DigiVis: Self-testing Vision App for Telephone Consultations

February 23, 2024 updated by: Louise Allen, Cambridge University Hospitals NHS Foundation Trust

DigiVis: Validation of Self-testing Visual Acuity Web-based App to Aid Ophthalmic Telephone Consultations During Covid19 Lockdown and Subsequent Social Distancing Crisis

This trial aims to assess the accuracy and test-retest variability of a new digital app which enables community visual acuity testing without requirement of an trained examiner.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

Eye problems like macular degeneration and amblyopia (lazy eye) require regular monitoring to prevent permanent visual impairment. Over 2000 patients a month are seen in Cambridge University Hospitals National Health Service Trust (CUH) eye clinics; concern about Covid-19 infection has led to over 80% of consultations being conducted by telephone with few clinical clues to inform decision making. Patients will face long delays even when routine clinics restart: there is no doubt that some will suffer preventable visual loss.

DigiVis is a web-based vision testing app enabling self-testing of vision at home. Early testing and patient feedback is positive: 80% of children prefer DigiVis to regular testing. The investigators wish to test how accurately the app works for home use, by asking older children and adults to self-test their vision prior to their planned face to face clinic appointment. Once tested, DigiVis will be available free of charge to patients, not only during the Covid-19 crisis, but also to support telephonic consultations in the future.

Visual acuity (VA) is a fundamental measure of vision required for all ophthalmic assessments. It is measured by health professionals using vision charts. DigiVis is a new app which enables self-testing of VA using two wirelessly connected digital devices. By matching letters on a handheld device to those displayed on the second device a distance away, threshold VA can be measured using a staircase algorithm. The distance and scaling of the test is vital to its accuracy and a concept (patent filed by Cambridge Enterprise) in DigiVis enables this without the need for manual distance measurement or an observer.

Early validation using two tablet computers in 150 clinic patients has given positive results, both in testing accuracy and patient feedback. With the current Covid-19 crisis limiting face to face appointments, there is an urgent need for accurate home VA assessment. The DigiVis app has been re-coded for free website delivery for this purpose.

The investigators wish to formally validate DigiVis home testing following Conformitè Europëenne (CE class I) marking so that it can be recommended for clinical use. 250 patients will be invited to self-test their VA twice using DigiVis prior to a planned face to face clinic appointment. The test-retest variability and comparison of DigiVis VA to chart based assessment will be compared.

Study Type

Interventional

Enrollment (Actual)

120

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United Kingdom
    • Cambs
      • Cambridge, Cambs, United Kingdom, CB2 0QQ
        • Cambridge University Hospitals NHS Trust

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

5 years to 85 years (Child, Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Age between 5 and 85 years
  • Previous recorded visual acuity of at least +0.8 logMAR in or both eyes

Exclusion Criteria:

  • Individuals with poor conversant English
  • Individuals with cognitive impairment
  • Subjects unable to access the internet on two digital devices

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Screening
  • Allocation: N/A
  • Interventional Model: Sequential Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Other: Subjects recruited to visual acuity testing
All recruited subjects will have the intervention (Digivis visual acuity self-testing) and the standard clinical visual acuity assessment in clinic.
Device: DigiVis visual acuity app
Self-testing of visual acuity app on two occasions

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Mean Bias Between the Difference Between DigiVis and Standard Visual Assessment Compared to the Mean of DigiVis and Standard Visual Assessment
Time Frame: within 30 days
The mean bias (difference) in visual acuity assessment score between the difference in DigiVis and standard testing in logMAR units and the mean of DigiVis and standard testing in logMAR units was calculated. Where 0.00 logMAR is the value representing perfect distance visual acuity (equivalent to 20/20 Snellen acuity) and 1.00 logMAR is the value representing worst distance visual acuity (equivalent to 20/200 Snellen acuity).
within 30 days

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Mean Bias Between Repeated DigiVis Test Assessments
Time Frame: within 30 days
Mean bias between the difference of two DigiVis visual acuity assessments compared to the mean of two digiVis assessments measured in logMAR units.
within 30 days

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Cambridge University Hospitals NHS Foundation Trust

Investigators

  • Study Director: Stephen E Kelleher, Cambridge University Hospitals NHS Foundation Trust

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

July 24, 2020

Primary Completion (Actual)

August 1, 2021

Study Completion (Actual)

August 1, 2021

Study Registration Dates

First Submitted

July 17, 2020

First Submitted That Met QC Criteria

July 21, 2020

First Posted (Actual)

July 22, 2020

Study Record Updates

Last Update Posted (Actual)

August 5, 2024

Last Update Submitted That Met QC Criteria

February 23, 2024

Last Verified

February 1, 2024

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • IRAS196573

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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