High dynamic range choroidal imaging with transcranial illumination

This study presents the development of a nonmydriatic, contrast agent-free fundus camera using transcranial near-infrared (NIR) illumination for enhanced choroidal imaging. The proposed system addresses the limitations of traditional techniques like indocyanine green angiography (ICGA), which depends on contrast agents. It captures a wide snapshot field of view (FOV) of 185° eye angle (130° visual angle) without the need for pharmacological dilation. High dynamic range (HDR) imaging corrects illumination non-uniformity, ensuring consistent contrast and improved choroidal visualization. Testing on healthy individuals and patients with choroidal conditions demonstrated performance comparable to ICGA while providing a more accessible and affordable alternative. This HDR choroidal imager holds significant promise for advancing choroidal disorder screening and management, especially in underserved areas.