Epidemiological and etiopathogenetic premises

Low vision is still a little known area of ophthalmology and requires constant study, a multifactorial approach, multiple skills and a two-way dialogue with the other sectors of the ophthalmological discipline. The lack of communication among experts hampers a higher level of cognition about this topic. This volume, in the philosophy of Low Vision Books, deals analytically with two fundamental aspects with which rehabilitation operators must measure themselves: neuro-enhancement and neuro-modulation. The claim that a patient affected by retinitis pigmentosa cannot improve his visual condition because "there is no cure”, or that a patient with maculopathy and central scotoma cannot wear glasses to see better because the damage is irre- versible by now, does not take into account the neuro-strengthening mechanisms available both at the retinal and cortical level, as well as along the nerve conduction pathways, in order to stabi- lize retinal functionality, fixations and the overall visual perception. The knowledge of the ocular, cerebral and vascular co-factors that are at the base of the vision and the strategies to have an adequate interaction among these components, helps the patient to improve the modalities with which the retinal im- age is captured and then transferred as electrical micro-impulses in order to be received and inter- preted at the cortical level. It is possible to boost visual perception by stimulating neurogenesis and improving blood flows, both at retinal and cerebral level. A patient with visual impairment can be tran- formed into one with a better sight, pleased with himself and the care received and more integrated with the society in which he lives. It is not just a question of applying an optical aid to enlarge a sequence of characters. The main goal is to have a neuro-enhancement of the resid- ual visual function, through medical, rehabilita- tion and surgical techniques. Namely, the purpose of this text is to analytically evaluate the various techniques able to mod- ulate the nervous system functions, to finally improve the perception of the signal. The neuro-modulation can be obtained using techniques that seem to be very different: neu- ro-micro-electric stimuli at retinal and / or ce- rebral level, pulsed stimulations obtainable with optical patterns at determined frequencies, flicker stimulations, microperimetric biofeedbacks. Complex systems can be carried out in special centers while simpler systems can be done in a domestic environment. Despite it has been little known until recently, neuro-modulation accounts for a tool that will revolutionize the concept of visual rehabilitation in the near future.