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Nightly use of 0.05% atropine eye drops in kids led to a significantly lower incidence of myopia at 2 years, and a lower percentage with fast myopic shift, a randomized trial from Hong Kong showed.

Among children ages 4 to 9 with no myopia but considered to be at-risk, the 2-year cumulative incidence of myopia in the 0.05% atropine group was 28.4%, as compared with 45.9% in a group that received a 0.01% dose of atropine (P=0.005) and 53.0% in a placebo group (P<0.001), reported Jason Yam, MPH, of the Chinese University of Hong Kong and Hong Kong Eye Hospital, and colleagues.

The percentages of participants with fast myopic shift at 2 years were 25.0% compared with 45.1% (P=0.001) and 53.9% (P<0.001), respectively, they detailed in .

"Low-concentration atropine eye drops are effective in reducing myopia progression, have been widely adopted in Asia, and are being further evaluated in randomized trials in many countries," Yam and colleagues wrote, noting, however, that studies of 0.01% atropine "have produced inconsistent findings."

"Of note, whether atropine treatment is effective in delaying myopia onset remains unknown," they added. "A retrospective study suggested that low-concentration atropine should be helpful for delaying myopia onset. However, randomized trials are needed to provide robust evidence on efficacy and safety."

In the current study, known as LAMP2, there was no significant difference between the 0.01% atropine and placebo groups at 2 years in myopia incidence (difference 7.1%, P=0.27) or percentage of participants with fast myopic shift (difference 8.8%, P=0.17).

In an email to 番茄社区, Yam wrote that "before our research, the only established way to delay myopia onset [was] to increase outdoor time, and ... the efficacy is quite modest."

"Early-onset myopia is associated with high myopia later in life, and myopia is irreversible once developed," he continued. "High myopia is associated with eye complications due to eyeball elongation. These blinding complications include myopic macular degeneration, retinal detachment, glaucoma, and cataract."

"Our study therefore provided evidence for atropine being an additional prevention strategy for delaying myopia onset beyond increasing time spent outdoors. While lifestyle modifications to increase time outdoors should be advocated for all children, low-concentration atropine could be a pharmacological intervention considered for children at high risk of developing into myopia," he concluded.

As for secondary outcomes, multiple comparisons showed that 0.05% atropine decreased spherical equivalent myopic shift and axial length elongation significantly more than 0.01% atropine (P<0.001 for both) and placebo (P<0.001 for both) at 2 years. The difference between the 0.01% atropine and placebo groups did not reach statistical significance at this time.

"The LAMP2 study provides the strongest evidence to date that daily administration of 0.05% atropine delays the onset of myopia and meaningfully adds to the evidence that refractive error change and eye growth can be slowed, even before myopia onset," wrote David Berntsen, OD, PhD, of the University of Houston in Texas, and Jeffrey Walline, OD, PhD, of Ohio State University in Columbus, in an . "However, the evidence presented does not yet warrant a change in the standard care of children because we do not yet know the long-term effects of delaying the onset of myopia with low-concentration atropine."

"Ultimately, the implementation of vision screenings that include determining a child's prescription will likely be needed to identify children most likely to become myopic who may benefit from low-concentration atropine," they added. "Additional randomized studies are needed to replicate these findings and to answer questions regarding the long-term outcomes."

In , David Musch, PhD, MPH, and Steven Archer, MD, both of the University of Michigan in Ann Arbor, noted that should atropine treatment for the prevention of myopia or its progression be approved by the FDA, "widespread administration of atropine to prevent myopia in children should not be recommended indiscriminately since children with hyperopia may be harmed if atropine interferes with emmetropization."

"In addition, identifying candidates for atropine treatment would require cycloplegic refraction at multiple ages as most children have hyperopia at birth and may, as their eyes elongate, subsequently develop emmetropia and then myopia," they added. "The need for repeated refractions would add substantially to the cost of atropine use as a general public health measure."

For this double-masked study, which was conducted at the Chinese University of Hong Kong Eye Centre from July 2017 to June 2022, Yam and colleagues randomized 474 children ages 4 to 9 without myopia (cycloplegic spherical equivalent between +1.00 D to 0.00 D and astigmatism less than -1.00 D) in a 1:1:1 ratio to 0.05% atropine, 0.01% atropine, or placebo (n=155). Ultimately, 353 completed the trial.

Myopia was defined as a cycloplegic spherical equivalent of at least -0.50 D in either eye, and fast myopic shift was defined as a spherical equivalent myopic shift of at least 1.00 D.

The most common adverse event -- photophobia -- was reported by 12.9% of participants in the 0.05% atropine group, 18.9% in the 0.01% atropine group, and 12.2% in the placebo group in the second year.

Limitations of the study included potential unmasking of participants due to atropine-induced mydriasis and cycloplegia. Additionally, all participants were Chinese, meaning that generalizability to other populations may be limited.

Furthermore, the duration of the study did not allow for measuring of the final myopic state of participants, who are currently in their third year of follow-up, Yam and colleagues noted. The total intended follow-up duration is 6 years to evaluate longer-term effects.