Multifocal contact lenses slow the progression of myopia in children – Tips & Results

press release

Tuesday 11 August 2020

NIH-funded clinical study provides independent evidence that multifocal contact lenses reduce myopia worsening.

Children who wore multifocal contact lenses had a slower rate of myopia progression, according to results from a clinical study funded by the National Eye Institute, part of the National Institutes of Health. The findings support an option to control the condition, also called myopia, which increases the risk of cataracts, glaucoma and retinal detachment later in life. Researchers from the Bifocal Lens Study in Myopic Children (BLINK) published the results Aug. 11 in JAMA.

“It is particularly good news to know that children were already achieving optimal visual acuity by the age of 7 and becoming accustomed to wearing multifocal lenses similar to a single vision contact lens. Fitting contact lenses to younger children is not a problem. It’s a safe practice,” said BLINK’s principal investigator, Jeffrey J. Walline, OD, Ph.D., associate dean of research at Ohio State University’s College of Optometry

Myopia occurs when a child’s developing eyes get too long from front to back. Instead of focusing images on the retina—the light-sensitive tissue at the back of the eye—images of distant objects are focused on a point in front of the retina. As a result, people with myopia have good near vision but poor distance vision.

Single vision glasses and contact lenses are used to correct myopia but cannot treat the underlying problem. Multifocal contact lenses — typically used to improve near vision in people over 40 — correct myopia in children while slowing the progression of myopia by slowing eye growth.

The soft multifocal contact lenses are shaped like a porthole and have two basic parts to focus the light. The middle part of the lens corrects myopia so that distance vision is clear and focuses the light directly on the retina. The outer part of the lens adds focusing power to focus the peripheral light rays in front of the retina. Animal studies show that focusing light in front of the retina causes the eye to grow slowly. The higher the power added, the further in front of the retina it focuses the peripheral light.

In comparison, single vision glasses and standard contact lenses focus peripheral light to a point behind the retina, which causes the eye to continue growing.

Researchers investigated whether high power lenses were better at slowing the progression of myopia and eye growth than medium power lenses. They found that only the high add-on power contact lenses caused a significant slowdown in eye growth.

In addition to multifocal lenses, other myopia control options include orthokeratology contact lenses worn overnight to reshape the cornea or low-dose atropine eye drops used at bedtime.

The US Food and Drug Administration approved a lens for controlling myopia in November 2019, but multifocal contact lenses have been used off-label to slow the progression of myopia for many years.

Myopia has increased in prevalence over the past five decades. In 1971, 25% of Americans were myopic, compared to 33% in 2004. By 2050, the global prevalence of myopia is estimated at 54%, and the prevalence of high myopia, the most severe form, is projected to rise to 10%. Severe myopia means that a person’s vision requires at least -5.00 diopters, the unit of focusing power correction needed to optimize distance vision.

The reasons for the increase are unclear, but there is evidence that nearby work, such as B. screen time, and the shrinking time outdoors during early eye development contribute to this. Genetic factors also play a role in the predisposition to myopia.

There are no tests to determine which individuals with myopia will progress to high myopia, but the younger a child is affected, the greater the chance their myopia will progress if there is no intervention to slow it down.

Study participants were 287 myopic children aged 7 to 11 years. At baseline, children required a correction of -0.75 to -5.00 diopters to achieve clear distance vision. The children were randomly assigned to wear single vision or multifocal lenses with the outer lens having either a high add power (+2.50 diopters) or a medium add power (+1.50 diopters). They wore the lenses as often as they could comfortably during the day. All participants were evaluated at Ohio State University, Columbus, or University of Houston clinics.

At three years, children in the high-added multifocal group had the slowest progression in myopia. Mean myopia progression, measured by changes in vision required to correct distance vision, was -0.60 diopters for the high acuity group, -0.89 diopters for the moderately impaired group, and -1.05 diopters for the group with single-sightedness.

The multifocal lenses also slowed eye growth. Adjusted eye growth at three years was 0.42 mm for the high vision group, 0.58 mm for the intermediate vision group, and 0.66 mm for the single vision group.

“Greater myopia and longer eyes are associated with an increased prevalence of eye disorders that can lead to visual impairment. Our study shows that ophthalmologists should equip children with high add-on multifocal contact lenses to maximize myopia control and slow eye growth,” said lead investigator David A. Berntsen, OD, Ph.D., associate professor and Golden-Golden -Professor of Optometry at the University of Houston. “Compared to single vision contact lenses, multifocal lenses slow the progression of myopia by approximately 43% over three years.”

“There is a clear benefit of multifocal lenses after three years, but further studies are needed to determine the ideal length of lens wear. Researchers need to determine how durable the prevention of myopia progression will be once children stop wearing multifocal lenses,” said Lisa A. Jones-Jordan, Ph.D., senior researcher with the Data Coordinating Center at Ohio State University. A follow-up study is underway to see if the benefits in children in this study persist if they stop treatment.

“We also need more information about the exact nature of the visual signals that slow eye growth. If we better understood this process, perhaps we could maximize it to produce an even stronger treatment effect,” said principal investigator Donald O. Mutti, OD, Ph.D., EF Wildermuth Foundation Professor of Optometry at Ohio State.

Multifocal lenses tested in the study are available from CooperVision. At the time of the study, the lenses were being used off-label for myopia control.

The study was funded by National Eye Institute (NEI) grants U10 EY023204, EY023206, EY023208, EY023210, P30EY007551, UL1TR001070. ClinicalTrials.gov Identifier: NCT02255474.

To learn more about myopia, visit https://www.nei.nih.gov/learn-about-eye-health/resources-for-health-educators/outreach-materials/myopia-nearsightedness

NEI leads the federal government’s research on the visual system and eye diseases. NEI supports fundamental and clinical scientific programs to develop treatments for vision preservation and to address the unique needs of people with vision loss. Visit https://www.nei.nih.gov for more information.

About the National Institutes of Health (NIH):NIH, the country’s medical research agency, comprises 27 institutes and centers and is part of the US Department of Health and Human Services. The NIH is the primary federal agency that conducts and supports basic, clinical, and translational medical research investigating the causes, treatments, and cures for common and rare diseases. For more information about the NIH and its programs, visit www.nih.gov.

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References:

Walline, JJ; Wanderer, MK; Mutti, DO; Jones-Jordan, LA; Sinnott, LT; Gaume Giannoni, A; Bickel, KM; Schulle, KL; Nixon, A.; Pierce, GE; Berntsen, DA “Effect of high add power, medium add power, or single power contact lenses on myopia progression in children: the BLINK randomized clinical trial,” published August 11, 2020 in JAMA. DOI: 10.1001/jama.2020.10834

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