Abstract
Purpose :
To evaluate the effects of single-vision (SV) & multifocal (MF) contact lenses (CL) on the horizontal (H), oblique (O) & vertical (V) peripheral refraction (PR) & aberration profiles.
Methods :
Forty myopic participants [24.2 yr ± 2.4, 65% F, SE:-0.5 to -4.5D] were fitted randomly with the following lenses: 6 SV’s [AirOptix, Biofinity, Clariti, Proclear, Night & Day and Oasys] and 9 MF’s [Acuvue bifocal, AirOptix, Purevision in low & high adds and MiSight]. The PR profiles across H, O and V meridians, spanning visual field angles from -50° to +50° in 10° steps, were measured with BHVI-EyeMapper, for all lens types at +1D and -3D target vergences. Four repeats were performed with fellow eye occluded. Analysis was done at 4mm pupil. Relative PR (RPR) are reported.
Results :
At +1D vergence, with exception of Night & Day SV (M=-0.31D), all SVCLs produced a hyperopic shift in H-RPR; Biofinity SV produced the steepest drift (M=0.27D). The RPRs remained myopic for all SVCLs in the O & V meridians, where Night & Day SV produced greatest (M=-0.52D) and Biofinity produced the least myopic shift (M=-0.16D). All MFCLs, except MiSight (M=-0.89D), produced hyperopic shifts in the H, O and V meridians (M range 0.06 to 0.44D). In all meridians, the RPR patterns observed at +1D vergence were maintained at -3D target vergence. Regardless of the lens type or accommodative state, J0 and J45 became increasingly more negative for the H & O meridians, respectively. Along the V meridian, J0 became increasingly more positive as a function of field eccentricity. In H & V meridians, magnitude of J45 was relatively insignificant. All lenses measured negative spherical aberration (range: -0.004 to -0.098µm), on-axis, except MiSight and Night & Day which measured positive spherical aberration (range: 0.02 to 0.086µm).
Conclusions :
In the H meridian, only Night & Day SV and MiSight produced peripheral myopic shifts. Remaining lenses produced low to moderate levels of peripheral hyperopia (PH). In the O & V meridians, as the baseline RPR profiles were already in the myopic direction, none of the test lenses produced significant levels of PH. In the light of PH theory, we speculate that some lenses that reduced PH in the H meridian may offer a therapeutic benefit. However, whether myopic defocus in the O & V meridians (at baseline & with most test lenses) can offer a stop signal to myopia progression needs further investigation.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.