Children's nearsightedness: Atropine eyedrops may delay myopia
- Experts say that developing nearsightedness as a child might be an indication of a higher risk of developing high myopia at a later age.
- Researchers say daily use of low-dose atropine eyedrops in children may delay or prevent the onset of myopia.
- Experts say the findings are intriguing, but more research is needed to determine how effective these eyedrops are in treating and preventing myopia.
Myopia or nearsightedness is when individuals can see close objects clearly but items at a distance are blurred.
Myopia occurs when the eyeball is too long or the cornea is too curved. According to the American Optometric Association, nearly 30% of the population in the United States is nearsighted.
Developing myopia at an earlier age can be an indicator of eventually developing high myopia, which is often defined as when an individual requires -5 dioptres (D) or more of spherical correction. Individuals with high myopia are at greater risk of sight-threatening diseases, such as glaucoma, retinal tears, and cataracts.
“It’s pretty rare when they happen, but when they do, they’re devastating,” Dr. Jeffrey Walline, an associate dean for research at The Ohio State University College of Optometry, told Medical News Today.
Experts believe myopia to be on the rise around the world. It’s estimated that by 2050 about 50% of the world population will have myopia.
A study conducted by researchers at the Chinese University of Hong Kong published in the journal JAMA reports that nightly use of low-dose atropine eyedrops in children may delay or even prevent the onset of myopia.
The prevalence of myopia in children is higher in East Asian countries.
“We’re seeing some increases in the U.S. population as well,” Dr. Evan Silverstein, a pediatric ophthalmologist at Children’s Hospital of Richmond at Virginia Commonwealth University, told Medical News Today. “But the prevalence is not as high as it is in East Asia, which is why a lot of these [myopia] studies are coming out of East Asia.”
Myopia researchers followed children for two years
The researchers used data from the Low-Concentration Atropine for Myopia Prevention (LAMP 2) Trial, a randomized, placebo-controlled, double-masked trial.
The first recruited participant began treatment in the trial in July 2017 and the last participant enrolled in June 2020. The final follow-up session was held in June 2022.
The researchers recruited children between the ages of 4 and 9 with cycloplegic spherical equivalent between +1.00 and 0.00 D, astigmatism of less than -1.00 D. Participants needed to have at least one parent with myopia.
The trial excluded children for several reasons, including if the child had an ocular disease and if the child had already been treated for myopia management.
“They were looking for anyone who had a prescription that was close to being nearsighted but wasn’t yet nearsighted,” Dr. David Berntsen, a professor of optometry at the University of Houston College of Optometry in Texas, told Medical News Today.
High drop-out rate among myopia study participants
Ultimately, 474 children received eyedrops nightly in both eyes over a two-year period.
One group received eye drops consisting of .05% atropine. Another received eye drops consisting of .01% atropine. The third group received placebo drops.
Family members of each participant kept a diary of when the child received eyedrops. Participants who used the drops a mean of 5.25 days a week over the two years were described as having good adherence.
Over the course of the two-year follow up period, 121 participants dropped out for reasons that included no longer wanting to use eyedrops or refusal to attend follow-up exams. Overall, dropout rates were similar among the three groups of participants.
Photophobia, or sensitivity to bright light, was the most common adverse effect reported by families of participants. This was reported by 15 participants in the group that received .05% atropine drops, by 23 participants in the group that received .01% atropine drops, and by 14 participants in the placebo group.
“I don’t think these drops necessarily make you more light sensitive,” said Walline. “If I had to guess [the reason participants dropped out] it’s just the act of having to take drops for something that’s not yet affecting you… sometimes they just get tired of it.”
Delayed onset of myopia
After two years, the cumulative incidence of myopia was 28% in the group of children that received .05% atropine drops, nearly 46% in the group that received .01% atropine drops and 53% for the placebo group.
The group that received .05% atropine drops had significantly lower cumulative myopia incidence than the placebo group and the group receiving .01% atropine drops.
The percentage of participants who experienced aquick increase in the degree of nearsightedness after two years were 25% for the .05% atropine group, 45% for the .01% atropine group and nearly 54% for the placebo group.
Study suggests children tolerate drops well
Walline and Berntsen penned an editorial for JAMA about the LAMP 2 Trial.
“It is not yet known,” they wrote, “whether delaying the onset of myopia will reduce the final degree of myopia as an adult or whether it simply postpones the typical myopia progression to later years.”
The trial does suggest that “kids are able to tolerate [the low-dose atropine drops] very well,” Berntsen pointed out.
He noted that the trial is limited by the fact that it was conducted at a single location: the Chinese University of Hong Kong Eye Centre.
“It’s definitely a promising result, but you can’t generalize things outside of the population that the study was conducted in,” he said.
“We need to think about [whether we can] extrapolate this to caucasians, African- Americans, Hispanic U.S. citizens as well,” added Silverstein.
More research is needed, both doctors agreed.
In particular, Silverstein would like to see research that looks at what happens when children stop using low-dose atropine drops. For example, is there a rebound effect?
“We’re still trying to figure out how long children should be on these eyedrops and how to taper them off rather than stopping abruptly,” he said.
Another considerably longer study would be needed, according to Berntsen, to determine whether the intervention decreases the number of individuals with myopia who later develop vision-threatening conditions such as glaucoma and macular degeneration.
“Those types of studies take quite a while to do,” he noted.
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