A center-distance soft multifocal contact lens with an over-refraction provides children with myopia the same visual acuity a spectacle lens, according to a research study published in the April issue of Optometry and Vision Science.
The study enrolled 294 children, ages seven to 11, with myopia of -0.75 to -5.00 diopters and 1.00D cylinder or less. The children were fitted bilaterally with +2.50D add Biofinity (CooperVision) multifocal lenses. The initial multifocal power was the spherical equivalent of a standardized subjective refraction, rounded to the nearest 0.25D step.
Researchers found that children achieved best-corrected visual acuity with the +2.50D multifocal—an acuity equal to that achieved with spectacles. Children typically required an over-refraction of -0.50D to -0.75D to achieve this outcome. With a careful over-refraction, these +2.50D add multifocal contact lenses provide good distance acuity, making them viable candidates for myopia control, the investigators concluded.
“Practitioners fitting contact lenses for myopia control frequently ask whether a myopic child sees well with a high-add multifocal," says study author Krystal Schulle, OD, of the University of Houston College of Optometry. "In this study, we show that visual acuity with a +2.50D add center-distance soft multifocal contact lens is not different than with spectacles. We also report the expected spherical over-refraction in order to optimize vision when fitting this particular lens.”
|Schulle K, Berntsen D, Sinnott L, et al. Visual acuity and over-refraction in myopic children fitted with soft multifocal contact lenses. Optom Vis Sci. 2018;95(4):292-8.