Abstract
Purpose :
To compare HOAs (total, spherical and coma ) induced by 3 different soft multifocal lenses (SMFL) at different distances and to determine for each distance the relationship between the pupil diameter and HOAs vs lenses used.
Methods :
Myopic young adults were randomly fitted with 3 types of SMFL (L1- Etafilcon A ; L2- Omafilcon A ; L3- Comfilcon A) . A 30 minutes break is observed between each test. Total HOAs, spherical aberrations (SA) and coma (C) are evaluated (OPD Scan, Nidek) without lenses, and while wearing each lens. Measurements are taken in distance vision, at 50 ,33 and 20 cm . The measurement of the pupil in dynamics was carried out with an open field refractor (Grand Seiko, Wam 5500) in photopic condition.
Statistical anlaysis was done by performing a two-factor within-subjects (3x4) repeated measures Anova. A post-hoc test is performed when significant differences are found. A Pearson correlation is established between aberrations, pupillary diameter, at each distance.
Results :
The clinical population consisted of 9 M/18 F, aged 25.1 ± 1.6 years; being -2.75 ± 0.5 D. There is a significant increase in total HOAs with SMFL vs. naked eye . Every lens shows a reduction in HOAs with shorter reading distance.(F(2,54)=15.6; p < 0.01; ω2 = 0.151) L3 demonstrates lower levels vs L1 and L2, statistically similar . There is a significant difference in total HOAs between all distances, except between 50 and 33 cm (F(1,5 ;42,3)=30,4 ; p < 0.01 ; ω2 = 0,072.) HOAs correlate strongly with pupil diameter (r2 = 0.44, p <0.001), for all lenses. SA seems to vary vs lens type. L3 generates less SA than L1 and L2, but this is not statistically significant. (F(1.5; 41.6)= 3.0; p = 0.07). SA is significantly reduced for all distances except between 50 and 33 cm (AS: F(1.9; 49.3)=24.6; p < 0.01; ω2 = 0.04.) For C, the lens influences the results (F(1,6 ;43,8)=8,7; p < 0.01; ω2 = 0,13. ) L2 has lower levels than L1 and L3, the latter two being statistically similar.
Conclusions :
Lens design and reading distance influence the levels of aberrations induced in the eye. In terms of design, the relationship of the add area vs. the pupil seems to be more important than the add power itself. For distance, it seems that reading at 20 cm reduces aberrations considerably. These results may influence how soft multifocal lenses are designed and used in a young adult myopic population.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.