Background Some optic nerve diseases are silent and insidious. Recently, reduced thickness of retinal nerve fibre layer (RNFL) has been associated with increasing body mass index in adults.

Objectives To investigate the association of childhood obesity with RNFL measured by optical coherence tomography imaging.

Methods Ninety‐seven children aged 5–14 years classified according to standard deviation score of body mass index (SDS‐BMI) were included. Parameters of metabolic risk, adipocytokines (leptin, adiponectin) and interleukin‐6 were analyzed. All subjects underwent a comprehensive ophthalmologic examination with direct ophthalmoscopy. Evaluation of RNFL with optical coherence tomography of the head of the nerve was performed.

Results RNFL thickness on the average and inferior, superior and nasal quadrants were decreased in severely obese children (SDS‐BMI > 4) with respect to the other groups. However, no statistically significant association was found between the different groups of children and RNFL thickness in the temporal quadrant. There was a significant inverse correlation of RNFL thickness with adiposity indices (P = 0.016), leptin (P = 0.029) and interleukin‐6 (P = 0.030) in overweight and obese children.