El ojo una ventana al cerebro

Resumo

Over the years, scientists have inquired about the concept that "eyes are the mirror of the soul"; looking for scientific evidence to determine whether eye research could be useful for brain research and diagnosis of their diseases. Alzheimer's disease (AD), Parkinson's disease (PD), and glaucoma are neurodegenerative diseases that have several common biological characteristics: their increased incidence in elderly, loss of specific neuronal populations, and protein aggregation. In addition, they share pathogenic mechanisms such as oxidative stress, mitochondrial damage, glutamate excitotoxicity, protein aggregation and glial activation; all of which will lead to cell death by apoptosis. The first abnormalities in the visual system in AD were observed in the 1970s, and were initially considered strictly as a cortical dysfunction. Studies over the past 30 years have revealed that all parts of the visual system may be affected, including the optic nerve and the retina. PD is mainly associated with motor dysfunction, but may also include visual deficits and retinal neurodegeneration. Glaucoma is a multifactorial neurodegenerative disease, characterized by the progressive loss of the axons of the retinal ganglion cells, leading to an increase optic disc excavation and a thinning of the neuroretinal ring, causing irreversible vision loss. In conclusion, neurodegenerative diseases present alterations in the retina as well as in the visual pathway and that, therefore, the eye can be used as an early neurodegeneration biomarker.