Update on the Effects of Antioxidants on Diabetic Retinopathy: In Vitro Experiments, Animal Studies and Clinical Trials

Abstract

Current therapies for diabetic retinopathy (DR) incorporate blood glucose and blood pressure control, vitrectomy, photocoagulation, and intravitreal injections of anti-vascular endothelial growth factors or corticosteroids. Nonetheless, these techniques have not been demonstrated to completely stop the evolution of this disorder. The pathophysiology of DR is not fully known, but there is more and more evidence indicating that oxidative stress is an important mechanism in the progression of DR. In this sense, antioxidants have been suggested as a possible therapy to reduce the complications of DR. In this review we aim to assemble updated information in relation to in vitro experiments, animal studies and clinical trials dealing with the effect of the antioxidants on DR.

Clinical and Molecular-Genetic Insights into the Role of Oxidative Stress in Diabetic Retinopathy: Antioxidant Strategies and Future Avenues

“…It has also been said that early oral supplementation with nutraceuticals provides a significant health benefit to prevent DR progression because of its antioxidant and anti-inflammatory properties, reducing both the neural and vascular damage caused in the retina by the hyperglycemia [ 7 , 12 , 19 , 62 , 63 ]. The combined A/ω3 formula used herein strongly supported the descriptions of the above authors and our previous works [ 19 , 35 , 39 , 40 , 49 ] on the processes of retinal neuroprotection and vasculoprotection. Moreover, Amato et al [ 64 ] emphasized the possible side effects of systemic neuroprotectants as well as doubts about the appropriate retinal bioavailability of these substances in contrast with the intravitreal injections.…”

“…In fact, the European Union ROS consortium (EU-ROS) stated in 2017 that many diseases had been found to be associated with OS, and subsequently, the theory that OS-related pathologies can be corrected by antioxidant therapy was launched [ 47 ]. However, while experimental studies support this theory, clinical studies still generate controversial results [ 48 , 49 ]. In our opinion, the possibility remains that biotherapies based on the redox changes occurring in diabetics may help to protect the retina.…”

Diabetic Retinopathy: The Role of Mitochondria in the Neural Retina and Microvascular Disease

“…Despite the evidence that antioxidants can slow the progression of DR, clinical trials have had mixed results. This topic was very recently reviewed by Garcia-Medina et al [ 218 ], but is summarized here for completeness. The most successful interventions have been those that use combined antioxidant therapy (CAT).…”

Computational Analysis of Clinical and Molecular Markers and New Theranostic Possibilities in Primary Open-Angle Glaucoma

“…In this context, the fatty acid amide hydrolase inhibitors and endocannabinoid system were investigated as glaucoma neuroprotectans [72]. An interesting review [73] focused on endogenous neuroprotective factors involved in RGCs survival, covering new therapeutic strategies, as the ones suggested herein. In a similar manner, recent reports discussed promising neuroprotectant candidates for preventing glaucomatous RGC death [74,75].…”