Tag: myopia

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Study Shows Effectiveness of Method to Stem Myopia

On By ModernMedia
Photo by Ksenia Chernaya

Capping ten years of work to stem the tide of myopia, David Berntsen, Professor of Optometry at the University of Houston, is reporting that his team’s method to slow myopia not only works – but lasts.

The original Bifocal Lenses In Nearsighted Kids (BLINK) Study showed that having children with myopia wear high-add power multifocal contact lenses slows its progression. Now, new results from the BLINK2 Study, that continued following these children, found that the benefits continue even after the lenses are no longer used.

“We found that one year after discontinuing treatment with high-add power soft multifocal contact lenses in older teenagers, myopia progression returns to normal with no loss of treatment benefit,” reports Berntsen in JAMA Ophthalmology.

The study was funded by the National Institutes of Health’s National Eye Institute with collaborators from the Ohio State University College of Optometry.

In Focus: A Major Issue

Leading the team at the University of Houston, Berntsen takes on a significant challenge. By 2050 almost 50% of the world (5 billion people) will be myopic. Myopia is associated with an increased risk of long-term eye health problems that affect vision and can even lead to blindness.

From the initial study, high-add multifocal contact lenses were found to be effective at slowing the rate of eye growth, decreasing how myopic children became. Because higher amounts of myopia are associated with vision-threatening eye diseases later in life, like retinal detachment and glaucoma, controlling its progression during childhood potentially offers an additional future benefit.

“There has been concern that the eye might grow faster than normal when myopia control contact lenses are discontinued. Our findings show that when older teenagers stop wearing these myopia control lenses, the eye returns to the age-expected rate of growth,” said Berntsen.

“These follow-on results from the BLINK2 Study show that the treatment benefit with myopia control contact lenses have a durable benefit when they are discontinued at an older age,” said BLINK2 study chair, Jeffrey J. Walline, associate dean for research at the Ohio State University College of Optometry.

Eye Science

Myopia occurs when a child’s developing eyes grow too long from front to back. Instead of focusing images directly on the retina, they are focused at a point in front of the retina.

Single vision prescription glasses and contact lenses can correct myopic vision, but they fail to treat the underlying problem, which is the eye continuing to grow longer than normal. By contrast, soft multifocal contact lenses correct myopic vision in children while simultaneously slowing myopia progression by slowing eye growth.

Designed like a bullseye, multifocal contact lenses focus light in two basic ways. The centre portion of the lens corrects nearsightedness so that distance vision is clear, and it focuses light directly on the retina. The outer portion of the lens adds focusing power to bring the peripheral light into focus in front of the retina. Animal studies show that bringing light to focus in front of the retina may slow growth. The higher the reading power, the further in front of the retina it focuses peripheral light.

BLINK Once…Then Twice

In the original BLINK study, 294 myopic children, ages 7 to 11 years, were randomly assigned to wear single vision contact lenses or multifocal lenses with either high-add power (+2.50 diopters) or medium-add power (+1.50 diopters). They wore the lenses during the day as often as they could comfortably do so for three years. All participants were seen at clinics at the Ohio State University, Columbus, or at the University of Houston.

After three years in the original BLINK study, children in the high-add multifocal contact lens group had shorter eyes compared to the medium-add power and single-vision groups, and they also had the slowest rate of myopia progression and eye growth.

Of the original BLINK participants, 248 continued in BLINK2, during which all participants wore high-add (+2.50 diopters) lenses for two years, followed by single-vision contact lenses for the third year of the study to see if the benefit remained after discontinuing treatment.

At the end of BLINK2, axial eye growth returned to age-expected rates. While there was a small increase in eye growth of 0.03 mm/year across all age groups after discontinuing multifocal lenses, it is important to note that the overall rate of eye growth was no different than the age-expected rate. There was no evidence of faster than normal eye growth.

Participants who had been in the original BLINK high-add multifocal treatment group continued to have shorter eyes and less myopia at the end of BLINK2. Children who were switched to high-add multifocal contact lenses for the first time during BLINK2 did not catch up to those who had worn high-add lenses since the start of the BLINK Study when they were 7 to 11 years of age.

