Dilating eyedrops may delay ― and perhaps even prevent ― the onset of myopia in children, according to findings from a study published today in JAMA. The study was conducted by researchers in Hong Kong.
Myopia is irreversible once it takes root and can contribute to other vision problems, such as macular degeneration, retinal detachment, glaucoma, and cataracts. The incidence of nearsightedness has nearly doubled since the 1970s, rising from 25% of the US population to nearly 42%. Children have been particularly affected by the increase; reasons may include spending more time indoors looking at screens, experts say.
"Myopia is an ongoing and growing worldwide concern. This is of particular importance because of the change in children's lifestyle, such as decreased outdoor time and increased screen time during and after the COVID-19 pandemic," Jason C. Yam, MPH, of the Department of Ophthalmology and Visual Services at the Chinese University of Hong Kong, told Medscape Medical News.
Yam said that while encouraging children to engage more in outdoor activity and spend less time using screens would help delay myopia, pharmaceutical interventions are needed, given myopia's potential lifelong effects.
Putting Eyedrops to the Test
In 2020, Yam and colleagues reported results of the Low-Concentration Atropine for Myopia Progression (LAMP) study, which showed that eyedrops containing a solution of 0.05% atropine worked best at slowing the progression of myopia in 4- to 12-year-olds who already had the condition. Atropine relaxes eye muscles, causing dilation.
In that study, Yam and colleagues measured the rate of change in the eye's ability to see at a great distance using a unit of measure known as the diopter. The higher the diopter, the more myopic a person's vision. The 0.05% atropine solution was better at slowing this decline than placebo or solutions that contained a lower concentration of the substance.
The new study enrolled 474 children who were evenly divided by sex. None of the children had myopia when the trial began. Of that starting group, 353 children (age, 4 – 9 years) completed the study, which involved receiving eyedrops once nightly in both eyes for 2 years.
Some children (n = 116) received 0.05% atropine, others (n = 122) received 0.01% atropine, and the rest (n = 115) received placebo drops. Yam and colleagues assessed how many children in each group had myopia after 2 years, as measured by a decline of at least a half diopter in one eye.
At the 2-year mark, more than half of children who received the placebo drops (61/115) had developed myopia, as had nearly half of those given 0.01% atropine (56/122). But fewer than one third of children (33/116, 28.4%) who had received the drops with 0.05% atropine developed myopia during that period, the researchers reported.
The percentage of children with myopia in the placebo group (39/128, 30.5%) was larger by the end of the first year of the study than was the share of children in the 0.05% atropine group by the end of the trial. (Between 12 months and 24 months, 13 children in the placebo group left the study.) The main adverse event, in all treatment groups, was discomfort when exposed to bright light, according to the researchers.
"We are continuing the current study with the total intended follow-up duration of at least 6years," added Yam, who hopes to determine whether the 0.05% atropine solution not only delays myopia but also prevents it altogether. While myopia is a concern worldwide, the condition is particularly prevalent in East Asia.
Mark A. Bullimore, MCOptom, PhD, FAAO, an adjunct professor at the University of Houston's College of Optometry and a consultant to ophthalmologic companies, called the trial "a landmark study. Finding children who are eligible and parents who are willing to deal with 2 years of drops is no small feat.
"The 0.05% atropine, on average, delays onset of myopia by a year," Bullimore noted. He pointed to the similar percentages of myopia with placebo at 12 months compared with 0.05% atropine 1 year later. He added that few clinicians in the United States use higher than 0.05% atropine for control of myopia because doing so can lead to excessive dilation and difficulty focusing.
While preventing myopia altogether would be ideal, simply delaying its onset can also be of tangible benefit, Bullimore said. In an article published last month, Bullimore and Noel A. Brennan of Johnson & Johnson Vision showed that delaying the onset of myopia reduces its severity.
"Optometrists prescribe low-concentration atropine already for myopia control, and there's no reason now ― in the light of this study ― that they wouldn't also do it to delay onset," Bullimore said.
But in an editorial accompanying the journal article, David A. Berntsen, OD, PhD, and Jeffrey J. Walline, OD, PhD, both of the University of Houston, write that a change in practice would be premature.
"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," they write.
Identifying which children to consider for treatment is "a challenge," they note, because those who are not nearsighted typically do not undergo routine examination unless they have failed a vision test.
"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," Berntsen and Walline write.
Yam and co-investigators have applied for a patent on a 0.05% atropine solution. Bullimore reports relationships with Alcon Research, Inc,CooperVision, Inc, CorneaGen, Inc, EssilorLuxottica SA, Eyenovia, Inc, Genentech, Inc, Johnson & Johnson Vision, Inc, Lentechs, LLC, Novartis AG and Vyluma, Inc, and is the sole owner of Ridgevue Publishing, LLC and Ridgevue Vision LLC.
JAMA. Published online February 14, 2023. Abstract, Editorial
Marcus A. Banks, MA, is a journalist based in New York City who covers health news with a focus on new cancer research. His work appears in Medscape, Cancer Today, The Scientist, Gastroenterology and Endoscopy News, Slate, TCTMD, and Spectrum.
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Cite this: Eyedrops Delay, May Even Prevent, Nearsightedness - Medscape - Feb 14, 2023.