Changes in Accommodation and Ocular Aberration With Simultaneous Vision Multifocal Contact Lenses

Objective: The aim of this study was to evaluate ocular aberration changes through different simultaneous vision multifocal contact lenses (CLs). Methods: Eighteen young-adult subjects with a mean age of 29.8 +/- 2.11 years took part. Changes in accommodative response, spherical aberration (C-4(0)), horizontal coma (C-3(1)), vertical coma (C-3(-1)), and root mean square (RMS) of higher-order aberrations (HOAs, third to sixth orders) were evaluated. Measurements were obtained with a distance-single vision CL and 2 aspheric multifocal CLs of simultaneous focus center-near design (PureVision Low Add and PureVision High Add) for 2 accommodative stimuli (-2.50 and -4.00 D). All measurements were performed monocularly with a Hartmann-Shack aberrometer (IRX-3; Imagine Eyes, Orsay, France). Results: No statistically significant differences were found in accommodative responses to -2.50- and -4.00-D stimuli between the single vision CL and the 2 multifocal CLs. Spherical aberration was found to decrease and become more negative with accommodation for both stimuli with all three CLs. Horizontal coma decreased significantly with accommodation (-2.5- and -4.00-D stimuli) for the distance-single vision CLs (P = 0.002 and P = 0.003). No differences were found in vertical coma Zernike coefficients. The RMS of HOAs was found to decrease only with the single vision CLs for both stimuli (P < 0.01). Conclusions: Data obtained in this study suggest that in young subjects, the multifocal CLs studied do not induce large changes in accommodative response compared with the distance-single vision CLs. Spherical aberration reduced significantly with accommodation.