Topical Review: Assessment of Binocular Sensory Processes in Low Vision.

Significance: This article summarizes the evidence for a higher prevalence of binocular vision dysfunctions in individuals with vision impairment. Assessment for and identification of binocular vision dysfunctions can detect individuals experiencing difficulties in activities including reading, object placement tasks, and mobility.Comprehensive vision assessment in low vision populations is necessary to identify the extent of remaining vision and to enable directed rehabilitation efforts. In patients with vision impairment, little attention is typically paid to assessments of binocular vision, including ocular vergence, stereopsis, and binocular summation characteristics. In addition, binocular measurements of threshold automated visual fields are not routinely performed in clinical practice, leading to an incomplete understanding of individuals' binocular visual field and may affect rehabilitation outcomes.First, this review summarizes the prevalence of dysfunctions in ocular vergence, stereopsis, and binocular summation characteristics across a variety of ocular pathologies causing vision impairment. Second, this review examines the links between clinical measurements of binocular visual functions and outcome measures including quality of life and performance in functional tasks. There is an increased prevalence of dysfunctions in ocular alignment, stereopsis, and binocular summation across low vision cohorts compared with those with normal vision. The identification of binocular vision dysfunctions during routine low vision assessments is especially important in patients experiencing difficulties in activities of daily living, including but not limited to reading, object placement tasks, and mobility. However, further research is required to determine whether addressing the identified deficits in binocular vision in low vision rehabilitative efforts directly impacts patient outcomes.
Competing Interests: Conflict of Interest Disclosure: JT, MK, and AL receive salary support from Guide Dogs New South Wales/Australian Capital Territory, and JM is an employee of Guide Dogs New South Wales/Australian Capital Territory. JH and VK are recipients of Australian Government Research Training Program scholarships and PhD scholarships provided by Guide Dogs New South Wales/Australian Capital Territory. Guide Dogs New South Wales/Australian Capital Territory played no role in the conceptualization of this article, and the authors have no proprietary interest in any of the materials mentioned in this article.
(Copyright © 2021 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Optometry.)