No proof for retinal amyloid after oral curcumin in amyloid confirmed AD cases

INTRODUCTIONPrevious work showed in-vivo presence of retinal amyloid in AD patients using curcumin. We aimed to replicate these findings in an amyloid biomarker confirmed cohort. METHODSTwenty-six AD patients (age 66 ({+/-}9), MMSE[≥]18) and 14 controls (age 71({+/-}12)) used three curcumin formulations: Longvida(R), Theracurmin(R) and Novasol(R). Plasma levels were determined and pre- and post-curcumin retinal scans acquired using autofluorescence imaging. Images were both visually and quantitatively assessed. RESULTSVisual assessment showed no difference between AD patients and controls for pre- and post-curcumin images. This was confirmed by quantitative analyses. Mean plasma curcumin levels were 198.7 nM (Longvida(R)), 576.6 nM (Theracurmin(R)) and 1605.8 nM (Novasol(R)). DISCUSSIONWe found no difference in retinal focal fluorescence in an amyloid biomarker confirmed cohort of AD patients and controls, using Longvida(R) (previously used for this purpose) and two additional curcumin formulations yielding higher curcumin plasma levels. We therefore question the presence of retinal amyloid.