Contour Enhancement Benefits Older Adults with Simulated Central Field Loss

Abstract

Purpose Age-related macular degeneration (AMD) is the leading cause of vision loss among Americans over the age of 65. Currently, no effective treatment can reverse the central vision loss associated with most AMD. Digital image-processing techniques have been developed to improve image visibility for peripheral vision; however, both the selection and efficacy of such methods are limited. Progress has been difficult for two reasons: the exact nature of image enhancement that might benefit peripheral vision is not well understood, and efficient methods for testing such techniques have been elusive. The current study aims to develop both an effective image-enhancement technique for peripheral vision and an efficient means for validating the technique. Methods We used a novel contour detection algorithm to locate shape-defining edges in images based on natural-image statistics. We then enhanced the scene by locally boosting the luminance contrast along such contours. Using a gaze-contingent display, we simulated central visual field loss in normally-sighted young (ages 18–30) and older adults (ages 58–88). Visual search performance was measured as a function of contour enhancement strength ("Original" (unenhanced), "Medium", and "High"). For preference task, a separate group of subjects judged which image in a pair "would lead to better search performance". Results We found that while contour enhancement had no significant effect on search time and accuracy in young adults, Medium enhancement resulted in significantly shorter search time in older adults (~13% reduction relative to Original). Both age groups preferred images with Medium enhancement over Original (2 to 7 times). Furthermore, across age groups, image content types and enhancement strengths, there was a robust correlation between preference and performance. Conclusions Our findings demonstrate a beneficial role of contour enhancement in peripheral vision for older adults. Our findings further suggest that task-specific preference judgments can be an efficient surrogate for performance testing.

Evaluation of a gaze-controlled vision enhancement system for reading in visually impaired people

“…And even more sophisticated enhancements might be added. For instance, digital filtering tailored to low vision constraints might be applied within the ROAV [81]. Some low-level visual modifications could easily be implemented within the ROAV with the goal of reducing crowding [82].…”

Comparing object recognition from binary and bipolar edge features

“…Such enhancements have been implemented for video displays [15–17]. Both binary edges and bipolar edges have been employed in such studies.…”

An Augmented-Reality Edge Enhancement Application for Google Glass

“…Increased edge-contrast has been demonstrated to be preferred by patients with AMD and other low vision conditions when watching TV 12, 16, 45 or viewing images 15, 17 . Edge enhancement has also been demonstrated to improve performance in a search tasks performed on a computer screen.…”

“…Edge enhancement has also been demonstrated to improve performance in a search tasks performed on a computer screen. 15–17, 45 The utility of this approach for enhancing the natural environment has been suggested, but so far has not been implemented due to technological limitations. The Google Glass appears to overcome many of these limitations and thus may provide a valuable platform for implementing a variety of applications that can aid patients with various low vision conditions: 1) at a very reasonable cost, 2) with a cosmetically acceptable and socially desirable format, and 3) with flexibility that supports further innovation.…”

“…13, 14 Using desktop displays, it has been shown that adding high contrast edges to static images, 15 or videos 16 is preferred by patients with AMD, 15, 16 and improved visual search performance of elderly with simulated central visual loss. 15, 17 …”