Abstract
Purpose :
To investigate the impact on contrast sensitivity function (CSF) with various commercially available myopia control (MC) spectacles and contact lenses (CL). Altered CSF may impact visual function and possibly play a role in MC efficacy, but there is limited research comparing spectacles and CL for MC.
Methods :
Subjects aged 18-35 years were recruited for a randomised non-dispensing study whereby CSF was evaluated monocularly, under standardised photopic conditions for each lens by at least 10 subjects. The lenses included single vision (SV) spectacles, SV CL (Acuvue Moist), MiSight CL, and Miyosmart spectacles (on-axis viewing, and off-axis viewing by lens decentration). For spectacles, all lenses were tested with the subject’s best corrected spherical equivalent (BCSE) in place in a trial frame over the right eye with the left eye occluded. For CL, the BCSE power (vertex distance-corrected) was selected. Gabor patch targets were randomised on a digital monitor at 1 metre. CSF was measured at 1, 3, 6, 10, 15, 20, 24, and 28 cycles per degree (CPD) and assessed using Log contrast sensitivity (CS) by spatial frequency (SF) as well as by the area under Log contrast sensitivity function (AULCSF). Photopic pupil size was captured at each visit using Gaze Tracker 3 (Gazepoint, Canada). A linear mixed model with Bonferroni post-hoc correction was used for analysis between lenses and between SF.
Results :
Fifteen (11 female, 4 male) subjects (mean age: 25.8±5.0 years) with a mean BCSE of -2.08±2.33D (range +0.50 to -7.88D) completed the study. For on-axis viewing, there were no significant differences between lenses for CSF at all SF and with AULCSF. However, CS at 15 CPD was reduced with off-axis viewing with Miyosmart as compared to Miyosmart on-axis (p<0.01), SV spectacles (p=0.01), and Acuvue Moist (p<0.01), and at 20 CPD when compared to Acuvue Moist (p<0.01). Pupil size (baseline mean 3.9±0.7mm, range 2.3 to 5.6) was not found to be correlated with CS at any SF (r= -0.3 to 0.23, p>0.18).
Conclusions :
Overall, there was no difference in CS at any SF between SV spectacles and SV CL, or with MC CL or MC spectacles (in primary gaze). However, there was reduction at the mid-high range SFs when viewing through the off-axis portion in Miyosmart. More work is needed to understand the implications of this on overall visual function and the role this may play in the mechanism of MC efficacy.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.