17
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      Innovative vision rehabilitation method for hemianopsia: Comparing pre- and post audio-luminous biofeedback training for ocular motility improving visual functions and quality of life

      research-article

      Read this article at

      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Background

          Homonymous hemianopsia (HH) corresponds to vision loss in one hemi-field secondary to retro-chiasmal injury. Patients with HH experience difficulties in scanning and orientation in their environment. Near vision daily activities such as reading can also be impaired. There is an unmet need for standardized vision rehabilitation protocols for HH. We investigated the effectiveness of biofeedback training (BT), used for vision rehabilitation in patients with central vision loss, in individuals with HH.

          Methods

          In this prospective pilot pre/post study, 12 participants, with HH consecutive to brain injury, performed 5 weekly BT sessions for 20 min each under supervision using the Macular Integrity Assessment microperimeter. BT consisted of relocation of the retinal locus 1–4° toward the blind hemi-field. Outcomes measured post-BT were paracentral retinal sensitivity, visual acuity (near vision), fixation stability, contrast sensitivity, reading speed, and visual functioning questionnaire. Statistical analysis was performed using Bayesian paired t-tests.

          Results

          Paracentral retinal sensitivity significantly increased by 2.7 ± 0.9 dB in the treated eye in 9/11 of the participants. Significant improvements with medium-to-large effect size were observed for fixation stability (8/12 participants), contrast sensitivity (6/12 participants) and near vision visual acuity (10/12 participants). Reading speed increased by 32.5 ± 32.4 words per minute in 10/11 participants. Quality of vision scores improved significantly with large effect size for visual ability, visual information and mobility.

          Conclusion

          BT led to encouraging improvements in visual functions and functional vision in individuals with HH. Further confirmation with larger trials is required.

          Related collections

          Most cited references29

          • Record: found
          • Abstract: found
          • Article: not found

          Psychophysics of reading--XVI. The visual span in normal and low vision.

          The visual span in reading is the number of characters that can be recognized at a glance. The shrinking visual span hypothesis attributes reading deficits in low vision, and slow reading in normal vision at low contrast, to a reduction in the visual span. This hypothesis predicts that reading time (msec/word) becomes increasingly dependent on word length as text contrast decreases. We tested and confirmed this prediction using the rapid serial visual presentation (RSVP) method. Estimates of the visual span ranged from about 10 characters for high-contrast text to less than two characters for low-contrast text. Eye-movement recordings showed that longer reading times at low contrast are partitioned about equally between prolonged fixation times and an increased number of saccades (presumably related to a reduced visual span). RSVP measurements for six out of seven low-vision subjects revealed a strong dependence of reading time on word length, as expected from reduced visual spans.
            Bookmark
            • Record: found
            • Abstract: found
            • Article: found
            Is Open Access

            Homonymous hemianopia: challenges and solutions

            Stroke is the most common cause of homonymous hemianopia (HH) in adults, followed by trauma and tumors. Associated signs and symptoms, as well as visual field characteristics such as location and congruity, can help determine the location of the causative brain lesion. HH can have a significant effect on quality of life, including problems with driving, reading, or navigation. This can result in decreased independence, inability to enjoy leisure activities, and injuries. Understanding these restrictions, as well as the management options, can aid in making the best use of remaining vision. Treatment options include prismatic correction to expand the remaining visual field, compensatory training to improve visual search abilities, and vision restoration therapy to improve the vision itself. Spontaneous recovery can occur within the first months. However, because spontaneous recovery does not always occur, methods of reducing visual disability play an important role in the rehabilitation of patients with HH.
              Bookmark
              • Record: found
              • Abstract: found
              • Article: found
              Is Open Access

              Asymmetries in visual acuity around the visual field

              Human vision is heterogeneous around the visual field. At a fixed eccentricity, performance is better along the horizontal than the vertical meridian and along the lower than the upper vertical meridian. These asymmetric patterns, termed performance fields, have been found in numerous visual tasks, including those mediated by contrast sensitivity and spatial resolution. However, it is unknown whether spatial resolution asymmetries are confined to the cardinal meridians or whether and how far they extend into the upper and lower hemifields. Here, we measured visual acuity at isoeccentric peripheral locations (10 deg eccentricity), every 15° of polar angle. On each trial, observers judged the orientation (± 45°) of one of four equidistant, suprathreshold grating stimuli varying in spatial frequency (SF). On each block, we measured performance as a function of stimulus SF at 4 of 24 isoeccentric locations. We estimated the 75%-correct SF threshold, SF cutoff point (i.e., chance-level), and slope of the psychometric function for each location. We found higher SF estimates (i.e., better acuity) for the horizontal than the vertical meridian and for the lower than the upper vertical meridian. These asymmetries were most pronounced at the cardinal meridians and decreased gradually as the angular distance from the vertical meridian increased. This gradual change in acuity with polar angle reflected a shift of the psychometric function without changes in slope. The same pattern was found under binocular and monocular viewing conditions. These findings advance our understanding of visual processing around the visual field and help constrain models of visual perception.
                Bookmark

                Author and article information

                Contributors
                Journal
                Front Neurol
                Front Neurol
                Front. Neurol.
                Frontiers in Neurology
                Frontiers Media S.A.
                1664-2295
                11 April 2023
                2023
                : 14
                : 1151736
                Affiliations
                [1] 1Toronto Western Hospital, University Health Network , Toronto, ON, Canada
                [2] 2Department of Ophthalmology and Vision Science, Faculty of Medicine, University of Toronto , Toronto, ON, Canada
                [3] 3Department of Occupational Science and Occupational Therapy, University of Toronto , Toronto, ON, Canada
                [4] 4Donald K. Johnson Eye Institute, Krembil Research Institute, University Health Network , Toronto, ON, Canada
                Author notes

                Edited by: Pawel Kiper, San Camillo IRCCS S.r.l. Società Unipersonale, Italy

                Reviewed by: Stefan Hawelka, University of Salzburg, Austria; Michael Christian Leitner, University of Applied Sciences Salzburg, Austria

                *Correspondence: Monica Daibert-Nido, monica.nido@ 123456uhn.ca

                These authors share senior authorship

                This article was submitted to Neurorehabilitation, a section of the journal Frontiers in Neurology

                Article
                10.3389/fneur.2023.1151736
                10126773
                37114220
                6ce951bf-6b00-4fd7-b367-3ed4e2dbd9b0
                Copyright © 2023 Misawa, Pyatova, Sen, Markowitz, Markowitz, Reber and Daibert-Nido.

                This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

                History
                : 26 January 2023
                : 22 March 2023
                Page count
                Figures: 4, Tables: 2, Equations: 0, References: 29, Pages: 7, Words: 4859
                Categories
                Neurology
                Original Research

                Neurology
                biofeedback training - bt,hemianopia or hemianopsia,rehabilitation,vision,visual fields,microperimetry sensitivity,fixation stability,quality of life

                Comments

                Comment on this article