Effects of MS on the Visual Pathway Two Main High Priority Gaps to - - PowerPoint PPT Presentation

Smartphone Suite of Visual Tests in Multiple Sclerosis Randy Kardon MD PhD1,2

Kasra Zarei BS MS2, Pieter Pooman1,2 and Sabina David3, Claudia Christina Pfleger3, Dalia Berman4, and Johannes Ledolter PhD2

1Dept of Ophthalmology, University of Iowa, Iowa City, Iowa 2Iowa City VA Center for the Prevention and Treatment of Visual Loss 3Department of Neurology, Aalborg University Hospital 4Department of Ophthalmology, Aalborg University Hospital

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

ACTRIMS 2019

IMSVISUAL Symposium

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 Contrast Sensitivity Function

“vanishing”

• ptotypes

Major Elements of Visual Function

Critical Flicker Fusion Visual Acuity Contrast Sensitivity Contrast Sensitivity Function

vanishing

• ptotypes

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 Contrast Sensitivity Function

vanishing

• ptotypes

eyeAcuity Landolt C Ring

User must indicate the direction of the gap in the ring in a forced-choice task Good measure of visual acuity: the smallest size where the direction

• f the gap is

identified correctly 50% of the time

Developed by Michael Bach PhD, Freiberg

eyeAcuity Landolt C Ring

User must indicate the direction of the gap in the ring in a forced-choice task Good measure of visual acuity: the smallest size where the direction

• f the gap is

identified correctly 50% of the time

Major Elements of Visual Function

Critical Flicker Fusion Visual Acuity Contrast Sensitivity Contrast Sensitivity Function

vanishing

• ptotypes

eyeContrast Landolt C Ring

eyeContrast Landolt C Ring

Major Elements of Visual Function

Critical Flicker Fusion Visual Acuity Contrast Sensitivity Contrast Sensitivity Function

vanishing

• ptotypes

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

Smartphone

Vanishing Optotypes

spatial frequency contrast

Vanishing Optotypes If resolved, they are seen on a background, but if below threshold of perception, they “vanish”

spatial frequency contrast

Can vary both spatial frequency and contrast

Contrast Sensitivity Spatial Frequency cycles/degree Contrast Sensitivity Function Visual Acuity

In this example, your acuity is determined by where the tapering line vanishes

Vanishing Optotypes If resolved, they are seen on a background, but if below threshold of perception, they “vanish”

spatial frequency contrast

Can vary both spatial frequency and contrast

Contrast Sensitivity Spatial Frequency cycles/degree Contrast Sensitivity Function Visual Acuity

In this example, your acuity is determined by where the tapering line vanishes

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!