differences in adverse effects between Asian and white patients.

Results

Nineteen unique studies involving 3137 unique children were included in the analysis. The weighted mean differences between the atropine and control groups in myopia progression were 0.50 diopters (D) per year (95% CI, 0.24-0.76 D per year) for low-dose atropine, 0.57 D per year (95% CI, 0.43-0.71 D per year) for moderate-dose atropine, and 0.62 D per year (95% CI, 0.45-0.79 D per year) for high-dose atropine (P < .001), which translated to a high effect size (Cohen d, 0.97, 1.76, and 1.94, respectively). All doses of atropine, therefore, were equally beneficial with respect to myopia progression (P = .15). High-dose atropine were associated with more adverse effects, such as the 43.1% incidence of photophobia compared with 6.3% for low-dose atropine and 17.8% for moderate-dose atropine (χ22 = 7.05; P = .03). In addition, differences in the incidence of adverse effects between Asian and white patients were not identified (χ21 = 0.81; P = .37 for photophobia).

Conclusions and Relevance

This meta-analysis suggests that the efficacy of atropine is dose independent within this range, whereas the adverse effects are dose dependent.

Atropine 0.5% eyedrops for the treatment of children with low myopia: A randomized controlled trial

BACKGROUND

This study aimed to assess the efficacy and safety of atropine 0.5% eyedrops (ATE) for the treatment of children with low myopia (LM).

METHODS

In this study, a total of 126 children with LM were randomly divided into an intervention group (administered 0.5% ATE) and a control group (administered a placebo), with 63 children in each group. The outcome measurements were changes in the spherical equivalent (SE), and axial length (AL), as well as adverse events (AEs).

RESULTS

Compared with placebo, administration of 0.5% ATE led to less progression in LM, as measured by SE, and less increase in AL (P < .01). In addition, no serious AEs occurred in both the groups.

CONCLUSION

About 0.5% ATE was efficacious and safe for controlling myopia in children with LM.

Risk factors for myopia progression in second-grade primary school children in Taipei: a population-based cohort study

PURPOSE

To evaluate the 1-year progression of myopia and associated risk factors in second-grade primary school children.

METHODS

The myopia investigation study in Taipei provided semiannual visual acuity testing and cycloplegic refraction for all second-grade primary school children (mean age: 7.49 years) in Taipei who provided parental consent. A questionnaire was distributed to the participants' parents before the first and third examinations. We evaluated 1-year follow-up data for children noted to have myopia on the first examination. Multinomial logistic regression models were applied to assess risk factors associated with myopia progression. Myopia progression was categorised, based on the change in spherical equivalent (ΔSE) over 1 year, as slow (ΔSE>-0.5 dioptres (D)), moderate (-1.0 D<ΔSE≤-0.5 D) or fast (ΔSE≤-1.0 D). Of the 4214 myopic children, data were analysed for 3256 (77.3%) who completed the 1-year follow-up evaluation.

RESULTS

The baseline SE was -1.43±1.1 D. The average ΔSE was -0.42±0.85 D, with 46.96%, 28.50% and 24.54% of the study subjects showing slow, moderate and fast myopia progression, respectively. When compared with slow myopia progression, fast myopia progression was associated with a greater myopic SE at baseline (OR: 0.67, 95% CI: 0.61 to 0.72) and a shorter eye-object distance when doing near work (OR: 1.45, 95% CI: 1.18 to 1.78). More outdoor activity time and self-reported cycloplegic treatment were not associated with slow myopia progression.

CONCLUSIONS

Children with fast annual myopia progression were more myopic at baseline and had a shorter reading distance. Our study results highlight the importance of having children keep a proper reading distance.

Interventions to Reduce Myopia Progression in Children

Efforts to reduce the progression of myopia in childhood are on the rise, due to an increasing incidence of myopia worldwide and its associated sight-threatening complications. Interventions are aimed at reducing myopia in childhood and include environmental considerations, spectacles, contact lenses, and pharmacological agents. We reviewed recent literature with interventions aimed at reducing myopia progression in children and found that a number of interventions were significant in reducing the progression of myopia. Of these interventions, atropine showed the largest dose-related effect on myopia progression control. Although higher doses are associated with side effects of pupil dilatation, loss of accommodation, near vision blur, and rebound phenomenon, low-dose atropine has also been shown to provide effective myopia control with minimal side effects and rebound. To a lesser degree, bifocal soft contact lenses have also been shown to be effective in reducing the progression of myopia, though compliance is an issue. Similarly, orthokeratology lenses have also been shown to be effective in reducing axial length elongation and myopia progression, though long-term data on its rebound effects are unavailable.