Retinal vasoreactivity as a marker for chronic ischemic white matter disease?
The cerebral microvasculature cannot be easily studied non-invasively. Because the retina and brain share embryological, anatomical and physiological similarities, studies of retinal blood vessels may prove to be useful as a surrogate marker for cerebrovascular disease. In epidemiological studies abnormal retinal arteriovenous ratios (AVRs) predict the risk of stroke and vascular dementia. However, the association between retinal vasoreactivity, cerebral small vessel ischemic disease, and cerebral blood vessel function remains unknown.


OBJECTIVE
To examine (1) the association between cerebral ischemic white matter disease (WMD) and retinal microvessel behavior and (2) the relationship between retinal blood vessel reactivity and measures of cerebrovascular function.


METHODS
Cohort study of 12 patients with ischemic WMD and 14 healthy controls. Retinal vasoreactivity was measured following high frequency flicker light stimulation. Middle cerebral artery (MCA) vasoreactivity was measured using transcranial Doppler ultrasound (TCD). Magnetic resonance imaging scans (MRIs) were reviewed for evidence of ischemic WMD.


RESULTS
Patients with ischemic WMD had attenuated retinal venous (2.2% ± 0.27 SD, vs. controls 6% ± 0.7 SD, p=0.002, CI 95%) and arterial (1.9% ± 0.8 SD, vs. controls 4.9% ± 0.8 SD, p=0.004, CI 95%) vasoreactivity compared to controls. An attenuated retinal venous light flicker response was associated with a significant decrease of MCA vasoreactivity (r=0.45, p=0.05, CI 95%). Decreased AVRs, an indicator for altered retinal vessel architecture in patients with cerebral chronic ischemic WMD, were also significantly correlated with dysfunction of cerebral vasoreactivity (r=0.69, p=0.001, CI 95%).


CONCLUSIONS
In this study functional and structural impairment of the retinal microvasculature were associated with ischemic WMD and measures of cerebral vascular function. Microvascular dysfunction in the eye may predict cerebral small vessel disease, but validation by larger studies is needed.
Department of Neurology, Penn State College of Medicine, Hershey, PA, USA. kbettermann@hmc.psu.edu
Kerstin
K
Bettermann
Julia E
JE
Slocomb
Vikram
V
Shivkumar
Mary E J
ME
Lott
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001921:Brain / Q000473:pathology*; D002908:Chronic Disease; D005260:Female; D006801:Humans; D056784:Leukoencephalopathies / Q000150:complications / Q000473:pathology*; D016014:Linear Models; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012171:Retinal Vessels / Q000473:pathology / Q000503:physiopathology*; D020521:Stroke / Q000150:complications / Q000473:pathology*; D017585:Ultrasonography, Doppler, Transcranial