Pamulapati Pravallika, Das Manmath K, Mohanty Gayatree
Ophthalmology, Kalinga Institute of Medical Sciences, Bhubaneswar, IND.
Cureus. 2024 Oct 31;16(10):e72747. doi: 10.7759/cureus.72747. eCollection 2024 Oct.
Objective The present study aimed to investigate the variations in retinal microvascular parameters among diabetic patients without diabetic retinopathy (No DR), those with nonproliferative diabetic retinopathy (NPDR), and healthy controls using spectral domain optical coherence tomography angiography (SD-OCTA). Methods An observational cross-sectional case-control study was conducted involving 68 eyes classified into three groups: 32 eyes with No DR, 16 eyes with NPDR, and 20 controls. The study assessed parameters such as perfused capillary vessel density, foveal avascular zone (FAZ) area, mean vessel diameter, number of capillary dropouts, and flow void areas. OCTA images were obtained using the SD-OCT system (Spectralis HRA, Heidelberg Engineering, Germany) and analyzed with custom MATLAB software. Statistical analysis was performed using SPSS Statistics (IBM Corp., Armonk, NY), with significance set at p<0.05. Results Significant differences were observed across the groups for perfused capillary density, FAZ area, number of capillary dropouts, and number of flow void areas. Specifically, NPDR patients exhibited a significantly lower perfused capillary density (36.50%) and No DR patients demonstrated a considerably higher perfused capillary density (43.98%) when compared with controls (42.71%; p<0.001). The FAZ area was significantly larger in NPDR patients (0.5981 mm²) compared to the No DR (0.3581 mm²) and controls (0.3550 mm; p<0.001). The number of capillary dropouts and flow void areas were significantly higher in NPDR patients but were also detected in the No DR group (p<0.001). No significant differences were found in mean vessel diameter among the groups (p=0.061). Conclusions The study confirms that NPDR is associated with distinct changes in retinal microvascular parameters compared to both No DR and control groups. These changes include reduced perfused capillary density, increased FAZ area, and elevated numbers of capillary dropouts and flow void areas. It also confirms that No DR can be associated with increased capillary vessel density as well as with capillary dropouts and void areas. OCTA proves to be a valuable instrument for evaluating retinal microvascular changes and could aid in the early detection and treatment of diabetic retinopathy (DR).
目的 本研究旨在利用光谱域光学相干断层扫描血管造影（SD-OCTA）研究无糖尿病视网膜病变（无DR）的糖尿病患者、非增殖性糖尿病视网膜病变（NPDR）患者和健康对照者视网膜微血管参数的变化。方法 进行一项观察性横断面病例对照研究，纳入68只眼睛，分为三组：32只无DR眼睛、16只NPDR眼睛和20只对照眼睛。该研究评估了灌注毛细血管密度、黄斑无血管区（FAZ）面积、平均血管直径、毛细血管缺失数量和血流信号缺失区域等参数。使用SD-OCT系统（德国海德堡工程公司的Spectralis HRA）获取OCTA图像，并使用定制的MATLAB软件进行分析。使用SPSS Statistics（IBM公司，纽约州阿蒙克）进行统计分析，显著性设定为p<0.05。结果 在灌注毛细血管密度、FAZ面积、毛细血管缺失数量和血流信号缺失区域数量方面，各组之间观察到显著差异。具体而言，与对照组（42.71%；p<0.001）相比，NPDR患者的灌注毛细血管密度显著降低（36.50%），无DR患者的灌注毛细血管密度显著更高（43.98%）。NPDR患者的FAZ面积（0.5981 mm²）明显大于无DR患者（0.3581 mm²）和对照组（0.3550 mm；p<0.001）。NPDR患者的毛细血管缺失数量和血流信号缺失区域数量显著更高，但在无DR组中也有发现（p<0.001）。各组之间的平均血管直径没有显著差异（p=0.061）。结论 该研究证实，与无DR组和对照组相比，NPDR与视网膜微血管参数的明显变化有关。这些变化包括灌注毛细血管密度降低、FAZ面积增加以及毛细血管缺失数量和血流信号缺失区域数量增加。研究还证实，无DR可能与毛细血管密度增加以及毛细血管缺失和血流信号缺失区域有关。OCTA被证明是评估视网膜微血管变化的有价值工具，有助于糖尿病视网膜病变（DR）的早期检测和治疗。
