Deep Learning in Optical Coherence Tomography Angiography: Current Progress, Challenges, and Future Directions

Optical coherence tomography angiography (OCT-A) provides depth-resolved visualization of the retinal microvasculature without intravenous dye injection. It facilitates investigations of various retinal vascular diseases and glaucoma by assessment of qualitative and quantitative microvascular changes in the different retinal layers and radial peripapillary layer non-invasively, individually, and efficiently. Deep learning (DL), a subset of artificial intelligence (AI) based on deep neural networks, has been applied in OCT-A image analysis in recent years and achieved good performance for different tasks, such as image quality control, segmentation, and classification. DL technologies have further facilitated the potential implementation of OCT-A in eye clinics in an automated and efficient manner and enhanced its clinical values for detecting and evaluating various vascular retinopathies. Nevertheless, the deployment of this combination in real-world clinics is still in the proof-of-concept stage due to several limitations, such as small training sample size, lack of standardized data preprocessing, insufficient testing in external datasets, and absence of standardized results interpretation. In this review, we introduce the existing applications of DL in OCT-A, summarize the potential challenges of the clinical deployment, and discuss future research directions.

Automated summary

Optical coherence tomography angiography (OCT-A) provides non-invasive visualization of retinal microvasculature, and deep learning (DL) has been applied in OCT-A image analysis to enhance its clinical values. However, the deployment of this combination in real-world clinics is still in the proof-of-concept stage due to limitations in training sample size, data preprocessing, external dataset testing, and results interpretation standardization. In this review, we introduce the applications of DL in OCT-A, summarize the challenges of clinical deployment, and discuss future research directions.