Multifocal contact lens in myopia control
Children wearing multifocal contact lenses had a slower progression of their myopia, according to results from a clinical trial funded by the National Eye Institute.
The study finds that children who wore multifocal contact lenses had a slower progression of their myopia, or nearsightedness, over three years. Their findings support using multifocal contacts to treat myopia in children, which could help prevent other vision problems later in life.
A research group led by Dr Jeffrey J. Walline tested whether multifocal contact lenses—with multiple prescriptions in one lens—could slow myopia progression in children. Multifocal contacts include different prescriptions within one lens. They’re usually prescribed to people over 40 years of age to help them see clearly at varying distances.
In this trial, the centre portion of the lenses corrected myopia, focusing light directly on the retina so that distance vision was clear. The outer portion of the lens added focusing power to bring peripheral light rays into focus in front of the retina. Animal studies have shown that focusing light in front of the retina cues the eye to slow growth. In 2019, the FDA approved one multifocal contact lens for myopia control in children. This study tested commercially available soft multifocal contact lenses and also assessed whether adding higher power would prove more effective.
The study included 287 nearsighted children, 7 to 11 years of age. The children required -0.75 to -5.00 diopters of correction to achieve clear distance vision. The researchers randomly assigned the children to wear single vision contact lenses or one of two strengths of multifocal contact lenses: high-add power (+2.50 diopters around the outer edge) or medium-add power (+1.50 diopters). They wore the lenses during the day as often as they comfortably could. The study, which was funded by NIH’s National Eye Institute (NEI), appeared in JAMA on August 11, 2020.
After three years, children in the high-add multifocal contact lens group had the slowest progression of myopia. Their eye prescription changed by -0.60 diopters of correction, compared to -0.89 diopters for the medium-add group and -1.05 diopters for the single vision group. The high-add power contact lenses also effectively slowed the eye growth that causes myopia.
“Compared with single vision contact lenses, multifocal lenses slow myopia progression by about 43% over three years,” says Dr. David A. Berntsen of the University of Houston, one of the study’s principal investigators.