CRISTINA DANCA, CLAUDIA FLORIDA COSTEA,VICTOR VLAD COSTAN, MIHAELA DANA TURLIUC, ANCA SAVA, SERBAN TURLIUC, ANDREI CUCU, RALUCA ALINA DRAGOMIR, IOANA SADIYE SCRIPCARIU, NICOLETA DUMITRESCU, ALEXANDRU CARAULEANU GUT MICROBIOTA AND SEROTONIN - BIOCHEMICAL PATHWAYS IN AGE-RELATED MACULAR DISEASE Age-related macular degeneration (AMD) is a multifactorial disease and is a major cause of blindness in the entire world. Current studies show a tight connection between gut microbiota and AMD. This literature review shows the positive role played by gut microbiota, which is essential in providing the optimal serotonin level in retina protection against the noxious action of various factors of the environment. Serotonin or 5-hydroxytryptamine (5-HT) is a monoamine neurotransmitter derived from tryptophan which is poorly expressed in the retina, but it may provide protection against retinal damage, such as light-induced retinopathy and age-related macular degeneration, due to the fact that certain serotonin receptor agonists and antagonists of those 7 classes and 17 subtypes of 5-HT receptors help prevent serum deprivation, anoxia and oxidative damage. Our study also shows the role played by other diet-related factors, which protect retina against oxidative stress and delay the onset of AMD.