Given the success of
Volume I of this Research Topic, we are pleased to announce the launch of Volume II: “Neurodegeneration and Neuroprotection in Retinal Disease, Volume II”.
Retinal diseases represent a burden with high social and economic impact in both developed and developing countries, affecting a considerable number of working-age adults. Vision loss is caused by the death of retinal neurons, however, the causes and the mechanisms leading to neuronal death are far from being fully elucidated.
Neurodegeneration is a distinctive trait of retinal pathologies like glaucoma, diabetic retinopathy, age-related macular degeneration, and retinitis pigmentosa. The pathophysiological characteristics of these diseases may differ, however, common mechanisms can be identified and they may include the occurrence of oxidative stress and/or of inflammation, which would ultimately cause neuronal death. The elucidation of the pathophysiological mechanisms of these retinal diseases should also take into account multiple additional factors that could affect neuronal survival, such as, but not limited to, the occurrence of excitotoxicity, the involvement of vascular endothelial growth factor or of other growth factors, the role of glial cells, the disruption of the neurovascular unit, endoplasmic reticulum stress, mitochondrial dysfunction, the role of autophagy.
Although much remains to be discovered about the causes and the impact of neurodegeneration on different retinal pathologies, in the last few years the idea that a neuroprotective approach may provide substantial benefits in retinal diseases has been established and has been the subject of a significant number of publications. A variety of factors with documented neuroprotective effects in in vitro or in vivo retinal models has been investigated and new factors and new evidence are being collected almost every day. The search for new neuroprotective substances for testing as treatments of retinopathies is focused on activators/inhibitors of neurotransmitter systems at the level of specific receptors or of signal transduction mechanisms, on putative antioxidant or anti-inflammatory molecules, on growth factors, on autophagy modulators, and on the preservation of the neurovascular unit. Of particular interest, in this respect, are the investigations on substances of natural origin (nutraceuticals) that are used in traditional medicine or that have been discovered more recently.
Last, but not least, is the necessity of the development of new methods of drug administration that may allow efficient drug delivery to the retina. These may include new formulations of eye drops, intraocular implants or intraocular administrations of nanoparticle-associated drugs for prolonged, slow drug delivery to the retina.
This Research Topic collects review or original papers representing the state of the art in terms of i) elucidation of the pathophysiological mechanisms of neurodegeneration in retinal diseases; ii) new neuroprotective substances, with a particular attention to nutraceuticals, that may be used to treat retinal pathologies; iii) new methods of neuroprotective drug delivery to the retina.