Neovascular Age-Related Macular Degeneration and its Association with Alzheimer's Disease

In developed countries, people of advanced age go permanently blind most often due to age-related macular degeneration, while at the global level, this disease is the third major cause of blindness, after cataract and glaucoma, according to the World Health Organisation. The number of individuals believed to suffer from the disease throughout the world has been approximated at 50 million. Age-related macular degeneration is classified as non-neovascular (dry, non-exudative) and neovascular (wet, exudative). The exudative form is less common than the non-exudative as it accounts for approximately 10 percent of the cases of the disease. However, it can be much more aggressive and could result in a rapid and severe loss of central vision. Similarly, with age-related macular degeneration, Alzheimer's disease is a late-onset, neurodegenerative disease affecting millions of people worldwide. Both of them are associated with age and share several features, including the presence of abnormal extracellular deposits associated with neuronal degeneration, drusen, and plaques, respectively. The present review article highlights the pathogenesis, clinical features, and imaging modalities used for the diagnosis of neovascular age-related macular degeneration. A thorough overview of the effectiveness of anti-VEGF agents as well as of other treatment modalities that have either lost favour or, are rarely used, is provided in detail. Additionally, the common histologic, immunologic, and pathogenetic features of Alzheimer's disease and age-related macular degeneration are discussed in depth.