Identification of Retinal Amyloid-Beta in Ex-Vivo Human Glaucoma Eyes Using a Novel Ocular Tracer.

Abstract

Purpose: To characterize the presence of amyloid-beta (Aβ) in human glaucoma retina and to test identification of retinal Aβ using a novel fluorescent Aβ-binding small molecule (AMDX-2011).

Methods: Post-mortem human eyes with (n=4) and without (n=4) glaucoma were acquired from an eye bank. Retinas were dissected, flat-mounted, and fixed. Using the flat-mounts, immunofluorescence was performed against Aβ, AMDX-2011 staining was conducted, and images were acquired using fluorescence microscopy.

Results: Fluorescence microscopy demonstrated presence of Aβ signal that co-localized with AMDX-2011 staining in glaucoma retina. Co-labeled puncta appeared in all quadrants of the retina, including retina temporal to the optic nerve. The puncta were mainly located within the inner layers of the retina. Glaucoma retinas had more co-labeled puncta than control retinas in all locations (P = 0.002-0.02). Co-labeled puncta were also larger in the superior quadrant of glaucoma compared to control retinas (P = 0.02).

Conclusions: Aβ was detected in human glaucomatous retina, and its distribution was mapped. AMDX-2011 identification of Aβ may lead to future diagnostic tests aimed at detecting Aβ in glaucoma patients.