Department of Ophthalmology, University Vita-Salute, IRCCS Ospedale San Raffaele, Milan, Italy.
Eye Clinic, Department of Neurological, Biomedical and Movement Sciences, University of Verona, Verona, Italy.
Br J Ophthalmol. 2019 Sep;103(9):1320-1326. doi: 10.1136/bjophthalmol-2018-313004. Epub 2018 Oct 25.
To analyse quantitative optical coherence tomography angiography (OCTA) parameters of choriocapillaris (CC) at the foveal, perifoveal and parafoveal regions in healthy subjects of different age.
In this observational cross-sectional study, consecutive healthy subjects underwent swept source OCTA (PLEX Elite 9000, Carl Zeiss Meditec, USA). 3×3 mm and 6×6 mm scans centred on the fovea were acquired analysed and postprocessed with thresholding and binarisation processes. The main outcome measures included CC quantitative OCTA features (perfusion density (PD), vessel length density (VLD) and vessel diameter index (VDI)) at the foveal, perifoveal and parafoveal regions, and their relationship with age.
Seventy-two eyes (72 patients, mean age 47.4±19.2 years, mean axial length 24.0±0.7 mm) were included. The mean PD was statistically lower in the foveal region compared with the parafoveal region in 3×3 mm scans (p=0.009). In subjects aged 70-80, PD of the foveal region was significantly reduced compared with the perifoveal region in 6×6 mm scans (p=0.008). A strong negative correlation was found between PD and ageing in the foveal, parafoveal and perifoveal regions (p<0.001 in all analyses). Furthermore, PD in the nasal-perifoveal region was significantly lower than the temporal-perifoveal region (p=0.005). No significant correlation was found between VLD and age in all regions, whereas VDI was strictly correlated with age (p<0.001).
We reported in vivo a strong negative correlation between PD and ageing in the CC of healthy subjects. This reduction seems related to a reduced diameter, and not to a reduced number, of capillaries. The age-related changes were higher in the central area compared with the perifoveal area.
分析不同年龄健康受试者黄斑、旁中心和中心凹外 3mm 处脉络膜毛细血管（CC）的定量光相干断层扫描血管造影（OCTA）参数。
本研究为观察性横断面研究，连续纳入行谱域 OCTA（PLEX Elite 9000，卡尔蔡司医疗技术公司，美国）检查的健康受试者。采集并分析以黄斑为中心的 3×3mm 和 6×6mm 扫描图像，并进行阈值和二值化处理。主要观察指标包括黄斑、旁中心和中心凹外 3mm 处 CC 的 OCTA 定量特征（灌注密度（PD）、血管长度密度（VLD）和血管直径指数（VDI））及其与年龄的关系。
共纳入 72 只眼（72 例患者，平均年龄 47.4±19.2 岁，平均眼轴长度 24.0±0.7mm）。3×3mm 扫描时，黄斑区的 PD 明显低于旁中心区（p=0.009）。在 70-80 岁的受试者中，6×6mm 扫描时，黄斑区的 PD 明显低于旁中心区（p=0.008）。在黄斑、旁中心和中心凹外 3mm 处，PD 与年龄呈强负相关（所有分析 p<0.001）。此外，鼻侧旁中心区的 PD 明显低于颞侧旁中心区（p=0.005）。在所有区域，VLD 与年龄均无显著相关性，而 VDI 与年龄呈严格正相关（p<0.001）。
本研究在健康受试者的脉络膜毛细血管中发现 PD 与年龄呈强负相关，这种降低似乎与毛细血管直径减小有关，而与毛细血管数量减少无关。与旁中心区相比，中心区的年龄相关性变化更高。
