Long-term consequences of lenses for myopia control unknown
Studies involving overnight and daily wear contact lenses have shown promise for reducing myopia and suppressing axial length in children, but clinical ramifications have yet to be determined, according to researchers who reviewed clinical trials.
It has been suggested that inducing peripheral myopic defocus may slow the progression of myopia, researchers wrote. The peripheral defocus may be altered using suitable contact lenses or by modifying the shape of the cornea via orthokeratology (OK) contact lenses.
Older theories suggest that conventional single-vision gas-permeable contact lenses slow myopia progression in children, they added.
Researchers evaluated published articles containing clinical studies with contact lenses that attempted to assess their ability to slow myopia progression. Articles with less than 30 subjects enrolled and those that did not include a control treatment were excluded.
Walline and colleagues found no clinically relevant effect of conventional monofocal soft contact lenses on the progression of myopia in children over a 3-year period.
In a retrospective cohort study for OK lenses, the relative reduction in axial length ranged from 6% to 63%, whereas the difference between arms in mean axial length increase ranged from –0.03 mm to 0.42 mm.
Seven studies met the review criteria for multifocal soft contact lens designs, most using active single-vision soft contact lenses as controls and two using single-vision spectacles.
Cycloplegic autorefraction was used in each study.
Reported outcomes varied considerably in multifocal soft designs.
The percentage reduction in the progression of refractive error ranged from 25% to 72% in subjects wearing the investigational device, researchers found. Further, axial length increase ranged from 27% to 80%.
The long-term consequences of these therapies remain unknown, researchers wrote.
“Given the potential published health impact of very large numbers of young children receiving recommendations to wear contact lenses specifically approved to slow myopia progression, it seems appropriate to better categorize the risk of microbial keratitis, the leading cause of vision loss related to contact lens wear in this group,” they wrote. – by Abigail Sutton
Disclosures: The researchers reported no relevant financial disclosures.