The effect of concentric and aspheric multifocal soft contact lenses on binocular vision in young adult myopes.

PURPOSE: Multifocal soft contact lenses (MFCLs) are prescribed to inhibit myopia progression; these include aspheric and concentric designs. The effects of MFCLs on visual quality, accommodation and vergence in young-adult myopes were evaluated.

METHODS

Participants were twenty-six myopes (19-25 years, spherical equivalent -0.50 to -5.75D), with normal binocular vision and no past myopia control. Pupil sizes were 4.4 ± 0.9 mm during distance viewing and 3.7 ± 0.8 mm at near. In random order, participants wore four MFCLs: Proclear single vision distance, MiSight concentric dual focus (+2.00D), distance center aspheric (Biofinity, +2.50D) (CooperVision lenses), and NaturalVue aspheric (Visioneering Technologies). Testing included visual acuity, contrast sensitivity (Pelli-Robson), stereoacuity, accommodation response, negative and positive relative accommodation, horizontal phorias, horizontal fusional vergence and AC/A ratio, and a visual quality questionnaire.

RESULTS

The four lenses differed in distance (p = 0.001) and near visual acuity (p = 0.011), and contrast sensitivity (p = 0.001). Compared with the single vision lens, the Biofinity aspheric had the greatest visual impact: 0.19 ± 0.14 logMAR distance acuity reduction, 0.22 ± 0.15 log contrast sensitivity reduction. Near acuity was affected less than distance acuity; the reduction was greatest with the NaturalVue (0.05 ± 0.07 logMAR reduction). The MFCLs altered the autorefraction measure at distance and near (p = 0.001); the accommodation response was less with aspheric lenses. Negative relative accommodation reduced with the aspheric lenses (p = 0.001): by 0.9 ± 0.5D with Biofinity and 0.5 ± 0.7D with NaturalVue. Exophoric shifts were greater with aspheric lenses (1.8 ± 2.4Δ Biofinity, 1.7 ± 1.7Δ NaturalVue) than with the concentric MiSight (0.5 ± 1.3Δ).

CONCLUSIONS

MFCLs alter visual performance, refraction and vergence; two aspheric lenses had greater effect than a concentric lens.