19 February 2018 Why choroid vessels appear dark in clinical OCT images
Author Affiliations +
Proceedings Volume 10474, Ophthalmic Technologies XXVIII; 1047428 (2018) https://doi.org/10.1117/12.2291057
Event: SPIE BiOS, 2018, San Francisco, California, United States
With the onset of clinically available spectral domain (SD-OCT) and swept source (SS-OCT) systems, clinicians are now easily able to recognize sub retinal microstructure and vascularization in the choroidal and scleral regions. As the bloodrich choroid supplies nutrients to the upper retinal layers, the ability to monitor choroid function accurately is of vital importance for clinical assessment of retinal health. However, the physical appearance of the choroid blood vessels (darker under a healthy Retinal Pigmented Epithelium (RPE) compared to regions displaying an RPE atrophic lesion) has led to confusion within the OCT ophthalmic community. The differences in appearance between each region in the OCT image may be interpreted as different vascular patterns when the vascular networks are in fact very similar. To explain this circumstance, we simulate light scattering phenomena in the RPE and Choroid complexes using the finite difference time domain (FDTD) method. The simulation results are then used to describe and validate imaging features in a controlled multi-layered tissue phantom designed to replicate human RPE, choroid, and whole blood microstructure. Essentially, the results indicate that the strength of the OCT signal from choroidal vasculature is dependent on the health and function of the RPE, and may not necessarily directly reflect the health and function of the choroidal vasculature.
© (2018) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Mitchell A. Kirby, Mitchell A. Kirby, Chenxi Li, Chenxi Li, Woo June Choi, Woo June Choi, Giovanni Gregori, Giovanni Gregori, Philip Rosenfeld, Philip Rosenfeld, Ruikang Wang, Ruikang Wang, } "Why choroid vessels appear dark in clinical OCT images", Proc. SPIE 10474, Ophthalmic Technologies XXVIII, 1047428 (19 February 2018); doi: 10.1117/12.2291057; https://doi.org/10.1117/12.2291057

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