Fundus Spectral Imaging: from Optical Systems to Clinical Applications

Fundus spectral imaging (FSI) integrates spatial and spectral information, providing a noninvasive alternative for structural and functional fundus examinations. It has demonstrated significant potential in detecting diseases such as choroidal tumors. However, a systematic review comprehensively summarizing the progress of FSI from optical system construction to clinical applications remains lacking, hindering its further development and clinical adoption. This review first examines the optical principles underlying FSI, including the optical model of the human eye and the optical components of fundus camera systems. Subsequently, it discusses technical strategies for implementing FSI, including various hardware upgrades based on existing fundus camera systems. Furthermore, this paper systematically evaluates various spectral imaging techniques applicable to FSI, classifying them into targeted-point spectral imaging (TPSI) and wide-field spectral imaging (WFSI), with the latter further divided into scanning, staring, transformed, and snapshot modes. The performance, advantages, and limitations of these methods are analyzed in detail. Additionally, the clinical applications of FSI are explored through specific case studies, highlighting its role in both structural and functional fundus assessments. Finally, this review summarizes the challenges facing FSI and explores future directions. This review aims to provide valuable insights for researchers and clinicians in the fields of optical imaging and ophthalmology.