Body Mass Index and Interocular Asymmetry of Retinal and Choroidal Thickness in Emmetropic and Ametropic Subjects

Objective: To assess the normal range of interocular asymmetry in retinal and choroidal thickness in healthy emmetropic (as a control group) and ametropic subjects and to describe its relationship with anthropometric attributes. Methods: A Spectral-Domain Optical Coherence Tomography (SD-OCT) was performed on 586 patients to measure the thickness of the retina and choroid at the fovea as well as at 1, 2 and 3 mm nasally, temporally, superiorly, and inferiorly. In 95% confidence intervals, absolute interocular differences were calculated to determine the normal range of asymmetry and its relationship to Body Mass Index (BMI). Results: There was a statistically significant interocular difference in the choroidal thickness at 3 mm distance from the center inferiorly (Standardized Mean Difference (SMD): -17.33, 95% Confidence Interval (CI): -29.60 to -5.07 µm, P < 0.001) in the control group, and in the macular thickness at 2 mm distance from the center superiorly (SMD: -9.76, CI: -17.40 to 2.13 µm, P = 0.01) in the myopic group between underweight and overweight individuals. Conclusion: The expanded range of retinal and choroidal thickness asymmetry found in subjects with different BMI grades in the absence of disease is of relevance when exploring these patients for early signs of ocular pathology.