Recent Developments in Diabetic Retinal Neurodegeneration: A Literature Review

Abstract

Neurodegeneration plays a significant role in the complex pathology of diabetic retinopathy. Evidence suggests the onset of neurodegeneration occurs early on in the disease, and so a greater understanding of the process is essential for prompt detection and targeted therapies. Neurodegeneration is a common pathway of assorted processes, including activation of inflammatory pathways, reduction of neuroprotective factors, DNA damage, and apoptosis. Oxidative stress and formation of advanced glycation end products amplify these processes and are elevated in the setting of hyperglycemia, hyperlipidemia, and glucose variability. These key pathophysiologic mechanisms are discussed, as well as diagnostic modalities and novel therapeutic avenues, with an emphasis on recent discoveries. The aim of this article is to highlight the crucial role of neurodegeneration in diabetic retinopathy and to review the molecular basis for this neuronal dysfunction, its diagnostic features, and the progress currently made in relevant therapeutic interventions.

Diabetes Mellitus Associated Progressive Neurovascular Retinal Injury: Recommendations for Imaging and Functional Testing and Potential Role for Early Intervention with Modern Retinal Laser Therapy

“…This review will focus primarily on the effects of traditional and newer methods of retinal laser treatment upon the progressive neurovascular injury caused by diabetes as well as potential methods for initiation earlier in the course when microvascular injury and neuronal apoptosis are reversible. For a more comprehensive discussion of traditional hyperglycemia treatments as well as newer systemic treatments currently available or under clinical evaluation for treating the retina as well as brain neurovascular occlusive and inflammatory injury the reader is referred to these excellent review articles [87,[164][165][166][167][168].…”

Neurodegeneration as an Early Sign of Diabetic Retinopathy

“…These are the factors of how Diabetic Retinal Neurodegeneration (DRN) occurs. 11 Disturbances of the neurosensory retina in diabetes can take place through various mechanisms, which are divided into inflammatory, metabolic, genetic/epigenetic. Hyperglycemic condition alters the biochemical pathway (elevation of polyol pathway, hexosamine pathway, protein kinase C [PKC], and advanced glycation end-products [AGEs]), which will induce the apoptosis of ganglion, amacrine, and Müller cells.…”

“…These are the primary factors in the process of ocular neurodegeneration. 8,11,12 The first noticeable change in diabetes is the decline of astrocyte cell count and changes in protein expression with the ensuing inner retina hypoxia and functional deficit in ganglion cell response. The Müller cell dysfunction due to chronic hyperglycemia leads to the release of numerous growth factors and cytokines.…”

Ocular Neurodegenerative Diseases: Interconnection between Retina and Cortical Areas

“…Diabetic retinopathy (DR) is a complication of diabetes that affects the eyes, causing severe visual impairment. It is induced by damage to the blood vessels in the light-sensitive part of the eye, the retina, with the vasculopathy being the main involved pathophysiologic mechanism [ 15 ]. It can develop in subjects affected by both type 1 and type 2 diabetes.…”

“…Neurodegeneration plays a significant role in the complex pathology of diabetic retinopathy. Evidence suggests the onset of neurodegeneration occurs early on in such disease [ 15 , 16 ]. Retinitis pigmentosa is a retinal dystrophy.…”