By contrast, studies of other myopia treatments, such as atropine drops and orthokeratology lenses that are designed to temporarily reshape the eye’s outermost corneal layer, showed a rebound effect (faster than age-normal eye growth) after treatment was discontinued.

“Our findings suggest that it’s a reasonable strategy to fit children with multifocal contact lenses for myopia control at a younger age and continue treatment until the late teenage years when myopia progression has slowed,” said Berntsen.

Source: University of Houston

Categories : Ophthalmology PaediatricsTags :

No Cure for Myopia Progression in Sight as Eyedrops Trial Flops

On By ModernMedia
Photo by CDC on Unsplash

A US study shows that use of low-dose atropine eyedrops, commonly used in a higher dose to treat lazy eye, was no better than a placebo at slowing myopia progression and elongation of the eye among children treated for two years.

The first randomised controlled trial of its kind aimed at identifying an effective way to manage myopia was published last week in JAMA Ophthalmology. It was conducted by the Pediatric Eye Disease Investigator Group at at Vanderbilt University Medical Center (VUMC) and 11 other hospitals and practices across the United States and funded by the National Eye Institute (NEI).

“We found, interestingly, and honestly shockingly, that there was no difference in the use of 0.01% atropine and placebo in treating these children who ranged in age from 5 to 12,” said associate professor Lori Ann Kehler, OD, and the Vanderbilt site principal investigator for the study.

The onset of myopia usually occurs between the ages of 7 and 16 when developing eyes can start growing too long axially (from front to back). Instead of focusing images on the retina, images of distant objects are focused at a point in front of the retina which causes people to have poor distance vision while their near vision remains unchanged.

The condition results in the need for eyeglasses to improve distance vision, and it can also result in medical complications and serious uncorrectable vision loss later in life, like retinal detachments or myopic macular degeneration.

The study contradicts earlier studies from East Asia that showed the small dose of atropine is effective in slowing progression of myopia.

In 2017 the Academy of Ophthalmology endorsed the findings from East Asia saying that although the FDA had not approved atropine for this use, there was sufficient evidence for prescribing the low dose for myopia. Ophthalmologists across the country, including at VUMC, began to offer the prescription to young patients with myopia.

“That was a really exciting finding at the time because we had had no treatment options for many years,” Kehler said. The prescription of atropine for treating myopia is not covered by most insurance plans.

“The incidence of myopia is increasing worldwide,” Kehler said. “By 2030 it’s predicted that 39 million people in the US will have myopia. By 2050 that number is expected to increase to more than 44 million people in the US and to 50% of the global population. Once it’s detected in children, it tends to get worse every year,” she said. “Investigators all over the world have tried strategies to intervene, to either stop or slow the worsening of myopia.”

Kehler said it is not known why the incidence of myopia is increasing. “There are several theories. Some believe it’s the increase in the use of screens and screen time, but myopia was increasing even before screens were part of children’s lives. Others think it has to do with industrialisation. We were an agricultural society. We were outside more. We weren’t reading. We weren’t looking up close all day. Really, the prevailing thought is whether we’re at a screen or looking at a math book or reading most of the day, we think the lack of sunlight and sustained near effort is what’s causing the increase of myopia.”

Kehler said the percentage of children with myopia using the atropine drop at VUMC is low and estimates fewer than 5% of children with myopia are using the drops nationally.

Going forward, eye specialists should have a frank discussion with parents of children with myopia about the conflicting data between the Asian studies and the new U.S. study.

“The absence of a treatment benefit in our US-based study, compared to East Asian studies, may reflect racial differences in atropine response. The study enrolled fewer Asian children, whose myopia progresses more quickly, and included Black children, whose myopia progresses less quickly compared with other races,” noted the study’s lead co-author, Michael X. Repka, MD, professor of Ophthalmology at Johns Hopkins University, in a news release from the NEI.

“All the studies have shown the drops are safe, so we aren’t putting children at risk if we continue to prescribe the 0.01%,” Kehler said. “But we are telling them there is a difference in these studies and it might have to do with your genetics; it might be that it’s more effective in children from Asia than in the U.S. population,” she said.

