Medical Research Foundation, Sankara Nethralaya, Chennai, Tamil Nadu, India.
National Healthcare Group Eye Institute, Tan Tock Seng Hospital, Singapore.
PLoS One. 2018 Dec 11;13(12):e0207435. doi: 10.1371/journal.pone.0207435. eCollection 2018.
To evaluate structural changes in the choroid among patients with diabetic macular edema (DME), with varying grades of diabetic retinopathy (DR), using enhance depth imaging spectral domain optical coherence tomography (EDI SD-OCT) scans.
A cross-sectional study was conducted on 82 eyes with DR and DME and 86 healthy control eyes. Eyes with DME were classified according to the severity of DR as per the international DR severity scale. Sub foveal choroidal thickness (SFCT)was obtained using EDI SD-OCT scans. These scans were binarized into luminal and stromal areas, to derive the choroidal vascularity index (CVI). CVI and SFCT were analyzed between the study and control group using paired-T test. Tukey's test was used to correlate the differences in CVI and SFCT between different grades of DR. Further analysis was done to look for the effect of DR severity and type of DME on CVI as well as SFCT using correlation coefficient and linear regression analysis.
SFCT was significantly increased in eyes with DME as compared to the controls (334.47±51.81μm vs 284.53±56.45μm, p<0.001), and showed an ascending trend with worsening of DR, though this difference was not statistically significant [mild non-proliferative diabetic retinopathy (NPDR) = 304.33±40.39μm, moderate NPDR = 327.81±47.39μm, severe NPDR = 357.72±62.65μm, proliferative DR (PDR) = 334.59±47.4μm, p-0.09]. CVI was significantly decreased in DME with DR eyes as compared to controls (63.89±1.89 vs 67.51±2.86, p<0.001). CVI was also significantly decreased with worsening DR (mild NPDR = 66.38±0.3, moderate NPDR = 65.28±0.37, severe NPDR = 63.50±0.47, PDR = 61.27±0.9, p<0.001).
SFCT and CVI are dynamic parameters that are affected by DME. Unlike CVI, SFCT is also affected by ocular and systemic factors like edema and hypertension. CVI may be a more accurate surrogate marker for DME and DR and can potentially be used to monitor the progression of DR.
使用增强深度成像谱域光学相干断层扫描（EDI SD-OCT）评估糖尿病性黄斑水肿（DME）患者脉络膜结构变化，这些患者的糖尿病视网膜病变（DR）程度不同。
对 82 只 DR 和 DME 眼和 86 只健康对照眼进行横断面研究。根据国际 DR 严重程度量表，将 DME 眼根据 DR 的严重程度进行分类。使用 EDI SD-OCT 扫描获得中心凹下脉络膜厚度（SFCT）。这些扫描被二值化为管腔和基质区域，以得出脉络膜血管指数（CVI）。使用配对 t 检验比较研究组和对照组之间的 CVI 和 SFCT。使用 Tukey 检验比较不同 DR 分级之间的 CVI 和 SFCT 差异。进一步分析使用相关系数和线性回归分析来研究 DR 严重程度和 DME 类型对 CVI 和 SFCT 的影响。
与对照组相比，DME 眼的 SFCT 明显增加（334.47±51.81μm 比 284.53±56.45μm，p<0.001），并且随着 DR 的恶化呈上升趋势，尽管这一差异无统计学意义[轻度非增殖性糖尿病视网膜病变（NPDR）=304.33±40.39μm，中度 NPDR=327.81±47.39μm，重度 NPDR=357.72±62.65μm，增殖性 DR（PDR）=334.59±47.4μm，p=0.09]。与对照组相比，DR 合并 DME 眼的 CVI 明显降低（63.89±1.89 比 67.51±2.86，p<0.001）。CVI 也随着 DR 的恶化而显著降低（轻度 NPDR=66.38±0.3，中度 NPDR=65.28±0.37，重度 NPDR=63.50±0.47，PDR=61.27±0.9，p<0.001）。
SFCT 和 CVI 是受 DME 影响的动态参数。与 CVI 不同，SFCT 还受到眼部和全身因素（如水肿和高血压）的影响。CVI 可能是 DME 和 DR 的更准确替代标志物，并且可能可用于监测 DR 的进展。
