Retinal Arteriolar Abnormalities and CV Mortality
Condition: Cardiovascular Diseases; Heart Diseases; Cerebrovascular Disorders; Coronary Disease
MeSH terms: Cerebrovascular Disorders; Cardiovascular Diseases; Heart Diseases; Coronary Disease
Study type: Observational

Summary: 
      To determine whether retinal arteriolar changes (generalized narrowing, focal narrowing and
      arterio-venous nicking) and retinopathy were associated with 10-year stroke-and ischemic
      heart disease-related mortality.
    

Detailed description: 
      BACKGROUND:

      Blood vessels in the retina of the eye provide a valuable window for evaluating
      quantitatively small vessel arteriosclerosis (arteriolar narrowing, arterio-venous nicking
      and arterio-to-venule ratio (AVR)). Previous studies have suggested that these optic fundi
      vascular parameters may be useful measures of generalized vascular disease and may have
      important prognostic implications. This study addressed this issue in a quantitative way
      using an established cohort with previously acquired fundic photographs. The study addressed
      an important public health problem with findings that may identify at-risk patients who would
      benefit from earlier intervention.

      The established cohort was from the Beaver Dam Eye Study cohort, a well-characterized
      population of predominantly white persons aged 43-86 years at the baseline in 1988-1990. The
      cohort was originally evaluated in 1988-1990 with routine clinical and laboratory evaluation
      plus high-quality optic fundi photos. The population had been followed over a 10-year period
      with identified deaths from ischemic heart disease or stroke.

      DESIGN NARRATIVE:

      This was a population-based case-cohort study to determine whether retinal arteriolar changes
      (generalized narrowing, focal narrowing and arterio-venous nicking) and retinopathy were
      associated with 10-year stroke-and ischemic heart disease-related mortality. The study
      population was selected from participants of the Beaver Dam Eye Study, a well-characterized
      population of predominantly white persons aged 43-86 years at the baseline examination in
      1988-90. Cases were defined as participants who had died from either stroke or ischemic heart
      disease since the baseline examination. Three participants per case were selected from the
      cohort at baseline as controls, matched on gender and 5-year age intervals to cases. Focal
      arteriolar narrowing, arteriovenous nicking and retinopathy were graded to baseline using a
      standardized photographic grading protocol. To evaluate generalized arteriolar narrowing, a
      method modified from the Atherosclerosis Risk in Communities study was used. Retinal
      photographs were digitized and processed using a high-resolution scanner. Retinal arteriole
      and venule widths were then measured with the help of a computer program based on pixel
      density contrast between the vessel and the background retina. Finally, the average width of
      the arterioles was summarized as a retinal arteriole to venule ratio (AVR). Standard
      case-control methodology were applied to calculate the relative odds of association between
      generalized retinal arteriolar narrowing (using different categories of AVR) and other
      changes with stroke-and ischemic heart disease-related mortality. Logistic regression models
      controlling for potential confounders (e.g., blood pressure, serum lipid levels) were
      employed to evaluate the independent association between retinal arteriolar characteristics
      and stroke- and ischemic heart disease mortality.
    

Observational model: Case-Control
Time perspective: Retrospective
Sampling method: Non-Probability Sample
Study population: 
        The Beaver Dam Eye Study cohort was first identified by a private census of the city of
        Beaver Dam, Wisconsin from September 15, 1987 to May 4, 1988, was examined from 1988-90
        (baseline examination), and re-examined in 1993-95 and 1998-2000. The baseline examination
        formed the population for both cases and controls. Cases were defined as study participants
        who had died since the baseline examination from stroke or ischemic heart disease. Three
        participants per case were selected from the entire cohort at baseline as controls, age and
        sex matched to cases, irrespective of vital status. No participants were recruited
        specifically for this study.