A low degree of polarization uniformity (DOPU) and high double pass phase retardation (DPPR) values below the retinal-pigment epithelium – Bruch membrane’s (RPE-BM) complex in the human retina have been associated with the presence of melanin. Our polarimetry measurements (Cense et al, JBP, 2018) found no correlation between melanin and lower DOPU, because all young subjects had high DOPU values, but saw decreased DOPU in a subset of older subjects, who also have melanin. We hypothesize that this signal is not induced by melanin, but by a substance related to hypertension. Our measurements demonstrated a strong correlation between hypertensives and high DPPR values induced by the RPE-BM complex, suggesting that the induced retardance is the result of physiological changes associated with hypertension. This signal may be useful as a biomarker for screening of cardiovascular diseases.
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