Antioxidants and the Integrity of Ocular Tissues

Abstract

Oxygen-derived free radicals are normally generated in many pathways. These radicals can interact with various cellular components and induce cell injury. When free radicals exceed the antioxidant capacity, cell injury causes diverse pathologic changes in the organs. The imbalance between the generation of free radicals and antioxidant defence is known as oxidative stress. The eye can suffer the effect of oxidative damage due to the etiopathogenesis of some pathological changes related to oxidative stress. This paper reviews the role of oxidative stress in the onset and progression of damage in different eye structures, the involvement of the antioxidant network in protecting and maintaining the homeostasis of this organ, and the potential assessment methodologies used in research and in some cases in clinical practice.

Yttrium oxide nanoparticles prevent photoreceptor death in a light-damage model of retinal degeneration

“…One of them is the return of excited electrons to the ground state while the other option is to disperse through several interactions into ROS. PR cells have abundant polyunsaturated fatty acids (PUFA) which undergo lipid peroxidation in the presence of toxic ROS [3, 7, 8], eventually resulting in extensive damage to the membranous structures of the PR outer segment. In this study we clearly demonstrate that Y 2 O 3 NPs possess direct free radical scavenging activity, supporting the idea that reduction in oxidative stress underlies Y 2 O 3 -mediated protection of photoreceptor cells from light-mediated damage.…”

“…This can severely damage multiple cellular processes, disrupt cellular physiology, and activate apoptosis. In PRs, the high levels of polyunsaturated fatty acids (PUFA) are particularly susceptible to lipid peroxidation [3, 7, 8], and oxidative damage to proteins, RNA, and DNA can also occur [4, 7]. …”

Hypoxia–Reoxygenation Affects Whole-Genome Expression in the Newborn Eye

“…ROS is the most relevant free radical in eye disease and affects the cell integrity because DNA, proteins, and lipids are damaged during this process. 30 The ocular tissue has a protective function against oxidative damage, 30 but the immature antioxidant state of the premature newborns make them especially vulnerable. 31 Oxidative stress has long been implicated in the development of ROP by generating excessive amounts of ROS due to a fluctuating oxygen tension, unstable metabolism, and high concentration of polyunsaturated fatty acids in the photoreceptors.…”

Nrf2 Is an Attractive Therapeutic Target for Retinal Diseases

“…The final common pathway in a variety of retinal diseases, including glaucoma and retinitis pigmentosa, is linked to retinal cellular death, and it is likely that ROS triggers cellular damage in these cases. Factors such as an abundance of polyunsaturated lipids, high oxygen consumption ratio, hypoxia, psychological stress, radiation, air pollution including ozone, smoking, and oxidized foods are other typical risk factors that can induce the generation of ROS in the retina [13–16]. …”