A morpho-functional study of amblyopic eyes with the use of optical coherence tomography and microperimetry.

Purpose: To determine whether retinal nerve fiber layer thickness (RNFLT), macular thickness, foveal volume, macular sensitivity, and fixation in patients with amblyopia differ between the amblyopic eye and the fellow eye.

Methods: Optical coherence tomography (OCT) and microperimetry (MP-1) were used to evaluate patients with unilateral amblyopia. Patients were divided into 2 groups, those with strabismic amblyopia and those with refractive amblyopia. OCT maps were used to calculate foveal volume, macular thickness, and RNFLT; MP-1 was used to determine macular sensitivity and fixation.

Results: A total of 30 patients were included (13 males; mean age 19.7 years [range, 10-38 years]), 15 in each group. Mean best-corrected visual acuity was 20/35 (range, 20/50 to 20/32) in the amblyopic eye and 20/21 (range, 20/20 to 20/25) in the fellow eye. In both groups, mean foveal volume and RNFLT did not differ significantly between eyes. Only macular thickness in the strabismic group differed significantly between the amblyopic and fellow eyes (P = 0.03). Macular sensitivity was significantly greater in the fellow eye in both groups (strabismic group, P = 0.002; refractive group, P = 0.013), whereas fixation did not change significantly between the amblyopic and fellow eye. RNFLT and macular sensitivity was found to be significantly correlated (strabismic group, r = 0.84, P = 0.002; refractive group, r = 0.66, P = 0.02).

Conclusions: Our data suggest that although RNFLT does not vary between eyes, macular sensitivity is reduced in patients with amblyopia.