Purpose: To investigate the changes in neural activity in V1, V2, and V3 visual cortical areas of control participants and amblyopic patients during visual stimulation under four differing visual inputs. Patients and Methods: A total of 14 children with monocular amblyopia and 11 age-matched healthy controls were recruited for the study. A fast meridional retinotopic mapping paradigm was employed to efficiently localize regions of interest (ROIs) within the visual cortex. Four types of visual stimulation were achieved using a spatiotemporally modulating checkerboard paired with anaglyph red-blue glasses: amblyopic or non-dominant eye only (AE), fellow or dominant eye only (FE), balanced dichoptic (BE), and imbalanced-dichoptic stimulation (DE). Results: Amblyopic patients exhibit significantly reduced neural activity across V1, V2, and V3 compared to control participants. DE resulted in the most significant reductions in cortical responses for amblyopes. In the control group, significant differences were observed between AE and BE, FE and BE, and BE and DE, while no significant differences were found between AE and DE. In the amblyopic group, significant differences were identified between AE and DE, FE and DE, AE and BE, FE and BE, as well as between BE and DE. Conclusion: Imbalanced dichoptic stimulation produced the largest and most significant reductions in cortical responses, observed exclusively in the patient group, indicating a suppressive influence from the fellow eye. These exploratory data support the view that imbalanced dichoptic stimulation may offer greater potential for neural response recovery compared to monocular approaches. The experimental protocols and findings reported here provide a comparative framework to inform the development of more effective rehabilitation strategies for children with amblyopia. Keywords: anisometropic amblyopia, fMRI, dichoptic, pediatric
Huang et al. (Wed,) studied this question.