The eye as a window to systemic health: A survey of retinal imaging from classical techniques to oculomics

The unique vascularized anatomy of the human eye, encased in the retina, provides an opportunity to act as a window for human health.The retinal structure assists in assessing the early detection, monitoring of disease progression and intervention for both ocular and non-ocular diseases.The advancement in imaging technology leveraging Artificial Intelligence has seized this opportunity to bridge the gap between the eye and human health.This approach facilitates the unveiling of systemic health insights from the ocular system and the identification of noninvasive surrogate markers for timely intervention and detection.The new frontiers of oculomics in ophthalmology cover both ocular and systemic diseases, and are getting more attention to explore them.In this survey paper, we explore the evolution of retinal imaging techniques, the dire need for the integration of AI-driven analysis, and the shift of retinal imaging from classical techniques to oculomics.We also discuss some hurdles that may be faced in the progression of oculomics, highlighting the research gaps and future directions.