Visual Performance and Higher Order Aberrations Obtained With Omafilcon A Dual-Focus and Single-Vision Contact Lens...

The purpose of this study was to assess the visual performance and monochromatic higher-order aberrations (HOAs) obtained while wearing a MiSight dual-focus (DF) contact lenses (CL) in comparison with a single-vision contact lens (SVCL).

A randomized, double-masked, cross-over study was performed. Participants were fitted with a DFCL and a SVCL composed of the same material (omafilcon A) and parameters. Logarithm of the Minimum Angle of Resolution high-contrast (100%) and low-contrast (10%) visual acuity (VA) and contrast sensitivity (CS) for 3, 6, 12, and 18 cycles per degree were measured. Higher-order aberrations were also evaluated using a Hartmann-Shack aberrometer with the CLs on.

Twenty-four subjects (21 females and 3 males) with a mean age of 21.9±1.9 years (range: 18-27) were included. Low-contrast VA was significantly lower with the DFCL regarding the SVCL design (0.39±0.23 vs 0.25±0.18, P=0.002). However, there were no differences in high-contrast VA between both CLs (-0.03±0.10 vs -0.09±0.14, P=0.187). Contrast sensitivity was lower with the DFCL under all spatial frequencies (P≤0.048). Second-, third-, fourth-, and fifth-order aberrations were significantly (P<0.001) higher for the DFCL. There were also significant differences between DFCL and SVCL in defocus (0.87±0.28 vs 0.16±0.35, P<0.001), oblique trefoil (-0.16±0.27 vs -0.01±0.08, P=0.005), vertical coma (0.13±0.17 vs 0.00±0.08, P=0.002), and spherical aberration (0.09±0.11 vs -0.02±0.05, P=0.002).

Visual performance for detecting low-contrast targets is reduced when wearing MiSight DFCL compared with a SVCL with the same material. The main reason might be the induction of second-order and HOAs by the DFCL design.