TY - JOUR
T1 - Directional optical coherence tomography reveals melanin concentration-dependent scattering properties of retinal pigment epithelium
AU - Meleppat, Ratheesh K.
AU - Zhang, Pengfei
AU - Ju, Myeong Jin
AU - Manna, Suman K.
AU - Jian, Yifan
AU - Pugh, Edward N.
AU - Zawadzki, Robert J.
N1 - Funding Information:
Authors would like to acknowledge their funding sources: NSF I/UCRC CBSS Grant, NIH Grant Nos. EY026556 and EY012576 (NEI Core Grant), and Barr Retina Research Foundation gift to UC Davis Department of Ophthalmology. They thank Professor Ravi S. Jonnal (UC Davis Vision Science and Advanced Retinal Imaging Laboratory) and Marinko V. Sarunic (Simon Fraser University, Canada) for their fruitful discussions and support.
Publisher Copyright:
© The Authors.
PY - 2019/6/30
Y1 - 2019/6/30
N2 - Optical coherence tomography (OCT) is a powerful tool in ophthalmology that provides in vivo morphology of the retinal layers and their light scattering properties. The directional (angular) reflectivity of the retinal layers was investigated with focus on the scattering from retinal pigment epithelium (RPE). The directional scattering of the RPE was studied in three mice strains with three distinct melanin concentrations: albino (BALB/c), agouti (129S1/SvlmJ), and strongly pigmented (C57BL/6J). The backscattering signal strength was measured with a directional OCT system in which the pupil entry position of the narrow OCT beam can be varied across the dilated pupil of the eyes of the mice. The directional reflectivity of other retinal melanin-free layers, including the internal and external limiting membranes, and Bruch's membrane (albinos) were also measured and compared between the strains. The intensity of light backscattered from these layers was found highly sensitive to the angle of illumination, whereas the inner/outer segment (IS/OS) junctions showed a reduced sensitivity. The reflections from the RPE are largely insensitive in highly pigmented mice. The differences in directional scattering between strains shows that directionality decreases with an increase in melanin concentrations in RPE, suggesting increasing contribution of Mie scattering by melanosomes.
AB - Optical coherence tomography (OCT) is a powerful tool in ophthalmology that provides in vivo morphology of the retinal layers and their light scattering properties. The directional (angular) reflectivity of the retinal layers was investigated with focus on the scattering from retinal pigment epithelium (RPE). The directional scattering of the RPE was studied in three mice strains with three distinct melanin concentrations: albino (BALB/c), agouti (129S1/SvlmJ), and strongly pigmented (C57BL/6J). The backscattering signal strength was measured with a directional OCT system in which the pupil entry position of the narrow OCT beam can be varied across the dilated pupil of the eyes of the mice. The directional reflectivity of other retinal melanin-free layers, including the internal and external limiting membranes, and Bruch's membrane (albinos) were also measured and compared between the strains. The intensity of light backscattered from these layers was found highly sensitive to the angle of illumination, whereas the inner/outer segment (IS/OS) junctions showed a reduced sensitivity. The reflections from the RPE are largely insensitive in highly pigmented mice. The differences in directional scattering between strains shows that directionality decreases with an increase in melanin concentrations in RPE, suggesting increasing contribution of Mie scattering by melanosomes.
KW - directional scattering
KW - melanin
KW - optical coherence tomography
KW - retinal imaging
KW - retinal pigment epithelium
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U2 - 10.1117/1.JBO.24.6.066011
DO - 10.1117/1.JBO.24.6.066011
M3 - Article
C2 - 31254332
AN - SCOPUS:85068994316
VL - 24
JO - Journal of Biomedical Optics
JF - Journal of Biomedical Optics
SN - 1083-3668
IS - 6
M1 - 066011
ER -