Age-Related Macular Degeneration: Pathogenesis, Genetic Background, and the Role of Nutritional Supplements

Abstract

Age-related macular degeneration (ARMD) is the leading cause of severe vision loss and blindness worldwide, mainly affecting people over 65 years old. Dry and wet ARDM are the main types of the disease, which seem to have a multifactorial background. The aim of this review is to summarize the mechanisms of ARMD pathogenesis and exhibit the role of diet and nutritional supplements in the onset and progression of the disease. Environmental factors, such as smoking, alcohol, and, diet appear to interact with mutations in nuclear and mitochondrial DNA, contributing to the pathogenesis of ARMD. Inflammatory mediators and oxidative stress, induced by the daily exposure of retina to high pressure of oxygen and light radiation, have been also associated with ARMD lesions. Other than medical and surgical therapies, nutritional supplements hold a significant role in the prevention and treatment of ARMD, eliminating the progression of macular degeneration.

Potential Protective Effects of Metformin on Ocular Complications in Patients with Type 2 Diabetes

“…Those authors assumed metformin's protective role in development or progression of AMD based on both its antiinflammatory and antioxidative properties and on AMD pathogenesis. Namely, besides environmental and genetic factors, AMD pathogenesis involves inflammation and oxidative stress, which can lead to choroidal neovascularization and geographic atrophy with potential loss of vision [47][48][49][50].…”

Detrimental Effects of UVB on Retinal Pigment Epithelial Cells and Its Role in Age-Related Macular Degeneration

“…A key role of the retina is to convert light stimuli to neural impulses, which are then transmitted through the optic nerve to the occipital lobe [2]. The retina is made of the retinal pigment epithelium (RPE), Bruch's membrane, and a sensorineural layer which is also known as the sensory retina.…”

“…Daily exposure of our retina to oxygen and light; prolonged inflammation by harmful agents; and lifestyle choices like smoking, drinking alcohol, and our diet could contribute to mutations in nuclear and mitochondrial DNA. All these factors were suggested to be contributors to the pathogenesis of AMD [2].…”

“…Those who take photosensitizing drugs are also at increased risk of phototoxicity towards the RPE [18,19]. Besides that, places of higher altitudes were reported to increase by 30% in UVA and UVB exposure for every 2 Oxidative Medicine and Cellular Longevity 1000 m. For example, a person hiking Mount Everest would be exposed up to 133% more UVR in comparison to those at the summit of Mount Whitney. Snow too reflects about 80% of UVR, increasing further the detrimental effects of UVR [20].…”

Mimicking Peroxidase Activity by a Manganese(II) Complex Involving a New Asymmetric Tetradentate Ligand Containing Both Amino and Imino Groups

“…Oxidative stress causes uncontrolled oxidation of organic molecules with secondary alteration of their structure and biological functions, leading to the progressive deterioration and the collapse of organs and systems in the living organisms [1][2][3]. The superoxide dismutase, catalase, and peroxidase enzymes are part of the defense mechanisms against the reactive oxygen species generated by oxidative stress [4][5][6][7].…”