Relationship of Area of Soft Drusen in Retina with Cerebral Amyloid-β Accumulation and Blood Amyloid-β Level in the Elderly

J Alzheimers Dis. 2018;62(1):239-245. doi: 10.3233/JAD-170956.

Abstract

Background: Histopathological studies have confirmed that soft drusen contains amyloid-β (Aβ).

Objective: To examine the relationship between the area of soft drusen in the macular area and cerebral Aβ accumulation or plasma Aβ level in elderly persons without dementia.

Methods: Fourteen consecutive patients (18 eyes) aged ≥50 years with macular soft drusen were studied prospectively. From color fundus photographs, the area of soft drusen (pixel) within a 6,000 μm diameter with the macula as center was measured. Standard uptake value ratio (SUVR) was obtained from positron emission tomography using florbetapir, which indicates the ratio of cerebral cortical-to-cerebellar Aβ accumulation. Ratio of plasma Aβ1-42 to Aβ1-40 level was calculated.

Results: Mean age was 73.3±7.6 years. The soft drusen area was 4.32±2.42 mm2. The SUVR was 1.08±0.15. Plasma Aβ1-42/Aβ1-40 ratio was 0.17±0.08. When SUVR ≥1.10 was defined as positive and <1.10 as negative, the soft drusen area in SUVR-positive patients (6.19±1.14 mm2) was significantly (p = 0.0043) larger than that in SUVR-negative patients (3.13±2.27 mm2). Multivariate regression analysis showed that SUVR positivity correlated with soft drusen area (p = 0.0484) and with Voxel-based Specific Regional Analysis System for Alzheimer's Disease score (p = 0.0360). However, there was no correlation with gender (p = 0.1921), age (p = 0.2361), Alzheimer's Disease Assessment Scale score (p = 0.6310), Mini-Mental State Examination score (p = 0.4246), or plasma Aβ1-42/Aβ1-40 ratio (p = 0.8398).

Conclusion: Among elderly persons without dementia, the area of soft drusen was larger in those with more extensive cerebral Aβ accumulation. The area of soft drusen may be a biomarker of cerebral Aβ accumulation.

Keywords: Alzheimer’s disease; amyloid; dementia; florbetapir; macular degeneration; positron-emission tomography.

Publication types

  • Observational Study

MeSH terms

  • Aged
  • Aged, 80 and over
  • Amyloid beta-Peptides / metabolism*
  • Aniline Compounds
  • Biomarkers / metabolism
  • Brain / diagnostic imaging
  • Brain / metabolism*
  • Ethylene Glycols
  • Female
  • Humans
  • Male
  • Middle Aged
  • Positron-Emission Tomography
  • Prospective Studies
  • Radiopharmaceuticals
  • Retina / metabolism*
  • Retina / pathology
  • Retinal Drusen / metabolism*
  • Retinal Drusen / pathology

Substances

  • Amyloid beta-Peptides
  • Aniline Compounds
  • Biomarkers
  • Ethylene Glycols
  • Radiopharmaceuticals
  • florbetapir