摘要： Objective: To evaluate the degree of microvascular impairment in diabetic retinopathy using multifractal and lacunarity analyses and to compare the diagnostic ability between traditional Euclidean measures (fovea avascular zone area and vessel density) and fractal geometric features. Methods: This retrospective cross-sectional study included a total of 143 eyes of 94 patients with different stages of diabetic retinopathy. The retinal microvasculature was imaged by projection removed optical coherence tomography angiography. We examined the degree of association between fractal metrics of the retinal microvasculature and diabetic retinopathy severity. The area under the receiver operating characteristic curve was used to estimate the diagnostic performance. Results: With increasing diabetic retinopathy severity, the multifractal spectrum shifted towards the left bottom and exhibited less left skewness and asymmetry. The vessel density, multifractal features and lacunarity measured from the deep capillary plexus were strongly associated with diabetic retinopathy severity. The multifractal feature D5 showed the highest diagnostic ability. The combination of multifractal features further improved the discriminating power. Conclusions: Multifractal and lacunarity analyses can be potentially valuable tools for assessment of microvascular impairments in diabetic retinopathy. Multifractal geometric parameters exhibit a better discriminatory performance than Euclidean measures, particularly for detection of the early stages of diabetic retinopathy.