Abstract
Purpose :
While there is evidence for a relationship between myopia development and near vision, the role of accommodation is unclear. We have been assessing accommodation behavior in subjects wearing multifocal lenses for myopia control. Here, we compare accommodative accuracy in myopes with different correction methods and determine whether biofeedback training can be used to reduce lag and improve outcomes.
Methods :
Using custom-developed eccentric infrared photorefractor software, baseline accommodation responses were taken, and accommodation accuracy was trained with auditory biofeedback at different target distances in subjects wearing (a) trial spectacle lenses (b) habitual single vision soft contact lenses (SVCL), and (c) Biofinity multifocal CL (MFCL, add +2.5D, center-distance, CooperVision). In (a), 15 myopes were assessed (24.5±2.8 yrs; Rx -2.1±0.9D) and (b) and (c) included 19 myopes (21.9±1.7 yrs, Rx -2.5±1.0D). Biofeedback was given for 200s, followed by a 2min-break and a 20s-remeasurement without feedback.
Results :
The baseline lag of accommodation (demand-response) was largest for MFCL and at closer distances (both p<.001). The baseline slope of accommodation stimulus-response functions was significantly different between the MFCL and the trial lenses (p<.01). Microfluctuations during the biofeedback session were greater with SVCL and MFCL than spectacle lenses (p<.001). After training, the lag was significantly reduced (p<.001), particularly for closer targets (p=.035), however, the change in lag differed significantly with correction method (p<.05), with larger lag reductions in trial lens and SVCL wear. The mean slope of the stimulus-response function was also significantly changed after training (p<.001), but varied by the correction method (p<.05). The change in lag and demand were correlated for trial lenses (Pearson R=-0.35, p=.019, two-sided) and SVCL (R=-0.37, p=.004), but not for MFCL (R=-0.02, p=.869).
Conclusions :
Biofeedback training improves accommodation accuracy in young adult myopes in all the correction methods tested. However, accommodation through MFCL was less modifiable, probably because the lenses reduce accommodative demand, and may require more training. Considering that relaxed accommodation at near has been previously reported in children wearing MFCL, possibly reducing treatment efficacy, accommodative training may help improve the MFCL’s myopia control effect.
This is a 2020 ARVO Annual Meeting abstract.