Transparency is essential for eyes, which serve as cameras. However, decreased transparency caused by accumulation of abnormal
proteins is commonly observed especially in elderly people. However, the mechanism of accumulation of abnormal
proteins in various ocular diseases is still unclear. In the present study, we investigated the role of D-
amino acids in the development of accumulation of abnormal
proteins in age-related ocular diseases. Whole eyes with
age-related macular degeneration were excised from four patients. Surgical specimens with
pinguecula were excised from eight patients, and specimens with climatic droplet keratopathy were excised from three patients. Polyclonal antibody to the D-beta-Asp-containing
peptide was prepared. Using the antibody, immunohistochemical localization of D-beta-Asp-containing
proteins was determined. In eyes with
age-related macular degeneration, accumulation of abnormal
proteins was observed between the
retinal pigment epithelial cells and Bruch's membrane. The accumulated abnormal
proteins were positive for D-beta-Asp-containing
peptides. In surgical specimens with
pinguecula and climatic droplet keratopathy, abnormal accumulation of
proteins seen in the superficial layer of the stroma was positive for D-beta-Asp-containing
peptide. The results indicate that development of D-beta-Asp-containing
proteins in vivo have a central role in the development of accumulation of abnormal
proteins in
age-related macular degeneration,
pinguecula, and climatic drop-like dystrophy.