Power profiles of centre–distance multifocal soft contact lenses

Abstract

Purpose Centre‐distance multifocal contact lenses (MFCLs) for myopia control are thought to slow myopia progression by providing both clear foveal vision and myopic defocus. Characterising the power profile of lenses is important to understanding their possible effects on retinal defocus when worn. The power profiles of three commercially available MFCLs were determined. Methods Three centre‐distance MFCL designs were studied: Biofinity Multifocal D +2.50 add (comfilcon A), Proclear Multifocal D +2.50 add (omafilcon A), and NaturalVue Multifocal (etafilcon A). Two lenses each in power from −1.00D to −6.00D in 1D steps were stored in ISO 18369‐3:2017 standard phosphate buffered saline for 24 h. Optical power profiles were measured in a wet cell with the SHSOphthalmic profiler accounting for centre thickness and manufacturer‐reported material refractive index. Sagittal power maps from the SHSOphthalmic were exported, and custom MATLAB code was used to generate power profiles by averaging along the vertical and horizontal meridians. One‐way anova with Tukey’s HSD post‐hoc t‐tests were used to analyse maximum add power by lens design. Results Plus power increased out from the lens centre for all three MFCLs. Power profiles of Biofinity D and Proclear D MFCLs show three distinct areas within the optic zone; the distance zone (from lens centre to about 1.6 mm radius), intermediate zone (about 1.6 mm radius to 2.1 mm) and near zone (about 2 mm radius to 4 mm). For NaturalVue MFCLs, plus power starts increasing almost immediately from the lens centre, reaching maximum measured mean plus power at a radius of 2.7 mm. From 2.7 mm to 3.0 mm, there was a decrease in plus power, which was then generally maintained out to the optic zone edge. Across all lens powers, maximum add power was highest with the NaturalVue MFCL (+3.32 ± 0.44D), then Proclear D (+1.84 ± 0.28D) and Biofinity D (+1.47 ± 0.34D) MFCLs (all p < 0.04). Add power peaked at different locations for different lens powers and designs. Conclusions Power profiles of MFCLs vary based on lens design and power. These power profiles are consistent with reported myopic and hyperopic changes in peripheral refraction with MFCLs and provide some explanation for reported differences in peripheral refraction with these MFCLs. Further work is needed to determine whether these power profile differences influence myopia progression.

Multifocal contact lens design, not addition power, affects accommodation responses in young adult myopes

“…37 The NaturalVue lens is indicated to have effectively no central spherical optical zone, with relative plus power increasing almost immediately from the lens centre. 29,30 There are little data available for comparison with the accommodative instability results found here. One study found that a centre-distance MFCL had higher microfluctuations than an SV lens.…”

“…Four commercially available MFCL lens types were used: MiSight concentric (+2.00 D add) (MS), Biofinity centre distance, continuous aspheric periphery with a +1.50 D (CD1) and a +2.50 D (CD2) add (all Coopervision, coopervision.com) and NaturalVue aspheric (Visioneering Technologies, vtivision.com) (NVue) which is reported by the manufacturers to be a ‘single high add’ and reaches a maximum relative plus power of +3 D to 5 D by 2.75 mm to 2.9 mm semi‐diameter ( Figure ) 29,30 . Each MFCL lens has a single base curve and single diameter, and all have been investigated for myopia control efficacy in children 8,31–34 .…”

“…com) and NaturalVue aspheric (Visioneering Technologies, vtivision.com) (NVue) which is reported by the manufacturers to be a 'single high add' and reaches a maximum relative plus power of +3 D to 5 D by 2.75 mm to 2.9 mm semi-diameter (Figure 1). 29,30 Each MFCL lens has a single base curve and single diameter, and all have been investigated for myopia control efficacy in children. 8,[31][32][33][34] One SVD CL was used for comparison purposes: Proclear lens (Coopervision) (SV).…”

Contrast Sensitivity with Center-distance Multifocal Soft Contact Lenses

“…19 The complete power profiles of the MiSight, Biofinity Multifocal D, and NaturalVue Multifocal have been previously published. 9,20 The MiSight lens has a centerdistance concentric ring design. The central 2-mm radius is for distance vision and is surrounded by rings of alternating near and distance zones.…”

The use of autorefractors using the image‐size principle in determining on‐axis and off‐axis refraction. Part 2: Theoretical study of peripheral refraction with the Grand Seiko AutoRef/Keratometer WAM‐5500

“…The lens was based on the NaturalVue contact lens (VTI, vtivision.com) which has an increase in sagittal power by approximately 4 D at a diameter of 6 mm. 20,21 It has a front surface with a central zone apical radius of curvature of 7.72 mm, matching that of the Navarro anterior cornea, but with conic asphericity Q = +0.753. A peripheral zone beyond a 6 mm diameter was continuous with the central zone, but was spherical with a 7.72 mm radius of curvature.…”