Department of Clinical Pharmacology, Medical University of Vienna, Austria.
Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Austria.
Invest Ophthalmol Vis Sci. 2019 Jul 1;60(8):3162-3169. doi: 10.1167/iovs.18-26234.
To investigate the age-dependence of total retinal blood flow and total retinal oxygen extraction in healthy subjects and determine their possible correlations with structural optical coherence tomography (OCT) parameters.
This observational cross-sectional study consisted of 68 healthy subjects (mean ± SD age, 45.6 ± 16.3 years; 47% female). Total retinal oxygen extraction was calculated based on measurement of total retinal blood flow using bi-directional Doppler OCT and measurement of oxygen saturation using spectroscopic reflectometry. Retinal nerve fiber layer thickness was measured using OCT, and the total number of retinal ganglion cells was estimated based on a previous published model. Correlation of these parameters with age was studied and the association between structural OCT parameters and hemodynamic vascular parameters was calculated.
Both structural and vascular parameters showed a significant decline with increasing age. The correlation coefficients were between r = -0.25 and r = -0.41. Furthermore, structural and vascular parameters were significantly correlated with each other. The strongest association was found between the level of total retinal oxygen extraction and the number of retinal ganglion cells (r = 0.75, P < 0.001).
We showed that there was an age-related decline of retinal oxygen extraction. Levels of retinal oxygen extraction are correlated to retinal nerve fiber layer thickness and number of retinal ganglion cells. Our data partially explain the wide inter-individual variability in retinal blood flow values in healthy subjects. Longitudinal studies are required to study the time course of vascular and neuronal loss in humans.
研究健康受试者视网膜总血流量和总视网膜氧提取率随年龄的变化，并确定其与结构光学相干断层扫描（OCT）参数的可能相关性。
本观察性横断面研究纳入了 68 名健康受试者（平均年龄 ± 标准差，45.6 ± 16.3 岁；47%为女性）。基于双向多普勒 OCT 测量的视网膜总血流量和光谱反射率测量的氧饱和度，计算总视网膜氧提取率。使用 OCT 测量视网膜神经纤维层厚度，并根据先前发表的模型估计视网膜神经节细胞的总数。研究这些参数与年龄的相关性，并计算结构 OCT 参数与血流动力学血管参数之间的关联。
结构和血管参数均随年龄增长呈显著下降趋势。相关系数在 r = -0.25 至 r = -0.41 之间。此外，结构和血管参数之间存在显著相关性。总视网膜氧提取率与视网膜神经节细胞数量之间的相关性最强（r = 0.75，P < 0.001）。
我们表明，视网膜氧提取随年龄增长而下降。视网膜氧提取水平与视网膜神经纤维层厚度和视网膜神经节细胞数量相关。我们的数据部分解释了健康受试者视网膜血流量值个体间差异较大的原因。需要进行纵向研究以研究人类血管和神经元丢失的时间进程。
