Retinal vascular changes and systemic diseases: corrosion cast demonstration

The purpose of the present study is to clarify the specific retinal vascula r changes in rat models of single spontaneous or hereditary systemic diseas es. We used Wistar Kyoto (WKy) rats 6 months of age as normal controls, 24-mont h-old Wistar Kyoto rats in studies of aging, 16-month-old spontaneously hyp ertensive rats (SHR), 18-month-old rats with inherited hypercholesterolemia (RICO) for arteriosclerosis, and 18-month-old Otsuka Long-Evans Tokushima Fatty (OLETF) rats for diabetes mellitus. Retinal vascular corrosion casts were made and observed with a scanning electron microscope. The retinal ves sels were also examined with a transmission electron microscope. Specific changes in the retinal vessels were: narrowing and thin thread-lik e capillaries in aging; capillary tortuosity, irregularity and narrowing in hypertension; straightening in hypercholesterolemia; and loop formation an d microaneurysms in diabetes mellitus. These specific changes in the retinal vessels in each systemic disease can be clearly and easily revealed in a three-dimensional fashion by corrosion casts followed by scanning electron microscopy.