Purchase this article with an account.
T Nishiyama, S Umeda, MT Suzuki, Y Yoshikawa, A Yasosima, F Iwata, K Fujiki, A Kanai, Y Tanaka, T Iwata; Histopathological Study of Drusen Observed in Cynomolgus Monkey (Macaca fascicularis) . Invest. Ophthalmol. Vis. Sci. 2002;43(13):2791.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Purpose: To characterize the properties of drusen observed in cynomolgus monkeys by histopathological methods. Methods: Sixty monkeys aged between 15 to 24 years in propagation colonies were examined by funduscope. Eyes were collected from ten monkeys diagnosed as macular degeneration. Histological tissue sections prepared from excised macular retina were investigated under light microscopy after staining by HE (hematoxylin and eosin), PAS (periodic acid sciff), LFB (luxol fast blue) and MT (masson trichrome). Autofluorescence was also observed under same microscope. Ultrastructure of drusen was examined by transmission electron microscopy. Results: Retinal pigment epithelium (RPE) showed hyper-pigmentation and scattered cytoplasmic vacuolation. Strong autofluorescence and many PAS-positive granules in the cytosol were also observed. These observations indicate that lipofuscin granules are highly accumulated in RPE. Soft drusen were detected in half of the ten monkeys analyzed. In one of the severely affected monkey, thick layer of drusen around fovea was observed. All drusen were PAS-positive, indicating the inclusion of saccharide. In some large dome-shape drusen, spherical structures were observed. These structures appeared more eosinophilic and showed stronger autofluorescence. Phospholipid components were detected in these structures by LFB stain. MT stain excluded collagen fibers as components of all observed drusen. Under electron microscopy, drusen appeared to be sponge-like structures consisted of rough reticular materials with scattered electrodense microparticles. Conclusion: Drusen observed in affected monkeys were histologically similar to that of human. These drusen contained rough reticular materials with scattered microparticles. Saccharide and phospholipid compositions were detected by PAS and LFB stain respectively.
This PDF is available to Subscribers Only