Study: myopic defocus can slow myopia progression
SAN FRANCISCO - According to a study presented here at Academy 2010, dual-focus soft contact lenses were found to significantly reduce myopia progression and eye elongation.
At a press conference sponsored by the American Academy of Optometry, Nicola S. Anstice, BOptom, PhD, reported on a 20-month prospective trial of dual-focus soft contact lenses in 40 children 11 to 14 years old.
Children wore a dual-focus lens in one randomly assigned eye and a single vision distance lens in the fellow eye for 10 months, according to the study abstract. Lenses were then swapped and worn another 10 months.
"We measured myopia progression by change in refractive error and change in eye length over time," Dr. Anstice reported.
"Dual-focus lenses slowed myopia progression by more than 30% in 70% of kids and by more than 50% in 50% of kids," she said. Eye elongation was reduced by 49% in eyes wearing dual-focus lenses in period 1 and 80% in period 2.
"This is accompanied by a corresponding reduction in rate of abnormal eye growth, which is important when thinking of the pathological coordinates with myopia," Dr. Anstice said. "Visual function was maintained with dual-focus lenses, normal acuity, contrast sensitivity and accommodation to near targets."
Dr. Anstice stressed the importance of these study results.
"Twenty-five percent to 40% of kids in Western countries are myopic," she said, "and up to 80% of Chinese children. Myopia has three times the prevalence of diabetes and costs nearly $4 billion per year in the United States.
"High myopia is associated with increased risk of eye disease," she added.