Oxidative stress in dry age-related macular degeneration and exfoliation syndrome

Abstract

Oxidative stress refers to cellular or molecular damage caused by reactive oxygen species, which especially occurs in age-related conditions as a result of an imbalance between the production of reactive oxygen species and the antioxidant defense response. Dry age-related macular degeneration (AMD) and exfoliation syndrome (XFS) are two common and complex age-related conditions that can cause irreversible vision loss. Two subtypes of AMD, which is the leading cause of blindness in the Western world, exist: the most prevalent dry type and the most severe wet type. Early dry AMD is characterized by formation of drusen, which are sub-retinal deposits, in the macular area and may progress to geographic atrophy with more dramatic manifestation. XFS is a systemic disorder of the extracellular matrix characterized by the accumulation of elastic fibrils that leads, in most cases, to glaucoma development with progressive and irreversible vision loss. Due to the aging population, the prevalence of these already-widespread conditions is increasing and is resulting in significant economic and psychological costs for individuals and for society. The exact composition of the abnormal drusen and XFS material as well as the mechanisms responsible for their production and accumulation still remain elusive, and consequently treatment for both diseases is lacking. However, recent epidemiologic, genetic and molecular studies support a major role for oxidative stress in both dry AMD and XFS development. Understanding the early molecular events in their pathogenesis and the exact role of oxidative stress may provide novel opportunities for therapeutic intervention for the prevention of progression to advanced disease.

Dietary fatty acids and lipoproteins on progression of age-related macular degeneration

“…Moreover, over 40% of drusen have lipid components, mainly phosphatidylcholine and cholesterol (Wang et al, 2010). In agreement with the hypothesis that oxidative stress promotes to AMD pathology, compounds of lipid oxidation are highly abundant in AMD drusen (Chiras et al, 2015).…”

One protein, multiple pathologies: multifaceted involvement of amyloid β in neurodegenerative disorders of the brain and retina

“…Epidemiologic, genetic, and biochemical studies support a role for oxidative stress in AMD pathogenesis and RGC and ON damage in glaucoma. The macular region is particularly exposed to the high levels of oxidative stress that is One protein, multiple pathologies: multifaceted involvement of amyloid b in… increased with ageing [109]. Lipofuscin deposition in AMD is believed to further augment this by inducing an increased level of free radical formation.…”

Brimonidine Can Prevent In Vitro Hydroquinone Damage on Retinal Pigment Epithelium Cells and Retinal Müller Cells

“…17 Oxidative stress and inflammation are believed to be possible mechanisms for this association. 18,19 Cigarette smoke contains thousands of toxic and carcinogenic chemicals, 20,21 which can be divided into 2 categories: the gas-phase smoke components and substances retained in the filter (referred to tar). The most common component in cigarette tar is hydroquinone (HQ), semiquinone mixture.…”