Oxidative stress and visual system: a review

Abstract

Different types of tissues respond differently to the action of oxidative stress. The visual system is very sensitive to oxidative action due to continuous exposure to light. In consideration of the growing interest of scientific studies towards various compounds endowed with antioxidant and anti-inflammatory properties, we performed a review of the literature focusing on the use of some antioxidant molecules for the treatment of conditions affecting the visual system. In this study, we focused on the ability of two antioxidant agents, the small molecule α-lipoic acid (ALA) and the enzyme superoxide dismutase (SOD), to influence the neurodegenerative physiological processes related to aging and oxidative stress affecting the ocular segment. The literature data report that ALA and SOD can protect against neurodegenerative effects both the optic nerve and retina and, if administered together, they are able to lower the levels of oxidative stress, thus preventing neurodegeneration and reducing the apoptotic process.

Vitamin B3 Provides Neuroprotection via Antioxidative Stress in a Rat Model of Anterior Ischemic Optic Neuropathy

“…The ON infarction induced oxidative stress that degraded the antioxidant capacity of SOD [ 27 ]. Seven days after the infarction, the SOD activity in the PBS-treated group was 1.6-fold lower than that in the sham group ( Figure 5 A).…”

Oxidative Stress: A Suitable Therapeutic Target for Optic Nerve Diseases?

“…NOS generates nitric oxide (NO), while NOX (comprising seven isoforms: NOX1, -2, -3, -4, -5, DUOX1, -2) transfers electrons from cytosolic NADPH to molecular O₂, generating O2 •− [78]. Superoxide serves as the precursor of most other ROS [73], which can be categorized into "free radicals" such as hydroxyl ( • OH), alkoxyl (RO • ), peroxyl (ROO • ), hydroperoxyl (HOO • ) radical [36], characterized by an unpaired electron at the outer orbital level [79]. Additionally, there are "non-radical oxidizing chemical species" such as hydrogen peroxide (H₂O₂), hypochlorous acid (HOCl), ozone (O3), and singlet oxygen ( 1 △g) [36], which have electron pairs in covalent binding [79].…”

Inclusion of carotenoids in dietary habits as an alternative to prevent age-related macular degeneration

“…It should be considered that the retina has an oxygen rich environment, in addition to prolonged exposure to light, leading to the continuous production of free radicals ( 17 ). To reduce this damage to the retinal epithelium, there are enzymatic mechanisms that maintain homeostasis ( 18 ). Due to aging, the retina has a weakened antioxidant system, making it susceptible to oxidation, manifesting itself as hard exudates in the periphery, thickening of Brunch's membrane, and thinning of the choriocapillaris ( 15 ).…”