Biofeedback rehabilitation in ophthalmology

The biofeedback techniques used to treat patients have been around for over a quarter of a century, and the procedures themselves for over half a century. The term "biofeedback" was coined in late 1969 to describe laboratory procedures (developed in the 1940's) that trained research subjects to alter brain activity, blood pressure, muscle tension, heart rate and other bodily functions that are not normally controlled voluntarily. Although most people initially viewed these practices with skepticism, researchers proved that many individuals could alter their involuntary responses by "feeding back" information either visually or audibly to show what was occurring in their bodies. Today, research has demonstrated that biofeedback can help in the treatment of many diseases and painful conditions. BF techniques applied to vision are still being studied for both their methodological and physiological aspects. Giorgi, Contestabile, and Vingolo et al. have proposed different visual rehabilitation techniques and instruments using biofeedback strategies starting from basic systems like an Accomotrack Vision Trainer (which is a high- speed infrared optometer which records the vergence of light reflected from the retina at a rate of 40 Hz, then converts the signal into an auditory tone which increases in pitch and rate as accommodation decreases; the subject listens to the tone and thus receives immediate auditory feedback as to his/ her accommodative status) or improved biofeedback integrated system (IBIS) devices, merging to more complex instruments as the fundus related MP-1 microperimeter (Nidek Technologies, Padua, Italy). Recently introduced techniques, such as microperimetry by a scanning laser ophthalmoscope (SLO), microperimetry together with the ongoing research targeting the neurophysiology, and neuro-modelling lead us to a better knowledge of the cognitive processes of rehabilitation and can also serve as a useful diagnostic as well as a therapeutic tool for the treatment of retinal disease. Visual training with visually evoked assisted biofeedback has been used to improve performance in high speed drivers and precision shooters. Computer programs for visual stimulation have been used to treat amblyopia, offering to shift the visual training into the domestic sphere. Several randomized control studies on vision training systems, consisting of a background stimulation by a drifting sinusoidal grating, combined with a foreground game aimed at maintaining attention have been reported in this field. Furthermore, visual training has also been used to improve the saccadic performance in dyslexic children with deficitary eye movement control. This indicates that daily practice improved not only perceptual capacity, but also voluntary saccade control within 3 to 8 weeks. After training, the group of dyslexics was no longer statistically different from the control group. This chapter aims to review the history, methodology and application of biofeedback techniques to vision. © 2012 by Nova Science Publishers, Inc. All rights reserved.