Chancellery Research - Research Publications

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    Increased Depth, Reduced Extent, and Sharpened Edges of Visual Field Defects Measured by Compass Fundus Perimeter Compared to Humphrey Field Analyzer
    Liu, P ; Nguyen, BN ; Turpin, A ; McKendrick, AM (ASSOC RESEARCH VISION OPHTHALMOLOGY INC, 2021-10-01)
    Purpose: The purpose of this study was to compare visual field results of the COMPASS fundus perimeter (CMP) and the Humphrey Field Analyzer (HFA) in the same eyes; to compare structure-function concordance between circumpapillary retinal nerve fiber layer (Cp-RNFL) profiles and the two perimetry results; and to evaluate whether differences between the two results reflect postulated advantages of real-time eye movement compensation during perimetry. Methods: We retrospectively analyzed 24-2 visual field data measured with CMP and HFA together with Cp-RNFL optical coherence tomography (OCT) scan data from 95 eyes of 65 people with glaucoma. We defined visual field locations with total deviation (TD) less than -5 dB as defective. The CMP and HFA fields were compared on measures of: spatial extent (number of defective locations); depth (TD values); and sharpness of scotomata edges (maximum TD difference between defective locations and their neighbors). Structure-function concordance between Cp-RNFL profile and respective visual field was also compared. Results: Compared to the HFA, scotomata measured by CMP were of reduced spatial extent (mean difference = -3.14 locations, p < 0.001), greater depth (median TD of CMP = -17 dB versus HFA = -13 dB, p = 0.029) and steeper edges (median of maximum TD difference of CMP = 10.6 dB versus HFA = 6 dB, p < 0.001). Structure-function concordance between Cp-RNFL profile and either visual field were comparable despite the reduced scotoma spatial extent measured by CMP. Conclusions: Glaucomatous visual fields measured by CMP displayed characteristics consistent with expected effects of using real-time eye movement compensation technology compared to the widely used HFA. Translational Relevance: Glaucomatous visual field defects measured by the CMP are more localized, deeper, and steeper than those of the HFA.
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    A Depth-Dependent Integrated VF Simulation for Analysis and Visualization of Glaucomatous VF Defects
    Liu, P ; Mckendrick, AM ; Ma-Wyatt, A ; Turpin, A (ASSOC RESEARCH VISION OPHTHALMOLOGY INC, 2020-02-01)
    Purpose: Visual fields (VF) are measured monocularly at a single depth, yet real-life activities require people to interact with objects binocularly at multiple depths. To better characterize visual functioning in clinical vision conditions such as glaucoma, analyzing visual impairment in a depth-dependent fashion is required. We developed a depth-dependent integrated VF (DD-IVF) simulation and demonstrated its usefulness by evaluating DD-IVF defects associated with 12 glaucomatous archetypes of 24-2 VF. Methods: The 12 archetypes included typical variants of superior and inferior nasal steps, arcuate and altitudinal defects, temporal wedge, biarcuate, and intact VFs. DD-IVF simulation maps the monocular 24-2 VF archetypes to binocular ones as a function of depth by incorporating three parameters of fixation, object, and interpupillary distances. At each location and depth plane, sensitivities are linearly interpolated from corresponding locations in monocular VF and returned as the higher value of the two. Results: The simulation produced 144 DD-IVFs for multiple depths from combinations of 12 glaucomatous archetypes. The DD-IVFs are included as a Shiny app in the binovisualfields package. The number of impaired locations in the DD-IVFs varied according to the overlap of VF loss between eyes. Conclusions: Our DD-IVF program revealed binocular functional visual defects associated with glaucomatous archetypes of the 24-2 pattern and is designed to do the same for empirically measured VFs. The comparison of identified visual impairments across depths may be informative for future empirical exploration of functional visual impairments in depth in glaucoma and other conditions leading to bilateral VF loss. Translational Relevance: Our DD-IVF program can reveal depth-dependent functional visual defects for clinical vision conditions where 24-2 test patterns are available.
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    Robot Assistants for Perimetry: A Study of Patient Experience and Performance
    McKendrick, AM ; Zeman, A ; Liu, P ; Aktepe, D ; Aden, I ; Bhagat, D ; Do, K ; Nguyen, HD ; Turpin, A (ASSOC RESEARCH VISION OPHTHALMOLOGY INC, 2019-06-01)
    PURPOSE: People enjoy supervision during visual field assessment, although resource demands often make this difficult. We evaluated outcomes and subjective experience of methods of receiving feedback during perimetry, with specific goals to compare a humanoid robot to a computerized voice in participants with minimal prior perimetric experience. Human feedback and no feedback also were compared. METHODS: Twenty-two younger (aged 21-31 years) and 18 older (aged 52-76 years) adults participated. Visual field tests were conducted using an Octopus 900, controlled with the Open Perimetry Interface. Participants underwent four tests with the following feedback conditions: (1) human, (2) humanoid robot, (3) computer speaker, and (4) no feedback, in random order. Feedback rules for the speaker and robot were identical, with the difference being a social interaction with the robot before the test. Quantitative perimetric performance compared mean sensitivity (dB), fixation losses, and false-positives. Subjective experience was collected via survey. RESULTS: There was no significant effect of feedback type on the quantitative measures. For younger adults, the human and robot were preferred to the computer speaker (P < 0.01). For older adults, the experience rating was similar for the speaker and robot. No feedback was the least preferred option of 77% younger and 50% older adults. CONCLUSIONS: During perimetry, a social robot was preferred to a computer speaker providing the same feedback, despite the robot not being visible during the test. Making visual field testing more enjoyable for patients and operators may improve compliance and attitude to perimetry, leading to improved clinical outcomes. TRANSLATIONAL RELEVANCE: Our data suggest that humanoid robots can replace some aspects of human interaction during perimetry and are preferable to receiving no human feedback.