Background/aims To compare the thickness of each retinal layer of amblyopic and fellow eyes in patients with unilateral amblyopia.

Methods Horizontal and vertical spectral-domain optical coherence tomography scans through the fovea were obtained for 20 patients with unilateral amblyopia. The thickness of each retinal layer in the amblyopic eyes was measured at the foveal centre, inner macular locations (a mean of 490 μm and 500 μm superior, inferior, nasal and temporal to the foveal centre) and outer macular locations (a mean of 1490 μm and 1500 μm superior, inferior, nasal and temporal to the foveal centre) and compared with corresponding locations in the fellow eyes.

Results In amblyopic eyes, there was significant thinning of the ganglion cell layer plus inner plexiform layer at all four nasal and temporal macular locations and at the outer superior and inferior locations. Other retinal layers, including the nerve fibre layer, inner nuclear layer, outer plexiform layer and outer nuclear layer, demonstrated significant differences in thickness at several macular locations.

Conclusions These data, obtained using spectral-domain optical coherence tomography, reveal differences between amblyopic and fellow eyes in the thickness of some retinal layers, including a notable difference in the ganglion cell layer plus inner plexiform layer.