Taylor Adele M, MacGillivray Thomas J, Henderson Ross D, Ilzina Lasma, Dhillon Baljean, Starr John M, Deary Ian J
Department of Psychology, University of Edinburgh, Edinburgh, United Kingdom.
Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom; Clinical Research Imaging Centre, University of Edinburgh, Edinburgh, United Kingdom; Clinical Research Facility, University of Edinburgh, Edinburgh, United Kingdom.
PLoS One. 2015 Mar 27;10(3):e0121119. doi: 10.1371/journal.pone.0121119. eCollection 2015.
Cerebral microvascular disease is associated with dementia. Differences in the topography of the retinal vascular network may be a marker for cerebrovascular disease. The association between cerebral microvascular state and non-pathological cognitive ageing is less clear, particularly because studies are rarely able to adjust for pre-morbid cognitive ability level. We measured retinal vascular fractal dimension (Df) as a potential marker of cerebral microvascular disease. We examined the extent to which it contributes to differences in non-pathological cognitive ability in old age, after adjusting for childhood mental ability.
Participants from the Lothian Birth Cohort 1936 Study (LBC1936) had cognitive ability assessments and retinal photographs taken of both eyes aged around 73 years (n = 648). IQ scores were available from childhood. Retinal vascular Df was calculated with monofractal and multifractal analysis, performed on custom-written software. Multiple regression models were applied to determine associations between retinal vascular Df and general cognitive ability (g), processing speed, and memory.
Only three out of 24 comparisons (two eyes × four Df parameters × three cognitive measures) were found to be significant. This is little more than would be expected by chance. No single association was verified by an equivalent association in the contralateral eye.
The results show little evidence that fractal measures of retinal vascular differences are associated with non-pathological cognitive ageing.
脑微血管疾病与痴呆症相关。视网膜血管网络拓扑结构的差异可能是脑血管疾病的一个标志。脑微血管状态与非病理性认知老化之间的关联尚不清楚，尤其是因为研究很少能够对病前认知能力水平进行校正。我们测量了视网膜血管分形维数（Df），将其作为脑微血管疾病的一个潜在标志。在对儿童期智力进行校正后，我们研究了它在多大程度上导致老年非病理性认知能力的差异。
来自1936年洛锡安出生队列研究（LBC1936）的参与者在73岁左右时接受了认知能力评估并拍摄了双眼的视网膜照片（n = 648）。可获得其儿童期的智商分数。使用自定义编写的软件通过单分形和多分形分析计算视网膜血管Df。应用多元回归模型来确定视网膜血管Df与一般认知能力（g）、处理速度和记忆力之间的关联。
在24项比较（双眼×4个Df参数×3项认知指标）中，仅发现3项具有显著性。这略高于偶然预期的结果。对侧眼的等效关联未验证任何单一关联。
结果几乎没有表明视网膜血管差异的分形测量与非病理性认知老化相关的证据。
