title: Association of the Fractal Dimension of Retinal Arteries and Veins with Quantitative Brain MRI Measures in HIV-Infected and Uninfected Women.
abstract: The fractal dimension of retinal arteries and veins is a measure of the complexity of the vascular tree. We hypothesized that retinal fractal dimension would be associated with brain volume and white matter integrity in HIV-infected women.
  
  
  
  Nested case-control within longitudinal cohort study.
  
  
  
  Women were recruited from the Brooklyn site of the Women's Interagency HIV study (WIHS); 34 HIV-infected and 21 HIV-uninfected women with analyzable MRIs and retinal photographs were included. Fractal dimension was determined using the SIVA software program on skeletonized retinal images. The relationship between predictors (retinal vascular measures) and outcomes (quantitative MRI measures) were analyzed with linear regression models. All models included age, intracranial volume, and both arterial and venous fractal dimension. Some models were adjusted for blood pressure, race/ethnicity, and HIV-infection.
  
  
  
  The women were 45.6 ± 7.3 years of age. Higher arterial dimension was associated with larger cortical volumes, but higher venous dimension was associated with smaller cortical volumes. In fully adjusted models, venous dimension was significantly associated with fractional anisotropy (standardized β = -0.41, p = 0.009) and total gray matter volume (β = -0.24, p = 0.03), and arterial dimension with mean diffusivity (β = -0.33,.p = 0.04) and fractional anisotropy (β = 0.34, p = 0.03). HIV-infection was not associated with any retinal or MRI measure.
  
  
  
  Higher venous fractal dimension was associated with smaller cortical volumes and lower fractional anisotropy, whereas higher arterial fractal dimension was associated with the opposite patterns. Longitudinal studies are needed to validate this finding.
authors.affiliation: Departments of Neurology, SUNY Downstate Medical School, Brooklyn, NY, United States of America.
authors.forename: Howard A
authors.initials: HA
authors.lastname: Crystal
authors.affiliation: Departments of Medicine, SUNY Downstate Medical School, Brooklyn, NY, United States of America.
authors.forename: Susan
authors.initials: S
authors.lastname: Holman
authors.affiliation: Department of Radiology, NYU Langone School of Medicine, New York, NY, United States of America.
authors.forename: Yvonne W
authors.initials: YW
authors.lastname: Lui
authors.affiliation: Departments of Neurology, SUNY Downstate Medical School, Brooklyn, NY, United States of America.
authors.forename: Alison E
authors.initials: AE
authors.lastname: Baird
authors.affiliation: Departments of Neurology, SUNY Downstate Medical School, Brooklyn, NY, United States of America.
authors.forename: Hua
authors.initials: H
authors.lastname: Yu
authors.affiliation: Department of Ophthalmology, University of Wisconsin School of Medicine, Madison, WI, United States of America.
authors.forename: Ronald
authors.initials: R
authors.lastname: Klein
authors.affiliation: Departments of Neurology, SUNY Downstate Medical School, Brooklyn, NY, United States of America.
authors.forename: Diana Marcella
authors.initials: DM
authors.lastname: Rojas-Soto
authors.affiliation: Departments of Neurology, SUNY Downstate Medical School, Brooklyn, NY, United States of America.
authors.forename: Deborah R
authors.initials: DR
authors.lastname: Gustafson
authors.affiliation: Department of Neurological Sciences, Rush University School of Medicine, Chicago, IL, United States of America.
authors.forename: Glenn T
authors.initials: GT
authors.lastname: Stebbins
mesh_terms: D000328:Adult; D001158:Arteries / Q000000981:diagnostic imaging; D001921:Brain / Q000000981:diagnostic imaging*; D016022:Case-Control Studies; D005260:Female; D017709:Fractals; D015658:HIV Infections / Q000000981:diagnostic imaging*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D012171:Retinal Vessels / Q000000981:diagnostic imaging*; D014680:Veins / Q000000981:diagnostic imaging