To describe outer retinal structure in Best vitelliform macular dystrophy (BVMD) patients using spectral-domain optical coherence tomography (SD-OCT) and correlate these RESULTS with best corrected visual acuity (BCVA) and patient age.Retrospective cross-sectional study.Patients with molecularly confirmed BVMD were compared to normal control subjects (NC). Complete clinical evaluation was performed including BCVA, fundus photography, SD-OCT and fundus auto-fluorescence. SD-OCT images were analyzed to determine the stage of the lesion, the central macular thickness (CMT), the foveal outer nuclear layer (ONL) thickness, and tomographic structural changes.Forty-two BVMD patients (42 eyes) with a molecular diagnosis and 42 NC (42 eyes) were included. Clinical stages (Gass clinical classification) were distributed as follow: 4.8% for stage 1, 23.8% for stage 2, 16.6% for stage 3, 45.2% for stage 4 and 9.5% for stage 5. The presence of subretinal fluid and vitelliform material was noted in 76% and 79% of the BVMD eyes examined, and was not associated with BCVA modification (P=0.758 and P=0.968, respectively). The median ONL thickness was significantly lower compared to the control group (P<0.001). BCVA was significantly correlated with stage (R=0.710; P<0.01), age (R=0.448; P<0.01), CMT (R=-0.411; P<0.01) and ONL thickness (R=-0.620; P<0.01). The disruption of the external limiting membrane and the ellipsoid zone was associated with a decreased BCVA (P<0.001 for both). Among the 32 eyes with subretinal detachment, the photoreceptor outer segment (PROS) length was significantly correlated with BCVA (R=-0.467; P<0.01) and ONL thickness (R=0.444; P= P<0.01).This study demonstrates the correlation between BCVA, age and SD-OCT features in BVMD patients. The ONL thickness as well as PROS length are relevant functional correlates and outcome measures to follow photoreceptor impairments and disease progression.