Abstract
Purpose :
Myopia progression can be hindered with the use of multifocal lenses. One of the biggest optical differences that can be found amongst multifocal contact lenses is the area of the pupil where the addition is placed (center near vs center distance). Through this study we want to evaluate the optical and visual performance offered by each of these lens modalities.
Methods :
The optical profiles of the lenses Biofinity Monofocal, Biofinity Multifocal 2.5 “D” and 2.5 “N” were obtained with the help of the NIMO instrument. The corresponding Visual Strehl in the Frequency Domain (VSOTF) values were calculated for pupil sizes ranging from 1 to 6 mm by using a customized software developed in MATLAB that applies pupil segmentation techniques. Visual acuities were measured in 5 subjects through focus (15 measurements per condition) binocularly wearing “D” lenses, while wearing one “N” (Non dominant eye) and one “D” (dominant eye) lenses, and while wearing a pair of monofocal lenses. Accommodation was paralyzed with tropicamide 1%. VA measurements were performed for pupil sizes with 2 and 6 mm. Measurements were randomized between subjects to prevent learning/fatigue effects.
Results :
Multifocal contact lenses offer a better optical quality for a wider range of object vergences than monofocal lenses. Under multifocal vision with 2.5 “D” lenses, the amount of optical and visual quality observed in front of the retina is larger than with monofocal lenses (59% multifocal vs 48% monofocal for a 2 mm pupil and 61% vs 48% for a 6 mm pupil). When using a combination of 2.5 “D” and “N” lenses the amount of visual quality found in front of the retina is a 57 % for a 2 mm pupil and a 59% for a 6 mm pupil.
Conclusions :
NIMO results showed the add power was placed in the center of the lens for the “N” lenses and the add power was located on the periphery of the lens in the “D” lenses. All multifocal combinations increased the amount of optical quality available in front of the retina. The best result for myopia progression for 2 and 6 mm is obtained with a binocular use of Biofinity Multifocal 2.5 “D”. Given that using “N” and “D” designs simultaneously introduces differences between the left and right eyes and that this combination does not offer a superior cue to contain myopia progression, we recommend clinicians to use “D” center designs binocularly with patients interested in myopia controlling contact lenses.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.