Evaluation of a Virtual Bioptic Telescope and Virtual Projection - - PowerPoint PPT Presentation

Evaluation of a Virtual Bioptic Telescope and Virtual Projection Screen for Low Vision Patients

ASHLEY DEEMER, OD

WILMER EYE INSTITUTE JOHNS HOPKINS SCHOOL OF MEDICINE

Disclosures

I have no financial disclosures Visionize, LLC was involved in providing equipment for the study

Purpose

§Magnification is used to compensate for reduced visual acuity §Using a head-mounted display equipped with a high- resolution video camera, we can employ virtual reality methods to magnify images in real time §Existing head-mounted display units magnify the entire view and with high levels of magnification, image movement becomes problematic §Here we test a virtual bioptic telescope and virtual projection screen as an innovative approach to magnification

Iris Vision

Virtual Bioptic

Virtual Projection Screen

Home Trial

• Observational study – aimed to determine if these

approaches to magnification are beneficial to low vision patients performing ADLs

• 30 participants were recruited from the Low Vision Center

at the Wilmer Eye Institute

• 13 female, 17 male
• Mean age 53 years old, Age range 19-93
• BCVA <20/100 in the better-seeing eye
• Acuity ranged from 20/100 to 20/400
• Bilateral central scotomas with normal peripheral VF

Home Trial

• All participants had prior exposure to low vision services

and were experienced visual assistive equipment users

• The participants had basic operational training for 30-45

min in clinic

• Then took the system home for a 7-10 day trial

Outcome Measures

• The Activity Inventory (AI) was administered before and

after the home-trial to measure effect on self-reported visual function

• Simulator sickness questionnaire and system-use survey

were administered twice by telephone during the trial period

• Baseline and follow-up AI results were analyzed using a

Rasch model

Results – Effect Size

• 0.2

0.2 0.4 0.6 0.8 1 1.2 1.4 Goals Reading Mobility Vis Info Vis Motor Outside Home Inside Home Effect Size Visual Abiliity Domain

Results – Minimal Clinically Important Difference (MCID)

Domain MCID frequency % of participants Goals 69.0% Visual Info 86.2% Reading 85.7% Outside Home 78.6% Inside Home 72.4% Mobility 45.5% Visual Motor 44.0%

Simulator Sickness Questionnaire

Simulator Sickness Questionnaire

• 5 patients (17%) reported headache
• 4 patients (13%) reported symptoms of nausea
• 11 patients (38%) reported experiencing eye strain
• 7 patients (24%) “barely”
• 2 patients (7%) “moderately”
• 2 patients (7%) “very”

System-Use Survey

• Each participant was asked “How useful did you find the device?”
• The average ordinal patient rating was 7.14/10
• 17 (57%) of the patients said they would be interested in purchasing the

device for their personal use

Conclusions

• The use of this virtual bioptic system / virtual projection screen resulted

in improvements in visual function in the following domains:

• Visual Information
• Reading
• Outside the home tasks
• Inside the home tasks
• Goals
• The system was not effective for improving mobility and visual motor

function

Conclusions

• Overall, this group of experienced visual assistive device users found

this method of magnification to be effective in their daily activities

• Over half of the participants found the device to be useful enough to

consider purchasing

• A small, but significant number of participants reported symptoms of

discomfort while using the device

Thank you

Collaborators: Bob Massof James Deremeik Chris Bradley Kyoko Fujiwara Frank Werblin Nicole Ross Danielle Natale Visionize, LLC Reader’s Digest Partners for Sight Foundation Grant

Contact Information: Ashley Deemer adeemer1@jhmi.edu