LV Prasad Eye Institute, Hyderabad, India.
Retina and Uveitis Department, GMR Varalakshmi Campus, LV Prasad Eye Institute, Visakhapatnam, India.
Invest Ophthalmol Vis Sci. 2019 Aug 1;60(10):3563-3569. doi: 10.1167/iovs.18-26381.
To obtain a choroidal vascularity index (CVI) map of macular area on an Early Treatment Diabetic Retinopathy Study (ETDRS) grid.
The study was a cross-sectional study involving 30 eyes of 30 healthy individuals. In brief, a shadow-compensated automated algorithm was used to segment and binarize the individual optical coherence tomography (OCT) B-scans. This was followed by three-dimensional reconstruction of these processed B-scans to obtain the overall thickness and vascularity maps. ETDRS grid was overlaid on both the extrapolated thickness and vascularity maps to obtain the corresponding sector-wise CVI. The main outcome measure was to evaluate the topographical variation of CVI in the macular area.
The mean age of the study participants was 44.33 ± 16.29 years (range, 18-70 years). CVI showed no significant difference in different rings, subfields, or quadrants of the ETDRS map. CVI had a negative correlation with age (r = -0.384, P = 0.03). There were no statistically significant differences between CVI of both eyes in either rings or the full ETDRS grid (P = 0.30) among normal subjects.
The variation in CVI does not follow similar patterns as seen in choroidal thickness (CT) in various locations. The novel choroidal vascularity mapping in the macular area may expand understanding on regional differences of choroidal vasculature in healthy eyes.
获取黄斑区 ETDRS 网格上的脉络膜血管指数（CVI）图。
这是一项横断面研究，共纳入 30 名健康个体的 30 只眼。简要来说，使用阴影补偿自动算法对每个 OCT B 扫描进行分割和二值化。然后对这些处理后的 B 扫描进行三维重建，以获得整体厚度和血管图。将 ETDRS 网格叠加在扩展的厚度和血管图上，以获得相应的扇形 CVI。主要观察指标是评估黄斑区 CVI 的地形变化。
研究参与者的平均年龄为 44.33±16.29 岁（范围，18-70 岁）。CVI 在 ETDRS 图的不同环、亚区或象限之间没有显著差异。CVI 与年龄呈负相关（r=-0.384，P=0.03）。在正常受试者中，双眼的 CVI 在环或整个 ETDRS 网格中均无统计学差异（P=0.30）。
CVI 的变化与不同部位脉络膜厚度（CT）的变化模式不同。黄斑区脉络膜新的血管成像可能有助于加深对健康眼中脉络膜血管区域性差异的理解。
