Biofeedback stimulation in the visually impaired: a systematic review of literature

Abstract

Background: It is estimated that approximately 1.3 billion people live with some form of distance or near visual impairment. Numerous studies have been carried out to evaluate the effects of biofeedback (BF) and establish if it could be a useful tool in vision rehabilitation for various eye diseases. Objective: This systematic review aimed: 1) to examine the current evidence of BF efficacy for the rehabilitation of the visually impaired and 2) to describe methodological variations used in previous BF studies to provide recommendations for vision rehabilitation interventions. Methods: A systematic review was conducted in the Medline, PubMed, Cochrane Library and Web of Science databases to collect documents published between January 2000 and May 2020. Of the 1,960 studies identified, 43 met the criteria for inclusion. The following information was collected from each study: sample size, control group, any eye disease, apparatus used, frequency and number of sessions of BF, main outcomes of training and whether a follow-up was conducted. The first group included studies published as scientific articles in peer-reviewed journals. The second group included abstracts of studies presented at peer-reviewed conferences. Publications were also grouped according to the eye disease treated. Results: 25 articles and 18 peer-reviewed conference abstracts (PRCAs) were included in this review. BF stimulation is a commonly used technique for the treatment of visual impairment caused by macular disease. Most BF studies evaluate the effect of training on the preferred retinal locus (PRL), particularly with regard to fixation location and stability. Across these studies, participants who received BF intervention improved fixation stability and reading speed. High variability in the number of sessions and the duration of BF training was found. Most studies did not use a control group. Conclusions: The findings of this review present evidence for biofeedback treatment in vision rehabilitation, with improved oculomotor abilities. Currently, it is not possible to formulate evidence-based recommendations for a standard training procedure due to the poor quality of existing randomised controlled trials. High-quality studies are needed to develop standard protocols for a range of eye diseases.

Vision Rehabilitation Using Microperimetric Biofeedback Training in Age- Related Macular Degeneration

“…observed different results; improvement in NVA and reading rate was not followed by BCVA. [12][13][17][18][19][20][21][22] Visual rehabilitation using MBFT has been found to improve retinal sensitivity in ve different macular diseases. When an area of the retina is damaged, the activity of cortical neurons there will remain active with stimulation from other parts of the retina.…”

“…As shown in this study's ndings, MBFT showed a promising result in improving reading speed. 17,19,22,30,31 In this study, six times of training with oneweek intervals and 10 minutes duration each session were carried out. With a total number of training exercises less than in other studies, it is hoped that this study can be used as a baseline for the standard given to patients with AMD.…”

Efficacy of MP-3 microperimeter biofeedback fixation training for low vision rehabilitation in patients with maculopathy

“…In the Western world, AMD is also the leading cause of irreversible loss of central vision in adults over 50 years old [ 3 , 4 ]. Low vision patients suffer significant loss of abilities such as locomotion, reading, driving, face recognition, and those related to social relationships [ 5 ]. No currently available treatment is effective in the reversal of geographic atrophy progression caused by macular lesions [ 6 ].…”

MAIA microperimeter for short‐duration fixation stability measurements in central vision loss: Repeatability and comparison with the Nidek MP1

“…For example, it has been shown that an improvement in fixation stability is associated with a better visual outcome after successful macular hole surgery 12 or after treatment with intravitreal ranibizumab injections for neovascular macular degeneration 13,14 . Biofeedback training has also been used successfully in low vision clinics to improve fixation stability and relocate the PRL to a more suitable location for reading (i.e., above or below the scotoma), with promising results for reading rehabilitation of patients with central vision loss 15–18 . Based on this evidence, it has been suggested that fixation stability should be included as an outcome measure after treatment or intervention in patients with central vision loss 19 .…”

“…13,14 Biofeedback training has also been used successfully in low vision clinics to improve fixation stability and relocate the PRL to a more suitable location for reading (i.e., above or below the scotoma), with promising results for reading rehabilitation of patients with central vision loss. [15][16][17][18] Based on this evidence, it has been suggested that fixation stability should be included as an outcome measure after treatment or intervention in patients with central vision loss. 19 Currently, in the US National Institutes of Health clinical trial registry there are 145 clinical trials involving microperimetry, 23 of which specifically declared fixation stability as an outcome measure.…”