Light disturbance analysis in the controlled randomized clinical trial MiSight® Assessment Study Spain (MASS)

Abstract

Purpose: To evaluate the perception of light disturbances (LD) in children wearing Dual Focus (DF) MiSight® contact lenses (CLs) for myopia control compared with children wearing single vision spectacles (SV).

Methods: This was a randomized, controlled clinical trial involving subjects aged 8-12 with myopia of -0.75 to -4.00D and astigmatism <1.00D allocated to MiSight^® study CLs group or control group wearing SV. LD was determined at baseline, 12 and 24 months visit with a validated device, Light Disturbance Analyzer (LDA) to determine the shape, size and regularity of the LD phenomena with parameters of Light Disturbance Index (LDI) Best Fit Circle (BFC) and Standard Deviation between LD and BFC (BFC_Irreg.SD).

Results: 74 children completed the study, 41 in the CL group and 33 in the SV group. SV group didn´t show any significant differences between monocular and binocular LD measurements throughout the study. Binocular BFC_Radius was smaller at 24 months visit compared with 12 month visit (p < 0.05) and for BFC_Irreg.SD was significantly smaller at 24 month visit compared with baseline (p < 0.05). In MiSight^® group, binocular and monocular LDI, BFC_Radius and BFC_Irreg.SD measurements didn't show any significant change between 12 and 24 month visits (p > 0.05). However, monocular BFC_Irreg. as well as monocular and binocular BFC_Irreg.SD showed a significant decrease at 24 month visit compared with 12 month visit.

Conclusions: DF lenses increase the monocular light disturbance perception compared with a single vision spectacle correction. However, this effect decreased over the follow-up time and presented a significant binocular attenuation effect.

Keywords: Children; Dual focus contact lenses; Light disturbance.