Correlation of the measurements of optical coherence tomography and diffuse tension imaging of optic pathways in amblyopia

The aim of this study was to investigate whether a correlation exists between optical coherence tomography (OCT) of retina and diffusion tensor imaging (DTI) of the optic pathway measurements. All subjects underwent OCT measurements of optic nerve head, retinal nerve fiber layer, and macula. Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values of optic pathways were analyzed using DTI. Prechiasmatic FA values were significantly decreased in unilateral amblyopic group in both affected and sound fellow eyes (p = 0.019 and 0.013), but not in bilateral amblyopic group (p = 0.221) when compared with the control group. ADC values were significantly greater in sound eye in unilateral amblyopic group in prechiasmatic and postchiasmatic regions (p = 0.001 and 0.049). ADC values were also significantly greater in bilateral amblyopic group in postchiasmatic region (p = 0.037). There were no significant differences between the affected eye and sound eye side DTI measurements. There was no significant correlation between prechiasmatic DTI and OCT measurements in affected and sound eyes of unilateral amblyopia group. DTI results demonstrated that there is a functional underdevelopment of the anterior and posterior visual pathways in both affected and sound eye of unilateral amblyopic patients. Significantly reduced FA values in prechiasmatic region where OCT values of retina were normal can be explained by possible micro-structural changes.