Abstract
Purpose: :
To study crystalline lenses from donors with Alzheimer's disease (AD) in order to evaluate the presence of cataract and beta-amyloid.
Methods: :
We obtained 31 lenses from 17 donors with AD and 15 lenses from age-matched controls provided by the Banco de Ojos para Tratamientos de la Ceguera (Barcelona, Spain). The controls included 7 donors with cortical cataracts and 8 donor with transparent lenses. All lenses were photographed in a dark field microscope. Histological sections were analysed with classical and a modified, more sensitive Congo red staining, thioflavin staining, and by immunohistochemestry. Brain tissue from a donor with AD and a cornea with a lattice dystrophy were used as controls for the staining techniques.
Results: :
From the 17 donors with AD, 9 had cortical cataract and 8 did not have cataract. Classical and modified Congo red, and thioflavin staining were positive in the control tissues. Immunohistochemestry staining was positive in the brain tissue but not in the cornea sample. Every staining technique performed in the lenses from this study was negative for beta-amyloid.
Conclusions: :
The results in our control tissues correspond well with known observations in the brain and cornea. The absence of staining of the AD and control lenses with the techniques employed makes us conclude that there is no classical amyloid in lenses from donors with AD and in control cortical cataracts.
Keywords: cataract • aging • microscopy: light/fluorescence/immunohistochemistry