Short Term Axial Length Changes with Defocus Spectacles for Myopia Control
15 Pages Posted: 21 Feb 2023
Date Written: February 5, 2023
Purpose. The present study tested short term axial length changes with Lenstar under the use of a simple peripheral plus add spectacle design.
Methods. Subjects for this study were current users of monofocal glasses or contact lenses, aged 18-25 years, with myopic spherical equivalent in the range of -1.00 to -5.00 diopters in both eyes. This study tested subject when using a pair of especial defocus spectacles which have a central zone with the distance myopic correction and a peripheral zone with +3.50 diopter add. The experiment consisted in reading an online book with black letters on white background on a desktop computer in two periods, one with usual spectacles and the second with special defocus spectacles. Before and after these periods, 10 measurements of the axial length of the right eye were made with the Lenstar and were averaged up to three decimals.
Results. Seventeen subjects with a mean age of 22.3+/-5.5 years (13 women) participated in this study. The mean spherical equivalent of their right eye was -2.31+/-1.06 diopters. There was a significant difference of +8.1 microns increased axial length from baseline when reading with the usual prescription during the first 40 min period. When subjects read in the same situation with the defocus spectacle, the axial length significantly returned to baseline measurements, shortening by -10.6 microns.
Conclusion. The decrease in axial length with these spectacles may show a possible effect on axial elongation signals from the choroid. These spectacles could be tested for myopia control.
Funding Information: None.
Declaration of Interests: None of the authors have any proprietary interests or conflicts of interest related to this submission.
Ethics Approval Statement: Subjects gave verbal informed consent to participate in the study using a pair of special myopia control spectacles that were provided free of charge for an experiment that lasted approximately two hours. The study was conducted in accordance with the tenets of the Declaration of Helsinki. The Ethics Committee of the Argentinian Council of Ophthalmology approved the study.
Keywords: myopia control, defocus spectacles, axial length
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