Quantitative assessment of retinal attenuation and backscattering in OCT imaging using iterative layer-based analysis

Optical coherence tomography (OCT) generates cross-sectional images by measuring backscattered light from within tissue, with image contrast influenced by tissue optical properties, primarily optical scattering and illumination conditions. The optical attenuation coefficient (OAC), derived from the OCT signal, can decouple illumination effects and directly probe the scattering properties, offering potential functional contrast. However, the existing OAC quantification methods are prone to bias in multilayered structures, such as retinal tissue, primarily due to the inhomogeneity in backscattering fraction. In this study, we introduce a layer-based iterative method that improves OAC accuracy by accounting for layer-specific backscattering fractions. Our approach refines OAC calculations through an optimized depth-resolved framework, iteratively adjusting the residual light term for improved estimation. We validated the method's convergence and accuracy through both mathematical derivation and numerical simulations. Further, we evaluated its clinical applicability in healthy subjects. Comparative results demonstrated that our method enhances tissue characterization, highlighting its potential to advance retinal imaging and disease assessment.