Retinal nerve fibre layer thickness is reduced in metabolic syndrome

Aims To investigate retinal nerve fibre layer (RNFL) thickness in people with metabolic syndrome (MetS) and healthy controls. Methods A cross‐sectional study was performed from March 2014 to January 2016. All participants underwent anthropometric and serological biochemical measurements, ophthalmological examination, and spectral‐domain optical coherence tomography (SD‐OCT). Individuals with elevated intraocular pressure, glaucoma, diabetic retinopathy and other ocular disorders were excluded. T‐test, Chi square and general linear models were used to analyse the data. Results In total, 278 eyes from 139 participants were investigated [median (interquartile range) age: 37 (32−43) years]. RNFL thickness was lower in the nasal superior (107.8 ± 19.5μm) and temporal superior (135.7 ± 18.9μm) sectors in MetS group compared with the control group (114.6 ± 22.4 μm, P = 0.013 and 140.7 ± 18.2 μm, P = 0.027, respectively). After multiple adjustments for age, gender and the side of the examined [right (OD)/left (OS)] eye, MetS was independently associated with a lower RFNL thickness in the nasal superior (β = 0.20, P = 0.009) and temporal superior (β = 0.14, P = 0.048) sectors. RNFL thickness was significantly reduced in participants with higher numbers of metabolic abnormalities, independent of age, gender and the side of the examined eye (P = 0.043). Conclusion Our findings demonstrate that MetS is independently associated with reduced RNFL thickness, suggesting that neurodegeneration is implicated in pathogenesis of MetS. What's new? This is the first study to compare retinal nerve fibre layer thickness among people with metabolic syndrome and healthy controls. Metabolic syndrome was independently associated with reduced retinal nerve fibre layer thickness. Thinning of the retinal nerve fibre layer in people with metabolic syndrome was significant in the nasal superior and temporal superior sectors. Neurodegeneration may constitute a feature of metabolic syndrome.