Further study is needed, Kehler said. The next step is likely to study a higher dose of atropine to see if children in the U.S. experience a benefit.

The LAMP study out of Hong Kong found that 0.05% might be more effective.

Kehler said other groups are studying the use of red-light therapy to slow the progression of myopia, and there are also new eyeglass lenses that have been developed to slow the progression of myopia, but they are not yet available in the U.S.

“It’s much harder to get drops in very young children,” Kehler said. “But if we had a spectacle option, that would open the door to treating our younger patients.”

Myopia usually stabilises in about half of children around 16 years of age and among an increasingly larger percentage as they get older. By their early 20s, about 10% of individuals with myopia will continue to grow more nearsighted, and by age 24 that percentage is 4%.

Source: Vanderbilt University Medical Center

Categories : Ophthalmology PaediatricsTags :

Atropine Eyedrops Fail to Slow Myopia Progression in US Children

On By ModernMedia
Photo by Jeffrey Riley on Unsplash

Use of low-dose atropine eyedrops (concentration 0.01%) was no better than placebo at slowing myopia progression and elongation of the eye among children treated for two years, according to a randomised controlled trial conducted in the US. The trial aimed to identify an effective way to manage this leading and increasingly common cause of refractive error, which can cause serious uncorrectable vision loss later in life. Results from the trial, published in JAMA Ophthalmology, contradict those from recent trials in East Asia.

The study was conducted by the Pediatric Eye Disease Investigator Group (PEDIG) and funded by the National Eye Institute (NEI).

“The overall mixed results on low-dose atropine show us we need more research. Would a different dose be more effective in a US population? Would combining atropine with other strategies have a synergistic effect? Could we develop other approaches to treatment or prevention based on a better understanding of what causes myopia progression?” said Michael F. Chiang, MD, director of the NEI, which is part of the National Institutes of Health.

Identifying an optimal approach for preventing high (advanced) myopia is urgently needed given the escalating prevalence of myopia overall and the risk of it progressing to high myopia. By 2030, it’s predicted that 39 million people in the U.S. will have myopia. By 2050, that number is expected to grow to 44 million in the U.S. and to 50% of the global population.

Much stronger concentrations of atropine eyedrops (0.5-1.0%) have long been used by pediatric eye doctors to slow myopia progression. While effective, such doses cause light sensitivity and blurry near vision while on the nightly eyedrops. Thus, there is interest in clinical studies assessing lower concentrations that have been shown to have fewer side effects.

“The absence of a treatment benefit in our US-based study, compared with East Asian studies, may reflect racial differences in atropine response. The study enrolled fewer Asian children, whose myopia progresses more quickly, and included Black children, whose myopia progresses less quickly compared with other races,” noted the study’s lead co-author, Michael X. Repka, M.D., professor of ophthalmology, Johns Hopkins University.

For the study, 187 children ages 5 to 12 years with low-to-moderate bilateral myopia were randomly assigned to use nightly atropine (0.01%) (125 children) or placebo (62 children) eyedrops for two years. Study participants, their parents, and the eye care providers were masked to the group assignments.

After the treatment period, and 6 months after treatment stopped, there were no significant differences between the groups in terms of changes in degree of myopia compared with baseline. Nor were there significant differences in axial length within the two groups when compared with baseline measurements.

“It’s possible that a different concentration of atropine is needed for US children to experience a benefit,” noted the study’s other lead co-author, Katherine K. Weise, OD, professor, University of Alabama at 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.”

Among children, myopia will stabilise in about half of children around age 16 years, and among an increasingly larger percentage as they get older. By their early twenties, about 10% of individuals with myopia will continue to grow more nearsighted, and by age 24 years that percentage is 4%.

“Vision scientists may help us figure out what’s different about the myopic eye, even among different races and ethnicities, to help create new treatment strategies,” she said. It will take a real convergence of eye research to solve the environmental, genetic, and structural mystery of myopia.”

Source: NIH/National Eye Institute