Eyes with cortical opacification show higher Aβ1-43
Japanese patients with cortical opacification have high levels amyloid β1-43 (Aβ1-43) in their lens epithelium, a new study has found.
Normal (controls n=19; mean age 62.8±3.6 years) and opaque (cataract cases n=78; mean age 72.7±1.1 years) lenses were collected from Japanese individuals without diabetes mellitus or Alzheimer’s disease. Levels of Aβ1-40, Aβ1-42, and Aβ1-43 were measured from the samples.
Lens samples were classified according to cataract type: cortical cataract (COR), nuclear cataract (NUC), posterior subcapsular cataract (PSC), retrodots (RD), water clefts (WC), posterior subcapsular opacification, cortical opacification and mixed cataracts with cortical opacification (RD + WC).
There were no significant differences in the levels of Aβ1-40 and Aβ1-42 between controls and patients with WC, RD, PSC, NUC and COR cataracts. On the other hand, Aβ1-43 was not detectable in lenses from controls and PC or WC cataract patients.
Moreover, Aβ1-43 was present only in very low concentrations in the samples from NUC and RD cataract patients. In COR cataracts, Aβ1-43 concentration was 18.5- and 13.9-fold higher than in NUC and WC cataracts, respectively.
The ratio of Aβ1-43 to total Aβ in patients with COR cataract was higher than in NUC, PSD, WC, RD and control participants.
Aβ1-43 levels and Aβ1-43-to-total-Aβ ratio were 26.1- and 13.6-fold higher in mixed cataract patients with cortical opacification than in mixed cataract patients without cortical opacification, respectively.
There were no apparent differences in Aβ1-40, Aβ1-42 and total Aβ concentrations between controls and mixed cataract patients with or without cortical opacification.