Abstract
Purpose :
To compare Convergence Insufficiency Symptoms Survey (CISS) findings, phoria, and accommodative lag between single vision and multifocal contact lens wearers with +1.50 add and +2.50 add over three years.
Methods :
The BLINK Study randomly assigned 294 7-11 year old children with -0.75 to -5.00 D spherical myopia, <1.00 D astigmatism, and <1.00 D anisometropia by cycloplegic autorefraction to wear Biofinity (single vision) or Biofinity Multifocal D contact lenses with a +1.50 add or +2.50 add. Participants completed the CISS, accommodative lag at 33 cm, and Modified Thorington phoria measurement at 40 cm during baseline, 2 weeks after initiating contact lens wear (2 week), 1 year, 2 year, and 3 year visits. We fit a repeated measures model with treatment group, visit, and treatment group X visit interaction as predictors.
Results :
There were no statistically significant differences between groups for CISS scores, accommodative lag, or near phoria at baseline (all p≥0.16). The mean CISS scores were higher at baseline than all other visits for all 3 groups (all p<0.001), but there were no statistically significant differences between groups at any visit (all p≥0.22). The accommodative lag was less than baseline at all visits for all 3 groups (all p<0.04) except the lag was similar between baseline and 2 weeks for +2.50 add (p=0.19). The only differences observed between treatment groups were between single vision and +2.50 add at 2 weeks (p<0.001) and 1 year (p=0.002), and between single vision and +1.50 at 2 weeks (p=0.005). The maximum difference between groups in average accommodative lag was never more than 0.33 D. Near phoria was statistically significantly more exophoric after baseline for both add powers (all p≤0.04), but on average never became more than 2.4 prism diopters more exophoric over the three years. The +2.50 add group was more exophoric than the single vision group at all visits after baseline (all p≤0.04), but never more than 2 prism diopters more exophoric on average over three years. See the Table for mean ± SD CISS score, accommodative lag, and phoria for each treatment group at each visit.
Conclusions :
Myopia control with soft multifocal contact lenses does not meaningfully affect phoria, accommodative lag, or subjective reports of binocular vision comfort.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.