Purpose: To determine the ability of fractal dimension to detect early changes in the retinal microvascular network imaged by optical coherence tomography angiography (OCT-A) in type 2 diabetic patients. Methods: Sixty-seven patients with type 2 diabetic mellitus (DM) (48 with no diabetic retinopathy [DR], 19 with minimal DR) and 40 control subjects. Macular OCT-A images of the superficial and deep retinal capillary layers in a 2.5-mm diameter concentric annular zone (excluding the foveal avascular zone) were subdivided into six annular rings and four quadrants. A custom automated algorithm was developed to quantify the complexity and density of the two retinal capillary layers by fractal analysis. Results: Compared to controls, the fractal dimensional parameter (Dbox) of the two retinal capillary layers in most regions was significantly lower in diabetic patients with minimal DR (P < 0.05). The Dbox of the diabetic patients with no DR was also decreased in most regions of the deep retinal capillary layer (P < 0.05), but not in the superficial retinal capillary layer (P > 0.05). Based on the receiver operating characteristic curve analysis, the Dbox values for the deep retinal capillary layer had the highest index to discriminate diabetic patients with and without minimal DR from controls. Conclusions: Fractal dimension based on OCT-A has the potential to quantitatively characterize retinal microvascular changes in the early stage of DM. Changes in the fractal dimension in the deep retinal capillary layer could be an early indicator of microvasculature changes associated with retinopathy in type 2 diabetic patients.
Purpose: To determine the ability of fractal dimension to detect early changes in the retinal microvascular network imaged by optical coherence tomography angiography (OCT-A) in type 2 diabeticpatients. Methods: Sixty-seven patients with type 2 diabetic mellitus (DM) (48 with no diabetic retinopathy [DR], 19 with minimal DR) and 40 control subjects. Macular OCT-A images of the superficial and deep retinal capillary layers in a 2.5-mm diameter concentric annular zone (excluding the foveal avascular zone) were subdivided into six annular rings and four quadrants. A custom automated algorithm was developed to quantify the complexity and density of the two retinal capillary layers by fractal analysis. Results: Compared to controls, the fractal dimensional parameter (Dbox) of the two retinal capillary layers in most regions was significantly lower in diabeticpatients with minimal DR (P < 0.05). The Dbox of the diabeticpatients with no DR was also decreased in most regions of the deep retinal capillary layer (P < 0.05), but not in the superficial retinal capillary layer (P > 0.05). Based on the receiver operating characteristic curve analysis, the Dbox values for the deep retinal capillary layer had the highest index to discriminate diabeticpatients with and without minimal DR from controls. Conclusions: Fractal dimension based on OCT-A has the potential to quantitatively characterize retinal microvascular changes in the early stage of DM. Changes in the fractal dimension in the deep retinal capillary layer could be an early indicator of microvasculature changes associated with retinopathy in type 2 diabeticpatients.
Authors: Richard B Rosen; Jorge S Andrade Romo; Brian D Krawitz; Shelley Mo; Amani A Fawzi; Rachel E Linderman; Joseph Carroll; Alexander Pinhas; Toco Y P Chui Journal: Am J Ophthalmol Date: 2019-01-26 Impact factor: 5.258
Authors: Yifan Lu; Jay C Wang; Ying Cui; Ying Zhu; Rebecca Zeng; Edward S Lu; Raviv Katz; Deeba Husain; Demetrios G Vavvas; Leo A Kim; Joan W Miller; John B Miller Journal: Graefes Arch Clin Exp Ophthalmol Date: 2020-09-25 Impact factor: 3.117
Authors: Jing Yan Yang; Qian Wang; Yan Ni Yan; Wen Jia Zhou; Ya Xing Wang; Shou Ling Wu; Ming Xia Yuan; Wen Bin Wei; Jost B Jonas Journal: Graefes Arch Clin Exp Ophthalmol Date: 2020-01-02 Impact factor: 3.117