title: Racial differences in retinal vessel geometric characteristics: a multiethnic study in healthy Asians.
abstract: OBJECTIVE
  To investigate potential racial/ethnic differences in retinal vascular geometric parameters in a multiethnic Asian population (Chinese, Malay, and Indian) free of clinical diseases.
  
  
  METHODS
  A series of retinal vascular parameters were measured from retinal photographs using a computer-assisted program following a standardized protocol. Healthy participants were defined as nonsmokers, the absence of diabetes mellitus, uncontrolled hypertension, obesity, stroke, heart disease, glaucoma, and retinopathy.
  
  
  RESULTS
  THERE WERE SIGNIFICANT DIFFERENCES IN MEASUREMENTS OF RETINAL VASCULAR CALIBER, TORTUOSITY, AND FRACTAL DIMENSION AMONG THE THREE ETHNIC GROUPS. IN MULTIPLE LINEAR REGRESSION MODEL CONTROLLING FOR AGE, SEX, BODY MASS INDEX, SYSTOLIC BLOOD PRESSURE, CHOLESTEROL, AND GLUCOSE LEVELS, INDIANS HAD THE LARGEST ARTERIOLAR AND VENULAR CALIBERS (ARTERIOLES [SE]: 158.94 μm [1.00]; venules: 228.26 μm [1.53]), followed by Malays (arterioles: 138.31 μm [0.74]; venules: 204.26 μm [1.13]), and then Chinese (arterioles: 131.20 μm [0.84]; venules: 195.09 μm [1.28]). Chinese had the largest arteriolar and venular tortuosity (arterioles [× $${10}^{5}$$]: 7.20 [0.08] VENULES [ $${10}^{5}$$]: 9.09 [0.10]), and venular fractal dimension (1.244 [0.003]). There were no statistically significant differences in other retinal vascular parameters after correcting multiple comparisons by the method of modified false discovery rate.
  
  
  CONCLUSIONS
  We found that among ethnic groups composed of healthy Chinese, Malay, and Indians, there were statistically significant differences in several retinal parameters. There exist racial influences in retinal vascular parameters and other yet unknown or unmeasured environmental factor or lifestyle habits and genetic variations not related to race that may also contribute to these differences.
authors: Singapore Eye Research Institute, Singapore.
authors: Xiang
authors: X
authors: Li
authors: Wan Ling
authors: WL
authors: Wong
authors: Carol Yim-Lui
authors: CY
authors: Cheung
authors: Ching-Yu
authors: CY
authors: Cheng
authors: Mohammad Kamran
authors: MK
authors: Ikram
authors: Jialiang
authors: J
authors: Li
authors: Kee Seng
authors: KS
authors: Chia
authors: Tien Yin
authors: TY
authors: Wong
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D044466:Asian People / Q000706:statistics & numerical data*; D002681:China / Q000453:epidemiology; D005260:Female; D005654:Fundus Oculi; D006801:Humans; D007194:India / Q000453:epidemiology; D007214:Indonesia / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D012160:Retina / Q000033:anatomy & histology*; D012171:Retinal Vessels / Q000033:anatomy & histology*; D012959:Socioeconomic Factors; D044465:White People / Q000706:statistics & numerical data*
keywords: epidemiology; false discovery rate; retinal vasculature