To investigate the relationship between retinal microvascular abnormalities, brain imaging abnormalities and cognitive dysfunction, in the context of ageing and cardiovascular risk factors.
A literature search was carried out in MedLine for studies published between 1990 and 2012 on the association between retinal microvascular abnormalities, vascular abnormalities and atrophy on brain scans, cognitive function and dementia.
Thirty-two studies were included in total. In cross-sectional studies, retinal microvascular abnormalities were associated with atrophy and vascular lesions on brain scans (odds ratios (ORs) 0.9 to 3.0), reduced cognitive function or dementia (ORs 1.1 to 5.5). Longitudinal studies showed no clear associations with cognitive function or dementia. However, there were indications that retinal microvascular damage was associated with progression of brain scan abnormalities (ORs 0.8 to 3.2).
Retinal microvascular abnormalities are associated with vascular lesions and atrophy on brain scans, and with cognitive impairment and dementia, especially for severe retinal microvascular damage. This emphasizes the aetiological importance of vascular disease in the onset of cognitive dysfunction and dementia. Assessment of the retina does not appear to be an effective screening method to identify individuals with an increased risk of cognitive impairment or dementia.
Conflict of interest and financial support: ICMJE forms provided by the authors are available online along with the full text of this article.