Correlation between body mass index and corneal thickness in emmetropic subjects

Background: Body mass index (BMI) uses a person’s weight and height to estimate body fat as an indication of an individual’s health status. Several studies have suggested that BMI (calculated as weight in kilograms divided by the square of height in metres) was related to central corneal thickness (CCT) in non-emmetropic subjects; however, there is limited information about the possible correlation between BMI and the CCT in healthy emmetropic eyes. Aim: This study aimed to investigate the correlation between CCT and BMI in healthy emmetropic eyes. Setting: The study was performed by the GIAVAL research group of the Faculty of Medicine and Odontology, University of Valencia, Spain. Methods: The emmetropic eyes of 81 (mean age ± standard deviation [s.d.]: 21.8 ± 1.8 years) adults were included in this retrospective study. Ophthalmic CCT measurements were measured using non-invasive scanning-slit corneal topography. The height and weight of all subjects, using a standard tape measure and weight scale, were recorded, and BMI was calculated. Results: There were no significant correlations between CCT and the BMI values in the 81 emmetropic adults (r = 0.16; p = 0.135), between CCT values and BMI (18.5 to < 25) (r = 0.21; p = 0.724) and between CCT values and BMI (25.0 to < 30) (r = –0.28; p = 0.465). In addition, no correlation occurs between the CCT values and BMI in both women (r = 0.22; p = 0.160) and men (r = –0.14; p = 0.412). A weak negative correlation does seem to present with age and CCT (r = –0.29; p < 0.05). However, the coefficient of determination suggests that only 8% (r = 0.08) of the variance is shared between age and CCT. Conclusion: The results do not show a correlation between CCT and BMI values in young subjects with healthy emmetropic eyes. Contribution: This study has revealed that the CCT values are not correlated with the BMI values in healthy emmetropic eyes of young subjects without obesity. In addition, normative data for the CCT in normal anatomic eyes has been reported, which will serve as a baseline for future comparative studies in non-emmetropic eyes.