Effects of blue-tinted lens defocus on myopia susceptibility in mice

Purpose : The mechanisms underlying refractive development and myopia remain elusive. One hypothesis is that alterations in color cues received by the retina through characteristics of longitudinal chromatic aberration (LCA) may signal eye growth (Rucker, 2013). The purpose of this work is to investigate how blue-tinted lenses affect myopic defocus in wild-type mice. Methods : C57BL/6J mice received a monocular, blue-tinted, -10 diopter (D) lens (X-Cell Specialty Contacts, Duluth, GA) (n=10-15) at post-natal day 21 (P21). Age-matched control mice did not wear a lens (n=10-15). Measurements of refractive error, corneal curvature, and ocular biometry were taken weekly until P49, using photorefraction, keratometry, and spectral-domain optical coherence tomography (SD-OCT), respectively. A two-way repeated ANOVA was used to determine significant difference between groups across time. Holm-Sidak post-hoc comparisons were used to make specific comparisons. Results : Mice with blue-tinted lens defocus showed significant myopic shifts compared to their untreated littermates (mean shift in refractive error ± SEM, goggled-contalateral eye, at P28: -3.0172 ± 0.446; at P35: -4.63 ± 0.420; at P42: -6.7764 ± 1.59, p<0.05). There were no significant changes in corneal curvature or ocular biometry in either group. Conclusions : Blue-tinted lenses likely altered the wavelengths of light that reached the retina through properties of LCA. Interestingly, blue-tinted lens defocus produced greater myopic shifts than the well-characterized form-deprivation response in mice (at P42: -3.426 ± 1.382, p<0.05). Future experiments will compare the response to clear, -10D and blue, plano (0 D) lenses to determine the full extent of LCA contributions to myopia in mice.