Retinal ganglion cells in diabetes

Abstract

Diabetic retinopathy has long been recognized as a vascular disease that develops in most patients, and it was believed that the visual dysfunction that develops in some diabetics was due to the vascular lesions used to characterize the disease. It is becoming increasingly clear that neuronal cells of the retina also are affected by diabetes, resulting in dysfunction and even degeneration of some neuronal cells. Retinal ganglion cells (RGCs) are the best studied of the retinal neurons with respect to the effect of diabetes. Although investigations are providing new information about RGCs in diabetes, including therapies to inhibit the neurodegeneration, critical information about the function, anatomy and response properties of these cells is yet needed to understand the relationship between RGC changes and visual dysfunction in diabetes.

Figure 1. Retinal ganglion cell abnormalities in retinas from diabetic Ins2^Akita mice

Ins2^Akita and Thy1-YFP mice were crossbred to produce spontaneously diabetic animals with endogenous expression of the yellow fluorescent protein in a subset of RGCs. Cells were imaged by confocal microcopy (Leica TCS SP2 AOBS) and rendered as maximum projections from z-stacks that included the axon and entire dendritic field. Abnormal features were noted in the ganglion cells of retinas from mice that were diabetic for three months. The abnormalities included axonal swellings (short arrows) and associated constriction (long arrows), as well as enlarged cell bodies and increased dendritic branches and terminals. A, medium ON-RGC; B, large ON-RGC (Gastinger et al. 2008).