OCT-guided angle-resolved low-coherence interferometry for microstructural analysis of the human retina.

Angle-resolved low-coherence interferometry (a/LCI) is an optical technique for extracting depth-resolved angular scattering profiles from biological tissues. Analysis of these angular scattering profiles can be used to compute the two-point spatial correlation function, which enables quantification of tissue structural heterogeneity at sub-cellular length scales. Building on previous work that combined a/LCI and optical coherence tomography (OCT) to detect biomarkers of Alzheimer's disease (AD) in ex vivo murine models, this study seeks to translate the platform for noninvasive scattering analysis of the human retina. The resulting system combines OCT image guidance, enabled by our high-performance, low-cost OCT platform, with parafoveal angular scattering measurements in each retinal quadrant, using 2D a/LCI. Measurements from 11 healthy participants were used to characterize retinal microstructure at length scales ranging from 4.8 μm to 9.5 μm. Our results revealed consistent variations in the structural correlations across retinal layers and quadrants, establishing baseline healthy measurements for future studies. This dual-modality approach offers a promising framework for improving diagnostic sensitivity in a variety of retinal and neurological disorders.