Inclusion Criteria:  Patients with BMI≥32.5Kg/m2； patients with BMI27.5-32.5Kg/m2, combined with metabolic diseases;  Exclusion Criteria:  Patients with pre-existing ocular diseases or visual alterations were excluded to avoid confounding factors related to pre-existing retinal pathology, independent from obesity per se. Patients with dementia, Parkinson's disease, Alzheimer's disease, multiple sclerosis or other severe neurological diseases were also excluded since ophthalmologic parameters may be altered in these conditions. Patients with lens opacities that made impossible the posterior segment examination, or with a refractive error > +5 or <-8 diopters spherical equivalent were also excluded.