The Aging Retina in the Context of Cerebral Neurodegenerative Diseases

Background Neurodegenerative diseases (ND) consist of divers affections of the central nervous system related to etiology, localization, and of course of the disease. Alzheimer's disease (AD) and related dementias are best investigated together with socioeconomic conditions and play an important role in its high prevalence. This work will present ND diseases in the context of analogous retinal degeneration mechanisms and ophthalmological diseases. Methods Based on epidemiological data, the current neurological bibliography of ND has been considered. Additional ophthalmological data containing age-related retinal diseases were included in a comparative manner. Moreover, our own data dealing with similarities of cellular and molecular biomarkers in the retinal and cerebral aging process were included. Results AD is the most important neurological ND disease with increasing prevalence. Age-related macular degeneration (AMD) and glaucoma are the most common retinal diseases with ND background and have an increasing prevalence. Irreversible loss of neurons, together with glial, microglial, extracellular, and vascular reactions are found both in the brain and retina and can show atrophic signs with onsets of plaques (AD), drusen (AMD) or optic degenerations. Alterations of cellular conditions result in irreversible functional impairments. Current therapeutic options preserve only residual function and preventive possibilities are actually missing. Molecular biomarkers have been identified to endorse a better understanding of ND and to provide new therapeutic options. Conclusions Comparison of cerebral AD shows similarities with retinal AMD, and cerebral dementias are comparable with the physiological age-related impairment of visual acuity. Optic degeneration may be similar to cerebral atrophy associated with retroocular compression. Improved understanding of pathogenetic mechanisms of cerebral and retinal diseases may help to establish preventive and therapeutic concepts in the future.