Purpose:To test the feasibility of using deep learning for optical coherence tomography angiography (OCTA) detection of diabetic retinopathy (DR).
Methods:A deep learning convolutional neural network (CNN) architecture VGG16 was employed for this study. A transfer learning process was implemented to re-train the CNN for robust OCTA classification.In order to demonstrate the feasibility of using this method for artificial intelligence (AI) screening of DR in clinical environments, the re-trained CNN was incorporated into a custom developed GUI platform which can be readily operated by ophthalmic personnel.
Results:With last nine layers re-trained, CNN architecture achieved the best performance for automated OCTA classification. The overall accuracy of the re-trained classifier for differentiating healthy, NoDR, and NPDR was 87.27%, with 83.76% sensitivity and 90.82% specificity. The AUC metrics for binary classification of healthy, NoDR and DR were 0.97, 0.98 and 0.97, respectively. The GUI platform enabled easy validation of the method for AI screening of DR in a clinical environment.
Conclusion:With a transfer leaning process to adopt the early layers for simple feature analysis and to retrain the upper layers for fine feature analysis, the CNN architecture VGG16 can be used for robust OCTA classification of healthy, NoDR, and NPDR eyes. Translational Relevance: OCTA can capture microvascular changes in early DR. A transfer learning process enables robust implementation of convolutional neural network (CNN) for automated OCTA classification of DR. detection and adequate treatment, more than 95% of DR related vision loss can be preventable [2]. Retinal vascular abnormalities, such as microaneurysms, hard exudates, retinal edema, venous beading, intraretinal microvascular anomalies and retinal hemorrhages are common DR findings [3]. Therefore, imaging examination of retinal vasculature is important for DR diagnosis and treatment evaluation. Traditional fundus photography provides limited sensitivity to reveal subtle abnormality correlated with early DR [4][5][6][7]. Fluorescein angiography (FA) can be used to improve imaging sensitivity of retinal vascular distortions in DR [8,9], but FA requires intravenous dye injections which may produce side effects and requires following monitoring and management carefully. Optical coherence tomography angiography (OCTA) provides a noninvasive method for better visualization of retinal vasculatures [10]. OCTA allows visualization of multiple retinal layers with high resolution, and thus it is more sensitive than FA in detecting subtle vascular distortions correlated with early eye conditions [11,12].Recent development of quantitative OCTA opens a unique opportunity to enable computer-aided disease detection and AI classification of eye conditions. Quantitative OCTA analysis has been explored for objective assessment of DR [13][14][15][16], age-related macular degeneration (AMD) [17,18], vein occlusion (VO) [19][20][21][22], SCR [23][24][25], etc. Supervised machine learning h...