Macular Pigment, Visual Function, and Macular Disease among Subjects with Alzheimer's Disease: An Exploratory Study

• Published in: Journal of Alzheimer's disease Vol. 42; no. 4; pp. 1191 - 1202
• Main Authors: Nolan, John M., Loskutova, Ekaterina, Howard, Alan N., Moran, Rachel, Mulcahy, Riona, Stack, Jim, Bolger, Maggie, Dennison, Jessica, Akuffo, Kwadwo Owusu, Owens, Niamh, Thurnham, David I., Beatty, Stephen
• Format: Journal Article
• Language: English
• Published: London, England SAGE Publications 01.01.2014
• Subjects: Aged; Aged, 80 and over; Alzheimer Disease - pathology; Alzheimer Disease - physiopathology; Alzheimer Disease - psychology; Diet; Female; Humans; Lutein - administration & dosage; Lutein - blood; Macular Degeneration - pathology; Macular Degeneration - physiopathology; Macular Pigment - metabolism; Male; Middle Aged; Neuropsychological Tests; Retina - pathology; Visual Acuity; Zeaxanthins - administration & dosage; Zeaxanthins - blood; cognitive function; Age-related macular degeneration; meso-zeaxanthin; Alzheimer's disease; lutein; contrast sensitivity; visual function; zeaxanthin
• ISSN: 1387-2877; 1875-8908
• DOI: 10.3233/JAD-140507

Background: The macula (central retina) contains a yellow pigment, comprising the dietary carotenoids lutein (L), zeaxanthin (Z), and meso-zeaxanthin, known as macular pigment (MP). The concentrations of MP’s constituent carotenoids in retina and brain tissue correlate, and there is a biologically-plausible rationale, supported by emerging evidence, that MP’s constituent carotenoids are also important for cognitive function. Objective: To investigate if patients with Alzheimer’s disease (AD) are comparable to controls in terms of MP and visual function. Methods: 36 patients with moderate AD and 33 controls with the same age range participated. MP was measured using dual-wavelength autofluorescence (Heidelberg Spectralis®); cognitive function was assessed using a battery of cognition tests (including Cambridge Neuropsychological Test Automated Battery). Visual function was recorded by measuring best corrected visual acuity (BCVA) and contrast sensitivity (CS). Serum L and Z concentrations (by HPLC) and age-related macular degeneration (AMD, by retinal examination) status were also assessed. Results: In the AD group, central MP (i.e., at 0.23°) and MP volume were significantly lower than the control group (p < 0.001 for both), as were measures of BCVA, CS, and serum L and Z concentrations (p < 0.05, for all). Conclusion: AD patients were observed to exhibit significantly less MP, lower serum concentrations of L and Z, poorer vision, and a higher occurrence of AMD when compared to control subjects. A clinical trial in AD patients designed to investigate the impact of macular carotenoid supplementation with respect to MP, visual function, and cognitive function is merited.