Accommodative responses of young adult myopes wearing multifocal contact lenses

Abstract

Purpose : Previous research has shown variable influence of multifocal soft contact lenses (MFCL) on accommodation in non-presbyopes. We investigated accommodative responses in young adult myopes wearing MFCL designs, which are typically prescribed to inhibit myopia progression, in comparison to an absolute presbyope.

Methods : Twenty adults aged 18-25 yrs (14 females, 6 males) with myopia (SER: −0.50 to −5.50D, mean −2.1±1.6D) normal binocular vision function and no previous myopia control intervention wore 5 lens designs in random order: Proclear single vision distance (SV), MiSight concentric dual-focus (+2.00D), distance centered aspheric +1.50 Add (MF1) and +2.50 Add (MF2) (CooperVision) and NaturalVue aspheric (NV: Visioneering Technologies, +8 to +11D at pupil edge). With binocular correction and viewing, accommodative error was measured at 0,1,2,3 and 4D vergence demands using a Grand Seiko WAM-5500 Autorefractor. Measurements were evaluated by comparison to an absolute presbyopic eye.

Results : Compared to SV, aspheric designs MF1, MF2 and NV reduced accommodative response in young adult myopes by 0.5±0.4D at 1m (p<0.001), 0.5±0.5D at 50cm (p<0.02 MF1,MF2), 0.6±0.6D at 33cm (p<0.001) and 1.0±0.7D at 25cm (p<0.001), with no significant differences between these three designs except at 50cm, where NV was not different from SV and MiSight. MiSight showed no significant difference from SV at any distance (p>0.54). Aspheric designs MF1, MF2 and NV reduced accommodative gain per D of demand by 0.28±0.20D from SV and 0.25±0.25D from MiSight. The absolute presbyope showed a reduction in accommodation error of 0.19±0.07D/D in MF1, MF2 and NV lens designs, which were not significantly different from each other but were less than in young adults (p=0.001). MiSight did not show a significant difference in accommodative response when comparing young adults to the absolute presbyope (p=0.29). Mean pupil size in young adults was 4.2±0.8mm at distance and 3.6±0.5mm at 33cm, and there was no interaction between pupil size or level of myopia and accommodative response.

Conclusions : A significant reduction in accommodative response was evident in young myopic eyes wearing aspheric MFCL designs, although the reductions not due to the lens design (ie. greater than that occurring for the presbyope) were on average less than 0.1D. The concentric dual-focus design did not appear to influence accommodative response in young adult myopes.

This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.