Elsevier

Ophthalmology

Volume 127, Issue 7, July 2020, Pages 910-919
Ophthalmology

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

https://doi.org/10.1016/j.ophtha.2019.12.011Get rights and content

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.

Section snippets

Methods

The study design has been described previously for the LAMP study phase 1.7 In brief, children 4 to 12 years of age with myopic refraction of at least –1.0 D in both eyes, astigmatism of less than 2.5 D, and documented myopic progression of at least 0.5 D in the previous 1 year were enrolled in this double-blinded, single-center clinical trial. After excluding those with ocular diseases, those who underwent previous interventions (such as atropine, pirenzepine, orthokeratology lens, or other

Results

In total, 383 of the 438 children (87%) 4 to 12 years of age originally randomized to receive atropine 0.05%, atropine 0.025%, atropine 0.01%, or placebo once daily in both eyes in the LAMP phase 1 study were continued in this extended trial (phase 2), with 102, 91, 97, and 93 participants in the 0.05% atropine, 0.025% atropine, 0.01% atropine, and switchover group, respectively (Fig 1). The baseline characteristics of these 383 participants and the 55 participants who dropped out of the study

Discussion

This report presents the second-year results (phase 2) of the LAMP study of 4 treatment groups: 0.05% atropine, 0.025% atropine, and 0.01% atropine used daily for 2 years and switching over from using a placebo during the first year to using 0.05% atropine daily during the second year. The concentration-dependent response remained, and 0.05% atropine continued to be the most effective among 0.05%, 0.025%, and 0.01% atropine groups for myopia control after 2 years.

Since the ATOM 2 study, use of

Acknowledgments

The authors thank all the children and their parents for participating in this clinical trial; Mr. Yuzhou Zhang, Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, for support with statistical analysis; and Ms. Mandy P. H. Ng, Department of Ophthalmology and Visual Sciences, the Chinese University of Hong Kong, for overall coordination and logistic arrangements of the trial.

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Supplemental material available at www.aaojournal.org.

Presented at: the Association for Research in Vision and Ophthalmology, May 1, 2019, Vancouver, Canada Financial Disclosure(s): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Supported in part by the General Research Fund, Research Grants Council, Hong Kong, China (grant no.: 14111515 [J.C.Y.]); the Health and Medical Research Fund, Hong Kong, China (grant no.: 5160836 [L.J.C.]); the Direct Grants of the Chinese University of Hong Kong, Hong Kong, China (grant nos.: 4054193 [L.J.C.], 4054121 [J.C.Y.], and 4054199 [J.C.Y.]); the UBS Optimus Foundation (grant no.: 8984 [J.C.Y.]); the Centaline Myopia Fund (J.C.Y.); and the CUHK Jockey Club Children Eye Care Programme.

HUMAN SUBJECTS: Human subjects were included in this study. The human ethics committees at The Chinese University of Hong Kong approved the study. All research adhered to the tenets of the Declaration of Helsinki. All participants’ parents or guardians provided informed consent, and verbal assent was obtained from the study participants.

No animal subjects were included in this study.

Author Contributions:

Conception and design: Yam, Tang, Tham, Chen, Pang

Analysis and interpretation: Yam, Li, Zhang, Yip, Kam, Ko, Young, Tham, Chen, Pang

Data collection: Yam, Li, Tang

Obtained funding: Yam, Chen

Overall responsibility: Yam, Li, Zhang, Tang, Yip, Kam, Ko, Young, Tham, Chen, Pang

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