Smartphone Suite of Visual Tests in Multiple Sclerosis Randy Kardon MD PhD 1,2 Kasra Zarei BS MS 2 , Pieter Pooman 1 , 2 and Sabina David 3 , Claudia Christina Pfleger 3 , Dalia Berman 4 , and Johannes Ledolter PhD 2 1 Dept of Ophthalmology, University of Iowa, Iowa City, Iowa 2 Iowa City VA Center for the Prevention and Treatment of Visual Loss 3 Department of Neurology, Aalborg University Hospital 4 Department of Ophthalmology, Aalborg University Hospital
ACTRIMS 2019 IMSVISUAL Symposium FINANCIAL DISCLOSURE I have the following financial interests or relationships to disclose: • Funding from NEI R009040554; R01 EY018853 • Funding from Department of Defense; TATRC • Funding from VA Rehabilitation Research and Development • Novartis steering committee OCTiMS • Co-founder of MedFace™ and FaceX ™ which use facial features to assess light sensitivity, vision and neurological functions
Effects of MS on the Visual Pathway Two Main High Priority Gaps to Fill: • Need for early detection of visual pathway disturbances after acute clinical and subclinical MS activity • Need to monitor changes in the visual pathway over time in MS patients and capture variations due to changes in nerve conduction How Can We Accomplish This?
Planet of the Apps • Use of smartphone technology and mobile devices are emerging in health care settings – Provide wider accessibility for testing – Opportunity to increase time sampling may facilitate clinical decision making • Most are used sparingly in vision testing and not yet widely adopted – why? – Lack of calibration and validation
What Makes A Smartphone Test Viable? • The visual output of the device must match the intended input in terms of multiple parameters (technical validation) • Parameters for vision tests: • Brightness • Luminance • Spatial resolution • Temporal resolution • Confounding variables (ambient lighting, viewing distance) • Clinical validation
Implementation of Smartphone Tests • 4 tests developed – Critical flicker fusion (visual conduction speed) – Landolt C visual acuity – Contrast sensitivity at fixed spatial frequency – Contrast sensitivity at different spatial frequencies • Primarily developed for iOS platform
Major Elements of Visual Function Critical Flicker Fusion Visual Acuity Contrast Sensitivity Function Contrast Sensitivity “vanishing” optotypes
Major Elements of Visual Function Critical Flicker Fusion Visual Acuity Contrast Sensitivity Function Contrast Sensitivity vanishing optotypes
eyeFusion Critical Flicker Fusion • A measure of visual conduction time • Can vary frequency at fixed contrast • Can vary contrast at fixed frequency
Major Elements of Visual Function Critical Flicker Fusion Visual Acuity Contrast Sensitivity Function Contrast Sensitivity vanishing optotypes
eyeAcuity User must indicate the direction of the gap in the ring in a forced-choice task Landolt C Ring Good measure of visual acuity: the smallest size where the direction of the gap is identified correctly 50% of the time Developed by Michael Bach PhD, Freiberg
eyeAcuity User must indicate the direction of the gap in the ring in a forced-choice task Landolt C Ring Good measure of visual acuity: the smallest size where the direction of the gap is identified correctly 50% of the time
Major Elements of Visual Function Critical Flicker Fusion Visual Acuity Contrast Sensitivity Function Contrast Sensitivity vanishing optotypes
eyeContrast Landolt C Ring
eyeContrast Landolt C Ring
Major Elements of Visual Function Critical Flicker Fusion Visual Acuity Contrast Sensitivity Function Contrast Sensitivity vanishing optotypes
Smartphone Vanishing Optotypes A vanishing optotype is a line drawing of an object on a smooth, diffuse grayscale background By altering the line properties used to define the shape of the vanishing optotype, one can vary its spatial frequency independent of target size spatial frequency contrast
Can vary both spatial Vanishing Optotypes frequency and contrast spatial frequency If resolved, they are seen on a background, but if below threshold of contrast perception, they “vanish” Contrast Sensitivity Function Contrast Sensitivity Visual Acuity In this example, your acuity is determined by where the Spatial Frequency tapering line vanishes cycles/degree
Can vary both spatial Vanishing Optotypes frequency and contrast spatial frequency If resolved, they are seen on a background, but if below threshold of contrast perception, they “vanish” Contrast Sensitivity Function Contrast Sensitivity Visual Acuity In this example, your acuity is determined by where the Spatial Frequency tapering line vanishes cycles/degree
Pilot Study – Aalborg University MS Clinic 104 age-matched control subjects and 117 MS patients; 74 with no history of optic neuritis, 43 with prior optic neuritis • Landolt C smartphone visual acuity • Landolt C smartphone contrast sensitivity • Critical flicker fusion contrast threshold at 7.5, 15 and 30 Hz • Near 2.5% contrast acuity card test • Distant EDTRS acuity test • Topcon Maestro OCT of RNFL and GCL thickness
Pilot Study – Aalborg University MS Clinic N=normal control subjects MS-ON= no prior optic neuritis MS+ON= prior optic neuritis
Pilot Study – Normal Subjects by Age
Summary • A battery of smartphone tests have been developed • Technical validation of temporal frequency and contrast parameters has been accomplished • Preliminary investigations completed for determining – Test-retest reliability – Blurring effects studied using Bangerter diffusion foils – Binocular summation effects – Quantification of normative ranges (and abnormal subject data) • Pilot study results in MS patients looks promising
Benefits of Smartphone Testing in MS • Visual dysfunction can be detected leading to earlier interventions • Can study the time-scale of disease and monitor treatment at home • Reduce the effects of anxiety on functional performance by home testing • Low cost – saving of health care dollars • Large-scale, rapid recruitment of subjects and data collection • Genotype-phenotype correlations • Can be made widely accessible with easy distribution • Regulatory pathway to home-use with HIPAA compliant database, enabling reporting to patient and healthcare personnel
On the Horizon Automated pupil, ocular motility, eyelid and facial feature assessment from accessory to smartphone or tablet
On the Horizon Automated pupil, ocular motility, eyelid and facial feature assessment from accessory to smartphone or tablet
On the Horizon Automated pupil, ocular motility, eyelid and facial feature assessment from accessory to smartphone or tablet
Thank You!
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