The present study addresses the accommodative response and its dependence on the type of optical correction used. The results are discussed relative to their possible implications for myopia progression and visual fatigue.
The accommodative response has been investigated owing to its possible relationship with the onset and progression of myopia and visual fatigue. This study explored the influence of wearing soft contact lenses in comparison with spectacles in terms of magnitude and variability of accommodation. In addition, we analyzed the intersession and intermethod repeatability.
Dynamic accommodative response was recorded during 30-second epochs, at five different distances (50, 40, 33, 25, and 20 cm), in 21 individuals (mean refractive error ± SD, −0.79 ± 1.39 D) while wearing either soft contact lenses or spectacles on two different days. To assess repeatability, a second identical intervention was conducted.
Higher lags of accommodation were obtained with the use of soft contact lenses in comparison with the spectacle condition (P = .04, partial η2 [ηp2] = 0.204), and similarly, a higher variability of accommodation at near distances was found during the soft contact lens measurement (P < .001, ηp2 = 0.647). There was a strong intersession repeatability at all the distances tested for both optical correction methods.
The higher accommodative lag and fluctuations found while wearing soft contact lenses in comparison with spectacles may help to understand the mechanisms underlying myopia progression and asthenopia. These findings may be also considered when testing the accommodative response in research settings. Our test-retest design confirmed that there is a very good intersession repeatability for all the distances in both optical correction methods.
1Department of Optics, University of Granada, Granada, Spain
2Ophthalmic Research Group, School of Life and Health Sciences, Aston University, Birmingham, United Kingdom
Submitted: February 14, 2018
Accepted: March 29, 2019
Funding/Support: None of the authors have reported funding/support.
Conflict of Interest Disclosure: None of the authors have reported a financial conflict of interest.
Study Registration Information: IRB approval: 438/CEIH/2017.
Author Contributions and Acknowledgments: Conceptualization: RJ, BR, LND, JV; Data Curation: BR, JV; Formal Analysis: RJ, JV; Methodology: BR, JV; Project Administration: RJ; Supervision: RJ, LND, JV; Validation: RJ, LND; Writing – Original Draft: RJ, BR, LND, JV; Writing – Review & Editing: RJ, BR, LND, JV.
The authors thank the Servilens Fit and Covers Company (Granada, Spain) for the donation of the contact lens supplies used in this study.
Online date: July 23, 2019