Low doses of the eyedrops ophthalmologists use to dilate your pupils during an eye exam are not able to slow the progression of nearsightedness (myopia) in children, a new clinical trial has found.
Atropine eyedrops at a concentration of 0.01% did not outperform placebo drops in slowing either myopia progression or elongation of the eye among children after two years of treatment, the study results show.
The results contradict findings from other recent trials that showed a benefit from using low-dose atropine drops to arrest myopia, the researchers said.
Stronger concentrations of atropine -- 0.5% to 1% -- have long been used by pediatric eye doctors to slow the progression of nearsightedness, the study authors said in background notes.
However, such doses cause light sensitivity and blurry near vision when kids receive the drops nightly, the researchers said. Lower concentrations have fewer side effects, and so it was hoped that low-dose atropine would be effective.
By 2030, it's predicted that 39 million people in the United States will have myopia. By 2050, that number is expected to grow to 44 million in the United States and to 50% of the global population.
The study enrolled 187 U.S. children between 5 to 12 years of age with low or moderate myopia. Low-dose atropine was randomly prescribed to 125 of the children, while 62 received placebo drops.
After the two-year treatment period, the investigators found no significant differences between the two groups in terms of myopia or eye structure compared to where the kids started. This was also true six months after treatment stopped.
The study's lead co-author, Dr. Michael Repka, noted that previous clinical trials showing benefit from low-dose atropine mostly were conducted in East Asia.
"The absence of a treatment benefit in our U.S.-based study, compared with East Asian studies, may reflect racial differences in atropine response,"according to Repka, a professor of ophthalmology at Johns Hopkins University in Baltimore.
"The study enrolled fewer Asian children, whose myopia progresses more quickly, and included Black children, whose myopia progresses less quickly compared with other races,"he explained in a news release from the U.S. National Eye Institute.
Among children, myopia stabilizes in about half around the time they reach age 16, and among an increasingly larger percentage as they get older.
By the early 20s, about 10% of individuals with myopia will continue to grow more nearsighted, and by 24 years, that percentage is 4%, the researchers said.
"It's possible that a different concentration of atropine is needed for U.S. children to experience a benefit,"said study co-author Dr. Katherine Weise, a professor at the University of Alabama Birmingham. "Clinical researchers could evaluate new pharmaceuticals and special wavelengths of light in combination with optical strategies, like special glasses or contact lenses, to see what works in reducing the progression of myopia."
Weise added that vision scientists may help figure out what's different about the myopic eye, even among different races and ethnicities, to help develop new treatment strategies.
"It will take a real convergence of eye research to solve the environmental, genetic, and structural mystery of myopia,"Weise said.
The clinical trial results were published online July 13 in JAMA Ophthalmology.
More information
The U.S. National Eye Institute has more about myopia.
SOURCE: U.S. National Eye Institute, news release, July 13, 2023
