Peripheral optical errors and their change with accommodation differ between emmetropic and myopic eyes

Abstract

The progression of myopia is thought to be controlled by the retinal image quality, but its triggering factors are not yet well known. The differences between the peripheral optics in emmetropic and myopic eyes might explain why some eyes become myopic. The present study further investigates peripheral optical quality and how it is affected by accommodation. The refraction and aberrations of the right eyes of five emmetropes and five myopes were measured using a laboratory Hartmann-Shack wave front sensor, specially designed for peripheral measurements with an open field of view. The off-axis optical quality was assessed in steps of 10 degrees out to +/-40 degrees horizontally and +/-20 degrees vertically for two different states of accommodation (targets at 0.5 D and 4.0 D). As expected, the emmetropes had a higher relative peripheral myopia, that is, more positive c(2)(0) coefficient, than the myopes. The new results of this study are that this well-known difference was found to be asymmetric over the visual field and that it increased with accommodation. This increase was because the relative peripheral defocus profile of the myopes did not show a consistent change between far and near vision, whereas the emmetropes became relatively more myopic in the periphery with accommodation. These findings may indicate a difference between emmetropic and myopic eyes that could be an important clue to understand myopia progression.

Symmetries in peripheral ocular aberrations

“…First, defocus showed large differences between individuals in how it varied with the off-axis angle over the temporal and nasal halves, as earlier noted by Gustafsson and co-workers and Ferree and colleagues [5,26]. Secondly, the higher-order aberrations tended to be larger in the nasal visual field, which can also be seen for astigmatism in Figure 3 and in the figures of references [2,3,21,23].…”

“…These were one laboratory Hartmann-Shack sensor in Murcia, Spain, which has been previously used for peripheral measurements [21,22], and one commercial Hartmann-Shack (COAS-HD-VR) sensor in Kalmar, Sweden, which has been shown to provide repeatable measurements of peripheral aberrations [23]. In total, there were 22 subjects.…”

An exploratory study of temporal integration in the peripheral retina of myopes

“…According to Shen and colleagues soft contact lenses do not have a consistent effect on peripheral relative blur 30 whilst others showed that axial correction increases the precision of offaxis refractive error measurements. 31 However, soft contact lens have an effect on relative peripheral refraction (field curvature) that we discuss below. Thus, during measurements participants with myopia were compensated with a spherical contact lens (Focus Dailies®, Ciba Vision Corporation) to correct on-axis refractive error, the power of the lens was the spherical equivalent.…”

The Determinants of Early Refractive Error on School-Going Chinese Children

“…The progression of myopia is thought to be controlled by the retinal image quality, but its triggering factors have not been yet well known (Lundstrom, Mira-Agudelo, & Artal, 2009). In a large number of studies, children with myopic parents are more likely to have myopia than those without myopic parents (Guggenheim, Kirov, & Hodson, 2000;Mutti et al, 2002;Mutti & Zadnik, 1995;Saw, Nieto, et al, 2001; M. M. Wu & Edwards, 1999;Young, 2009).…”