Morphologic changes in the visual cortex of patients with anisometropic amblyopia: a surface-based morphometry study

Minglong Liang,Bing Xie,Jian Wang,Hong Yang,He Xiao,Xuntao Yin

doi:10.1186/s12868-019-0524-6

Abstract

BackgroundAmblyopia is generally considered a neurodevelopmental disorder that results from abnormal visual experiences in early childhood and may persist to adulthood. The neural basis of amblyopia has been a matter of interest for many decades, but the critical neural processing sites in amblyopia are not entirely understood. Although many functional neuroimaging studies have found abnormal neuronal responses both within and beyond V1, few studies have focused on the neurophysiologic abnormalities in the visual cortex from the viewpoint of potential structural reorganization. In this study, we used a well-validated and highly accurate surface-based method to examine cortical morphologic changes in the visual cortex using multiple parameters (including cortical thickness, surface area, volume and mean curvature).ResultsThe cortical thicknesses of the bilateral V1, left V2, left ventral V3, left V4 and left V5/MT+ in patients were significantly thinner than that in controls. The mean curvature of the bilateral V1 was significantly increased in the patients compared with the controls. For the surface area and gray matter volume, no significant differences were found between patients and controls in all region of interests. The cortical thicknesses of the bilateral V1 were both negatively correlated with the amount of anisometropia. No significant correlations were found between any other surface parameters and clinical variables.ConclusionIn addition to cortical thickness, the altered mean curvature of the cortex may indicate neuroanatomic impairments of the visual cortex in patients with anisometropic amblyopia. Moreover, the structural changes were bilateral in the primary visual cortex but were unilateral in the secondary and more senior visual cortex.

Highlights

Amblyopia is generally considered a neurodevelopmental disorder that results from abnormal visual experiences in early childhood and may persist to adulthood
The corrected visual acuity of the amblyopic eye was significantly lower than that of the fellow eye, whereas there was no significant difference in cVA between the dominant and nondominant eyes in the controls
Correlation The cortical thicknesses of the bilateral V1 were both negatively correlated with the amount of anisometropia in the patients (Fig. 2)

Summary

Introduction

Amblyopia is generally considered a neurodevelopmental disorder that results from abnormal visual experiences in early childhood and may persist to adulthood. The neural basis of amblyopia has been a matter of interest for many decades, but the critical neural processing sites in amblyopia are not entirely understood. Amblyopia is a developmental disorder of vision that is believed to follow from abnormal binocular interactions or visual deprivation during early life [1]. It is typically divided into different categories based on the eye disorder responsible for disrupting visual development, and anisometropic amblyopia is one of the most common types [2]. In the past few decades, significant abnormalities have been found that promoted our understanding of the neural mechanisms of amblyopia, but the critical neural processing sites in amblyopia remain unclear. Several resting-state fMRI studies have found altered functional

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Discussion

Conclusion