A new Cochrane review has analysed the effectiveness of spectacles, contact lenses, pharmaceutical agents and combination treatments in managing myopia.
The authors highlighted that whilst antimuscarinic drugs, such as atropine, are effective in slowing myopia progression, they can lead to adverse ocular side effects.
They also found that multifocal contact lenses and spectacles “may also confer a small benefit” in limiting myopia progression.
The study highlighted that although orthokeratology lenses are not intended to modify refractive error, the lenses are more effective than single vision lenses in slowing axial elongation.
The Cochrane Interventions to slow progression of myopia in children review found “only low or very low-certainty evidence” to support the use of rigid gas permeable lenses and spherical aberration soft contact lenses in managing myopia.
The study method
In assessing the existing evidence on myopia management, researchers analysed the results of 41 randomised controlled trials.
They excluded studies where participants were older than 18 years at baseline or had less than 0.25 diopters spherical equivalent myopia.
The researchers highlighted that two studies found undercorrection of myopia increased progression when compared to children wearing fully corrected single vision lenses.
Across the studies examined, children wearing multifocal spectacle lenses progressed on average 0.14D less than children wearing single vision lenses.
Those who wore bifocal soft contact lenses or ortho-k lenses had less axial elongation than children wearing single vision soft contact lenses.
“If future investigators find a clinically and statistically significant treatment effect, they should determine whether the effect continues to be sustained after treatment”
Children receiving atropine eye drops, pirenzepine gel or cyclopentolate eye drops showed “significantly less” myopic progression compared to children receiving placebo.
Myopia progression was slowed by 1.00D, 0.31D and 0.34D respectively.
However, the authors noted that the pharmaceutical interventions can result in blurred near vision, sensitivity to light, some discomfort and itching and medication residue on the eyelids and eyelashes.
“Spectacles and contact lenses, if used properly, are safe and effective,” the report noted.
A way forward
Turning to implications for practice and research, the authors highlighted that further investigations of myopia control must be conducted to find a treatment that is clinically meaningful and beneficial with fewer adverse side effects.
“If future investigators find a clinically and statistically significant treatment effect, they should determine whether the effect continues to be sustained after treatment is discontinued and should attempt to determine the true mechanism of the treatment effect,” the report stated.
Last year, the US Food and Drug Administration approved CooperVision’s MiSight contact lens for slowing the progression of myopia in children aged between eight and 12 at the beginning of treatment.
Although atropine is not currently licensed in UK, the Childhood Atropine for Myopia Progression study is examining the effect of low-dose 0.01% atropine in a study involving 289 children across five UK centres.
The children will instil one drop in each eye daily for two years, with 193 children receiving atropine and the remaining study participants receiving a placebo.
Image credit: Pixabay/Luisella Planeta Leoni