The relationship between retinal nerve fiber layer thickness and carotid intima media thickness in patients with type 2 diabetes mellitus

Abstract

Aims: the aim of the present study was to investigate retinal nerve fiber layer (RNFL) thickness in patients with type 2 diabetes mellitus (T2D) using spectral-domain optical coherence tomography and to evaluate the relationship between RNFL thickness and carotid intima media thickness (CIMT). Methods: This study included 171 patients with T2D (53.2+/-8.8 years) and age matched 61 healthy controls (51.9+/-8.1 years). We evaluated anthropometric and metabolic parameters as well as RNFL and CIMT measurements in patients with T2D and controls. the MannWhitney U test was used to compare the continuous variables and the Chi-square test was used to compare categorical variables. Spearman's rank correlation test was used for calculation of associations between variables. Results: the average RNFL thickness was 84.82+/-11.22 mm in patients with T2D and 92.35+/-8.45 mm in healthy controls (p < 0.001). Mean CIMT values were higher in patients with T2D (0.80+/-0.1 mm) than the healthy subjects (0.72+/-0.1 mm) (p < 0.001). A significant negative correlation was found between age and all quadrants of RNFL. There was a negative correlation between average RNFL thickness and HbA1c (r =-0.176), uric acid (r = -0.145), CIMT (r = -0.190) and presence of carotid plaque (r = -0.193). the superior RNFL thickness was negatively associated with HbA1c (r = -0.175), CIMT (r = -0.207) and carotid plaque (r = -0.176). There was also an inverse correlation between the inferior RNFL thickness and HbA1c (r = -0.187) and carotid plaque (r = -0.157). Conclusion: Thinning of RNFL might be associated with atherosclerosis in patients with T2D. (C) 2014 Elsevier Ireland Ltd. All rights reserved.