Imaging melanin-associated organelles in the retinal pigment epithelium via visible light OCT redshift.

The retinal pigment epithelium (RPE) performs a number of functions essential for retinal health. RPE dysregulation and degeneration can occur in diseases. Methods to image the human RPE directly are limited, as it is only about 10 µm thick and situated between the photoreceptor outer segments and Bruch's membrane (BM). Here we propose a visible light optical coherence tomography (OCT) technique to image the spectral redshift as light traverses the apical to basal RPE. Results in mice and human subjects support that the redshift occurs due to melanosomes and melanolipofuscin in the apical and middle RPE cell body.