DigiVis: Self-testing Vision App for Telephone Consultations

Visual Impairment Clinical Trial

Official title:

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

Clinical Trial Details — Status: Recruiting

Administrative data

• NCT number: NCT04482387
• Other study ID #: IRAS196573
• Status: Recruiting
• Phase: N/A
• Start date: July 24, 2020
• Est. completion date: July 1, 2021

Study information

• Verified date: January 2021
• Source: Cambridge University Hospitals NHS Foundation Trust
• Contact: Louise E Allen, MBBS MD
• Phone: 07941666981
• Email: louise[@]louiseallen.com
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

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.

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 NHS 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.

Recruitment information / eligibility

• Status: Recruiting
• Enrollment: 250
• Est. completion date: July 1, 2021
• Est. primary completion date: July 1, 2021
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 5 Years to 85 Years

Eligibility

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

Related Conditions & MeSH terms

• Amblyopia
• Amblyopia Suspect
• Vision Disorders
• Vision, Low
• Visual Impairment

Intervention

Device:
• DigiVis visual acuity app
Self-testing of visual acuity app on two occasions

Locations

Country	Name	City	State
United Kingdom	Cambridge University Hospitals NHS Trust	Cambridge	Cambs

Sponsors (1)

Lead Sponsor	Collaborator
Cambridge University Hospitals NHS Foundation Trust

Country where clinical trial is conducted

United Kingdom, 

References & Publications (2)

Bastawrous A, Rono HK, Livingstone IA, Weiss HA, Jordan S, Kuper H, Burton MJ. Development and Validation of a Smartphone-Based Visual Acuity Test (Peek Acuity) for Clinical Practice and Community-Based Fieldwork. JAMA Ophthalmol. 2015 Aug;133(8):930-7. doi: 10.1001/jamaophthalmol.2015.1468. Erratum in: JAMA Ophthalmol. 2015 Sep;133(9):1096. — View Citation

Rono HK, Bastawrous A, Macleod D, Wanjala E, Di Tanna GL, Weiss HA, Burton MJ. Smartphone-based screening for visual impairment in Kenyan school children: a cluster randomised controlled trial. Lancet Glob Health. 2018 Aug;6(8):e924-e932. doi: 10.1016/S2214-109X(18)30244-4. Erratum in: Lancet Glob Health. 2018 Oct;6(10):e1072. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Comparison of visual acuity measurement using DigiVis testing and standard visual acuity testing	Measurement bias in logMAR units between DigiVis testing and standard visual acuity testing score compared to	within 30 days
Primary	Levels of Agreement between DigiVis testing and standard visual acuity testing	Upper and lower levels of agreement measured in logMAR units	within 30 days
Secondary	DigiVis test repeatability	Measurement of test-retest variability	within 30 days