title: The relationship between retinal nerve fiber layer thickness and carotid intima media thickness in patients with type 2 diabetes mellitus.
abstract: OBJECTIVE
  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 Mann-Whitney 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 μm in patients with T2D and 92.35 ± 8.45 μm in healthy controls (p<0.001). Mean CIMT values were higher in patients with T2D (0.80 ± 0.1mm) than the healthy subjects (0.72 ± 0.1mm) (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).
  
  
  CONCLUSIONS
  Thinning of RNFL might be associated with atherosclerosis in patients with T2D.
authors.affiliation: Department of Endocrinology and Metabolism Disease, Recep Tayyip Erdogan University Medical School, Rize, Turkey.
authors.forename: Serap Baydur
authors.initials: SB
authors.lastname: Sahin
authors.affiliation: Department of Nephrology, Recep Tayyip Erdogan University Medical School, 53020 Rize, Turkey. Electronic address: drosahin@yahoo.com.
authors.forename: Osman Z
authors.initials: OZ
authors.lastname: Sahin
authors.affiliation: Department of Internal Medicine, Recep Tayyip Erdogan University Medical School, Rize, Turkey.
authors.forename: Teslime
authors.initials: T
authors.lastname: Ayaz
authors.affiliation: Department of Cardiology, Recep Tayyip Erdogan University Medical School, Rize, Turkey.
authors.forename: Zakir
authors.initials: Z
authors.lastname: Karadag
authors.affiliation: Department of Ophthalmology, Recep Tayyip Erdogan University Medical School, Rize, Turkey.
authors.forename: Kemal
authors.initials: K
authors.lastname: Türkyılmaz
authors.affiliation: Department of Family Medicine, Recep Tayyip Erdogan University Medical School, Rize, Turkey.
authors.forename: Ezgi
authors.initials: E
authors.lastname: Aktas
authors.affiliation: Department of Cardiology, Recep Tayyip Erdogan University Medical School, Rize, Turkey.
authors.forename: Mehmet
authors.initials: M
authors.lastname: Bostan
mesh_terms: D001786:Blood Glucose / Q000378:metabolism; D017536:Carotid Artery, Common / Q000000981:diagnostic imaging* / Q000473:pathology; D059168:Carotid Intima-Media Thickness; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000150:complications / Q000175:diagnosis*; D003930:Diabetic Retinopathy / Q000175:diagnosis / Q000209:etiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009412:Nerve Fibers / Q000473:pathology*; D011379:Prognosis; D012165:Retinal Ganglion Cells / Q000473:pathology*; D041623:Tomography, Optical Coherence / Q000379:methods*; D017540:Tunica Media / Q000000981:diagnostic imaging* / Q000473:pathology
chemical_list: D001786:Blood Glucose
keywords: Carotid intima media thickness; Retinal nerve fiber layer thickness; Type 2 diabetes