BOLD responses to different temporospatial frequency stimuli in V1 and V2 visual cortex of anisometropic amblyopia

Eur J Ophthalmol. 2013 Mar-Apr;23(2):147-55. doi: 10.5301/ejo.5000211.

Abstract

Purpose: Functional magnetic resonance imaging (fMRI) is the most advanced neuroimaging technique. The aim of this study was to investigate the blood oxygenation level-dependent (BOLD) of V1 and V2 visual cortex in anisometropic amblyopia with fMRI and explore the neural mechanism of amblyopia.

Methods: fMRI was performed with a 3.0-T MRI scanner during reversal checkerboard visual stimulation with different spatial frequencies (SF) of 0.4, 2, and 8 cpd in 2 states of temporal frequencies (TF) of 6 Hz and 8 Hz in a group of patients with anisometropic amblyopia (n=5) and a group of normal observers (n=4). Data were processed by SPM software offline. Responses of different eyes were compared in different conditions.

Results: The BOLD signal magnitude in V1 and V2 visual cortex of amblyopic eyes was significantly lower than the fellow eyes with anisometropic amblyopia at low SF (0.4-2 cpd) (p<0.05), but it was significantly higher than the fellow eyes at high SF (8 cpd) (p<0.05). The BOLD signal magnitude in V1 and V2 visual cortex of amblyopic eyes was significantly lower than the nondominant eyes in normal subjects in all conditions (p<0.001).

Conclusions: There are cortical deficits in V1 and V2 visual cortex of anisometropic amblyopia, which may be useful for selecting an optimum stimulus at proper temporospatial frequency.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Amblyopia / physiopathology*
  • Female
  • Humans
  • Magnetic Resonance Imaging
  • Male
  • Oxygen / blood*
  • Photic Stimulation
  • Refraction, Ocular / physiology
  • Visual Acuity / physiology
  • Visual Cortex / physiopathology*
  • Young Adult

Substances

  • Oxygen