Imaging retinal melanin: a review of current technologies

• Published in: Journal of biological engineering Vol. 12; no. 1; p. 29
• Main Authors: Lapierre-Landry, Maryse, Carroll, Joseph, Skala, Melissa C
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 04.12.2018; BioMed Central; BMC
• Subjects: Age; Aging; Albinism; Autofluorescence; Choroid; Disease; Epithelium; Fundus reflectometry; Image contrast; Image detection; Imaging techniques; In vivo methods and tests; Infrared imaging; Infrared photography; Macular degeneration; Medical imaging; Melanin; Melanosomes; Optical Coherence Tomography; Optical tomography; Photoacoustic; Photography; Photoreceptors; Physiological aspects; Pigmentation; Reflectometry; Researchers; Retina; Retinal pigment epithelium; Review; Tomography; Iran; United States; Photoacoustic; Polarization; Optical coherence tomography; Autofluorescence; Near-infrared; Choroid; Retina; Fundus reflectometry; Photothermal; Retinal pigment epithelium
• ISSN: 1754-1611; 1754-1611
• DOI: 10.1186/s13036-018-0124-5

The retinal pigment epithelium (RPE) is essential to the health of the retina and the proper functioning of the photoreceptors. The RPE is rich in melanosomes, which contain the pigment melanin. Changes in RPE pigmentation are seen with normal aging and in diseases such as albinism and age-related macular degeneration. However, most techniques used to this day to detect and quantify ocular melanin are performed ex vivo and are destructive to the tissue. There is a need for in vivo imaging of melanin both at the clinical and pre-clinical level to study how pigmentation changes can inform disease progression. In this manuscript, we review in vivo imaging techniques such as fundus photography, fundus reflectometry, near-infrared autofluorescence imaging, photoacoustic imaging, and functional optical coherence tomography that specifically detect melanin in the retina. These methods use different contrast mechanisms to detect melanin and provide images with different resolutions and field-of-views, making them complementary to each other.