title: Retinal microvascular changes and risk of stroke: the Singapore Malay Eye Study.
abstract: OBJECTIVE
  To examine the relationship between retinal microvascular measures and incident stroke in an Asian Malay population.
  
  
  METHODS
  We conducted a prospective, population-based cohort study of Asian Malay persons 40 to 80 years at baseline. Retinal microvascular signs were assessed from baseline retinal photographs including quantitative retinal microvascular parameters (caliber, branching angle, tortuosity, and fractal dimension) and qualitative retinopathy signs. Incident stroke cases were identified during the follow-up period. Cox proportional-hazards regression and incremental usefulness analysis (calibration, discrimination, and reclassification) were performed.
  
  
  RESULTS
  A total of 3189 participants were free of prevalent stroke at baseline. During the follow-up (median, 4.41 years), 51 (1.93%) participants had an incident stroke event. In Cox proportional-hazards models adjusting for established stroke predictors (age, sex, systolic blood pressure, total cholesterol, low-density lipoprotein cholesterol, smoking, glycosylated hemoglobin, and antihypertensive medication), retinopathy (hazard ratio, 1.94; 95% confidence interval, 1.01-3.72) and larger retinal venular caliber (hazard ratio, 3.28; 95% confidence interval, 1.30-8.26, comparing fourth versus first quartiles) were associated with risk of stroke. Compared with the model with only established risk factors, the addition of retinal measures improved the prediction of stroke (C-Statistic 0.826 versus 0.792; P=0.017) and correctly reclassified 5.9% of participants with incident stroke and 3.4% of participants with no incident stroke.
  
  
  CONCLUSIONS
  Retinal microvascular changes are related to an increased risk of stroke in Asian Malay, consistent with data from white populations. Retinal imaging improves the discrimination and stratification of stroke risk beyond that of established risk factors by a significant but small margin.
authors.affiliation: Singapore Eye Research Institute, Singapore National Eye Centre, Singapore. carol.cheung.y.l@seri.com.sg
authors.forename: Carol Yim-lui
authors.initials: CY
authors.lastname: Cheung
authors.forename: Wan Ting
authors.initials: WT
authors.lastname: Tay
authors.forename: M Kamran
authors.initials: MK
authors.lastname: Ikram
authors.forename: Yi Ting
authors.initials: YT
authors.lastname: Ong
authors.forename: Deidre A
authors.initials: DA
authors.lastname: De Silva
authors.forename: Khuan Yew
authors.initials: KY
authors.lastname: Chow
authors.forename: Tien Yin
authors.initials: TY
authors.lastname: Wong
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D055806:Microvessels / Q000473:pathology / Q000503:physiopathology; D008875:Middle Aged; D011446:Prospective Studies; D012164:Retinal Diseases / Q000150:complications / Q000175:diagnosis / Q000453:epidemiology*; D012171:Retinal Vessels / Q000473:pathology / Q000503:physiopathology; D012307:Risk Factors; D012846:Singapore / Q000453:epidemiology; D020521:Stroke / Q000175:diagnosis / Q000453:epidemiology* / Q000503:physiopathology
keywords: Asian Continental Ancestry Group; epidemiology; retinal vascular imaging; stroke