Kim Alice Y, Chu Zhongdi, Shahidzadeh Anoush, Wang Ruikang K, Puliafito Carmen A, Kashani Amir H
Department of Ophthalmology USC Eye Institute, Keck School of Medicine of the University of Southern California, Los Angeles, California, United States.
Departments of Bioengineering and Ophthalmology, University of Washington, Seattle, Washington, United States.
Invest Ophthalmol Vis Sci. 2016 Jul 1;57(9):OCT362-70. doi: 10.1167/iovs.15-18904.
To quantify changes in retinal microvasculature in diabetic retinopathy (DR) by using spectral-domain optical coherence tomography angiography (SD-OCTA).
Retrospective, cross-sectional, observational study of healthy and diabetic adult subjects with and without DR. Retinal microvascular changes were assessed by using SD-OCTA images and an intensity-based optical microangiography algorithm. A semiautomated program was used to calculate indices of microvascular density and morphology in nonsegmented and segmented SD-OCTA images. Microvascular density was quantified by using skeleton density (SD) and vessel density (VD), while vessel morphology was quantified as fractal dimension (FD) and vessel diameter index (VDI). Statistical analyses were performed by using the Student's t-test or analysis of variance with post hoc Tukey honest significant difference tests for multiple comparisons.
Eighty-four eyes with DR and 14 healthy eyes were studied. Spearman's rank test demonstrated a negative correlation between DR severity and SD, VD, and FD, and a positive correlation with VDI (ρ = -0.767, -0.7166, -0.768, and +0.5051, respectively; P < 0.0001). All parameters showed high reproducibility between graders (ICC = 0.971, 0.962, 0.937, and 0.994 for SD, VD, FD, and VDI, respectively). Repeatability (κ) was greater than 0.99 for SD, VD, FD, and VDI.
Vascular changes in DR can be objectively and reliably characterized with SD, VD, FD, and VDI. In general, decreasing capillary density (SD and VD), branching complexity (FD), and increasing average vascular caliber (VDI) were associated with worsening DR. Changes in capillary density and morphology were significantly correlated with diabetic macular edema.
通过使用谱域光学相干断层扫描血管造影（SD-OCTA）来量化糖尿病视网膜病变（DR）中视网膜微血管的变化。
对患有和未患有DR的健康及糖尿病成年受试者进行回顾性、横断面观察性研究。使用SD-OCTA图像和基于强度的光学微血管造影算法评估视网膜微血管变化。使用半自动程序计算非分割和分割的SD-OCTA图像中的微血管密度和形态学指标。微血管密度通过骨架密度（SD）和血管密度（VD）进行量化，而血管形态通过分形维数（FD）和血管直径指数（VDI）进行量化。使用Student's t检验或方差分析以及事后Tukey诚实显著差异检验进行多重比较的统计分析。
研究了84只患有DR的眼睛和14只健康眼睛。Spearman秩检验显示DR严重程度与SD、VD和FD之间呈负相关，与VDI呈正相关（分别为ρ = -0.767、-0.7166、-0.768和 +0.5051；P < 0.0001）。所有参数在分级者之间均显示出高重现性（SD、VD、FD和VDI的组内相关系数分别为0.971、0.962、0.937和0.994）。SD、VD、FD和VDI的重复性（κ）大于0.99。
DR中的血管变化可以通过SD、VD、FD和VDI进行客观可靠的表征。一般来说，毛细血管密度（SD和VD）降低、分支复杂性（FD）降低以及平均血管口径（VDI）增加与DR恶化相关。毛细血管密度和形态的变化与糖尿病性黄斑水肿显著相关。
