![]() 22 In addition, good arguments can be made that outcomes assessments need to go a step further to incorporate patient reported outcomes and quality of life measures. Some aspect of functional ability should be considered, and is recognized in the field of low vision. 4, 18– 21 At the present time, there is no agreement among researchers working in these nascent fields regarding the most appropriate outcomes tools. 2011 52:ARVO E-Abstract 109 Nau A, et al. Moreover, if such outcomes can be standardized, comparisons between different types of artificial vision devices would be facilitated 17 ( Several studies have used various techniques such as light detection, square pointing, object recognition, mobility tasks, and resolution as ways to show improvement over baseline for patients using artificial vision (Friberg TNA, et al. Establishing objective methods to determine improvement in function is vital to gauge performance improvement, to compare subsequent device iterations, and for regulatory approval. 9, 15, 16 Because current artificial vision technology cannot recapitulate the complexity of normal vision, traditional clinical methods of assessing visual function are not appropriate. Presently, the resolution of artificial vision and sensory substitution devices provide what is termed “ultra-low vision,” allowing for crude perceptions of larger, high contrast objects. 10– 14 While there is some evidence that sensory substitution might be a viable method to improve appreciation of the environment among the blind, there are no studies that attempt to systematically evaluate outcomes measures for this modality of “vision” restoration. 9, 10 In addition, our work, as well as that of others, shows that the visual cortex is activated by sensory substitution. With rehabilitation and appropriate training, the brain can learn to translate this input into visual qualia. 5– 8 Sensory substitution devices exploit input from the remaining intact auditory or tactile senses, and may be an option for patients who no longer have eyes or functional ocular components. 2– 4 Sensory substitution devices aim to circumvent primary visual pathways and try to provide visual information through nonvisual, afferent circuits. 1 The retinal implant is currently the frontrunner of artificial vision technology, though its use is limited to those with functioning optic nerves. This study is one of many that will need to be undertaken to achieve a common outcomes infrastructure for the field of artificial vision.īlindness is a severe disability affecting over 36 million people worldwide, including 694,000 in the United States. Tactile-based sensory substitution devices are amenable to psychophysical assessments of vision, even though traditional visual pathways are circumvented. Motion tests were limited by BrainPort resolution. Increases were statistically significant for tests of light perception (8.27 ± 3.95 SE), time resolution (61.4% ± 3.14 SE), light localization (44.57% ± 3.58 SE), grating orientation (70.27% ± 4.64 SE), and white Tumbling E on a black background (2.49 logMAR ± 0.39 SE). ![]() Mean success scores increased for all of our tests except contrast sensitivity. Most tests could be used with the BrainPort. Assessments were performed at baseline and again using the BrainPort after 15 hours of training. All subjects performed 11 computer-based psychophysical tests from three programs: Basic Assessment of Light Motion, Basic Assessment of Grating Acuity, and the Freiburg Vision Test as well as a modified Tangent Screen. Our control group consisted of six subjects ( n = 3 males, n = 3 females, average age 43) with healthy ocular status. Our blind group included 24 subjects ( n = 16 males and n = 8 females, average age 50) with light perception or worse vision. We enrolled 30 adult subjects (age range 22–74) divided into two groups. The BrainPort is a vision assist device coupling a live video feed with an electrotactile tongue display, allowing a user to gain information about their surroundings. We evaluated whether existing ultra-low vision tests are suitable for measuring outcomes using sensory substitution. ![]()
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