The following is a summary of “Effect of multifocal spectacle lenses on accommodative errors over time: Possible implications for myopia control,” published in the March 2023 issue of Ophthalmology by Varnas, et al.

For a study, researchers sought to investigate the impact of multifocal spectacle lenses on accommodative errors and whether this effect changed over time. 

A total of 52 individuals aged between 18 to 27 years and with myopia were randomly assigned to one of two progressive addition lens (PAL) types with 1.50 D additions and varying horizontal power gradients across the near-periphery boundary. The lags of accommodation were measured at various near distances using a Grand Seiko WAM-5500 autorefractor and a COAS-HD aberrometer with both the distance correction and the near PAL correction. The neural sharpness (NS) metric was used for the COAS-HD. The measurements were repeated at three-month intervals for a total of 12 months. At the final visit, lags were measured for booster addition powers of 0.25, 0.50, and 0.75 D. 

At baseline, both PALs reduced accommodative lag when compared to single vision lenses (SVLs) for all near distances measured with the Grand Seiko autorefractor (P < 0.05 and P < 0.01 for PAL 1 and PAL 2, respectively). For the COAS-HD, PAL 1 reduced accommodative lag at all near distances (P < 0.02), while PAL 2 only reduced lag at 40 cm (P < 0.02). Lags measured with the COAS-HD were greater for shorter target distances with PALs. After 12 months of wear, the PALs no longer significantly reduced accommodative lags, except at 40 cm distance, but booster adds of 0.50 D and 0.75 D decreased lags to the levels measured at baseline or lower. 

To effectively reduce accommodative lag with PALs, addition power should be tailored to the typical working distances, and after the first year of wear, should be boosted by at least 0.50 D to maintain efficacy.

Reference: jov.arvojournals.org/article.aspx?articleid=2785411