Frydkjaer-Olsen Ulrik, Soegaard Hansen Rasmus, Pedersen Knud, Peto Tunde, Grauslund Jakob
Department of Ophthalmology, Odense University Hospital, Odense, Denmark 2Institute of Clinical Research, University of Southern Denmark, Odense, Denmark.
Institute of Clinical Research, University of Southern Denmark, Odense, Denmark 3The NIHR Biomedical Research Centre, Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, United Kingdom.
Invest Ophthalmol Vis Sci. 2015 Nov;56(12):7438-43. doi: 10.1167/iovs.15-17449.
To investigate the correlation between the retinal vascular fractal dimension (Fd) and neurodegenerative changes in patients with no or mild diabetic retinopathy (DR).
In this cross-sectional study we examined 103 patients with type 2 diabetes mellitus (T2DM) with no or mild DR. In a randomly selected eye of each patient, Fd was calculated using SIVA-Fractal, a specialized semiautomatic software. Retinal neurodegeneration was evaluated by Topcon 3D OCT-2000 spectral-domain optical coherence tomography (OCT) and by a RETI-scan multifocal ERG (mf-ERG) system in rings one to six. Level of DR was determined by a single trained grader in seven-field fundus photos according to the Early Treatment Diabetic Retinopathy Study (ETDRS) scale.
Mean age and duration of T2DM were 62.3 and 11.6 years, respectively; 46.6% were men. Mean Fd was 1.413 (range, 1.278-1.509) and ETDRS levels were 10 (42.7%), 20 (35.0%), and 35 (22.3%), respectively. Fd correlated inversely with mf-ERG implicit time of ring one (r = -0.25, P = 0.01) and present diabetic neuropathy (P = 0.02), and positively with OCT ganglion cell layer (GCL) thickness (r = 0.20, P = 0.04). In a multivariable linear regression model, Fd was associated with mf-ERG implicit time of ring one (coefficient -0.0021/ms, P = 0.040) and the presence of diabetic neuropathy (coefficient -0.0209 for neuropathy present versus absent, P = 0.041).
In patients with T2DM and no or minimal DR, independent correlations were found between early vascular and neurogenic changes. Thus, retinal vascular fractal analysis might be considered as a tool to identify patients with early neurodegenerative retinal changes.
研究无糖尿病视网膜病变（DR）或轻度DR患者的视网膜血管分形维数（Fd）与神经退行性变之间的相关性。
在这项横断面研究中，我们检查了103例无DR或轻度DR的2型糖尿病（T2DM）患者。在每位患者随机选择的一只眼中，使用专门的半自动软件SIVA - Fractal计算Fd。通过Topcon 3D OCT - 2000光谱域光学相干断层扫描（OCT）和RETI - scan多焦视网膜电图（mf - ERG）系统在1至6环评估视网膜神经退行性变。根据早期糖尿病视网膜病变研究（ETDRS）量表，由一名经过培训的分级人员在七视野眼底照片中确定DR水平。
T2DM患者的平均年龄和病程分别为62.3岁和11.6年；46.6%为男性。平均Fd为1.413（范围为1.278 - 1.509），ETDRS水平分别为10（42.7%）、20（35.0%）和35（22.3%）。Fd与1环的mf - ERG潜伏时间呈负相关（r = -0.25，P = 0.01）以及与现患糖尿病神经病变呈负相关（P = 0.02），与OCT神经节细胞层（GCL）厚度呈正相关（r = 0.20，P = 0.04）。在多变量线性回归模型中，Fd与1环的mf - ERG潜伏时间相关（系数为-0.0021/ms，P = 0.040）以及与糖尿病神经病变的存在相关（神经病变存在与不存在的系数为-0.0209，P = 0.041）。
在无DR或轻度DR的T2DM患者中，发现早期血管和神经源性改变之间存在独立相关性。因此，视网膜血管分形分析可被视为识别早期视网膜神经退行性变患者的一种工具。
