Wavefront aberrations and accommodation in myopes and hyperopes

Abstract

to comparatively investigate accommodation, pseudoaccommodation, and higher-order aberrations in children and young adults with myopia and hyperopia. A total of 39 myopic (the mean error of (-)5.2±1.5 diopters) and 53 hyperopic (the mean error of (+)3.1±1.15 diopters) eyes of 46 patients aged 5-20 years (11.6±0.6 years on average) were enrolled. Examination included evaluation of the objective accommodative response, relative accommodation reserves, pseudoaccommodation volume (calculated as the difference between the (+)3.0-diopter lens that is necessary for cycloplegic reading at a 33-cm distance and the weakest possible plus lens that enables reading), and higher-order aberrations (HOA), particularly the root mean square (RMS) value, vertical and horizontal trefoil, vertical and horizontal coma (coma7, coma8), and spherical aberration (SA). Both objective and subjective parameters of accommodation were reliably lower in myopia as compared to hyperopia, while wavefront aberrations (RMS HOA, vertical trefoil, coma7) and pseudoaccommodation - reliably greater. SA was found to be reliably more pronounced in those myopes, who demonstrated larger volume of pseudoaccommodation. At the same time, there was a mismatch in wavefront parameters of myopes and hyperopes at different levels of accommodation and pseudoaccommodation. In myopic eyes, vertical trefoil decreased down to negative values as the accommodative response improved. In contrast to that, in hyperopic eyes with large volume of pseudoaccommodation, SA decreased below zero. Myopia has been shown to be associated with reduced accommodation parameters as well as stronger HOA and pseudoaccommodation. Wavefront and accommodation parameters interrelations differ in myopic and hyperopic eyes. The nuances revealed should be taken into account when developing correction methods that purposefully influence refractogenesis.