Attention-Related-Functional Changes Induced By Imposed Myopia Defocus From Spectacle Lens

Abstract

Purpose : Increasing evidence from a diverse range of animal studies indicate that ocular growth is strongly guided by visual error signals, specifically the optical defocus. To test the hypothesis that myopic defocus signal involves advanced nervous system, we explored short-term myopic defocus induced neuronal changes in healthy human subjects and the difference between myopes and non-myopes.

Methods : A total of 41 normally-sighted subjects (9 emmetropes, 6 low myopes, 16 moderate myopes and 10 high myopes，mean 24±3 years) underwent functional magnetic resonance imaging(fMRI). Subjects wore full refractive correction and +2.00D, +4.00D, +6.00D of myopic defocus in separate, randomized sessions. Over a 7 min session whist looking through full correction or defocus lenses, arterial spin labeling (ASL) perfusion MRI was acquired to obtain quantified regional cerebral blood flow (rCBF).

Results : Using a classical data analysis strategy, we observed that myopic defocus induced significant rCBF increases in 8 cerebral regions when compared with full correction: right precentral gyrus, right superior temporal gyrus, left inferior parietal lobule, left middle temporal gyrus, left middle frontal gyrus, right inferior temporal gyrus, right inferior frontal gyrus and left fusiform gyrus cortex. These cerebral regions were mostly associated with functions of oculomotor response, attention and awareness, contemplating distance and recognition of image. The rCBF increases in some of these 8 cerebral regions were less significant in myopia group than non-myopia group.

Conclusions : Our findings revealed that myopic defocus stimulation could significantly increase attention-related changes in brain regional activity, which suggest some directions for future exploration about the relationship between lens-induced myopia and the central neural system.

This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.

 

Average activation maps resulting from group analysis, showing the increasing of neural activation in myopia defocus relative to clear focus state. Color scale indicates score significance level

 

Active loci of myopia defocus vs. clear focus.