Retinal ganglion cells (RGCs) are a heterogeneous population of neurons, comprised of numerous subtypes that work synchronously to transmit visual information to the brain. In blinding disorders such as glaucoma, RGCs are the main cell type to degenerate and lead to loss of vision. Previous studies have identified and characterized a variety of RGC subtypes in animal models, although only a handful of studies demonstrate the differential loss of these RGC subtypes in response to disease or injury. Thus, efforts of the current study utilized both chronic (bead occlusion) and acute (optic nerve crush, ONC) rat models to characterize disease response and differential loss of RGC subtypes. Bead occlusion and ONC retinas demonstrated significant RGC loss, glial reactivity and apoptosis compared to control retinas. Importantly, bead occlusion and ONC retinas resulted in differential subtype-specific loss of RGCs, with a high susceptibility for alpha- and direction selective-RGCs and preferential survival of ipRGCs. Results of this study serve as an important foundation for future experiments focused on the mechanisms resulting in the loss of RGCs in optic neuropathies, as well as the development of targeted therapeutics for RGC subtype-specific neuroprotection.

protection by sustained nanoparticle delivery of oncostatin M and ciliary neurotrophic factor into rodent models of retinal degeneration.

Purpose To present a new retinal layer segmentation technique, in order to evaluate the existence of nerve fiber hyperplasia in patients with the autosomal recessive spastic ataxia of Charlevoix‐Saguenay (ARSACS). Methods This observational cross‐sectional study included five patients with a molecular diagnosis of ARSACS and 5 sex and age‐matched healthy controls underwent a full ophthalmologic examination, which included a new technique to segment the retinal layers using Optical Coherence Tomography. Images and data were correlated with diffusion tensor colour encoded MRI maps, diffusion tensor tractographies, and retinal anatomopathological analysis. Results Every patient showed increased thickness in the internal layers of the retina (inner limiting membrane, nerve fiber layer and ganglion cell layer) in OCT evaluation. These findings suggest the presence of neurofilamentous hyperplasia in the retina of patients with ARSACS and correlated with anatomopathological findings. Conclusion We found evidence of ganglion cell and nerve fiber hyperplasia in the retina of ARSACS patients. Thus, a revision of the aetiopathogenic mechanisms is necessary in this disease.