Evaluating the accuracy of picture and letter visual acuity tests
Research type
Research Study
Full title
Evaluating the sensitivity and specificity of crowded picture visual acuity tests compared to a crowded letter visual acuity test for identifying reduced vision.
IRAS ID
294008
Contact name
Anna O'Connor
Contact email
Sponsor organisation
Alder Hey NHS Foundation Trust
Duration of Study in the UK
1 years, 3 months, 0 days
Research summary
The research investigates the accuracy of visual acuity (the ability of the visual system to discern fine distinctions in the environment measured using printed or projected visual stimuli) (VA) testing in relation to sensitivity (ability of a test to correctly identify patients with a disease) and specificity (the ability of a test to correctly identify people without the disease). A VA test is undertaken by every patient who attends an Ophthalmology clinic from picture-based VA tests, to letter-based depending on cognitive ability and age. It is common in Ophthalmology practice to move on to letter-based VA tests as soon as possible as it is believed to be more accurate. Evidence shows that picture-based VA tests has a high testability and test-retest variability. However, there is no evidence to suggest that letter-based VA tests are more accurate than picture-based VA test in relation to sensitivity and specificity. Therefore, the aim of the research is to investigate and compare the sensitivity and specificity of letter and picture-based VA testing in detecting reduced vision. This would provide evidenced based practice for daily ophthalmology practice.
Participants will be patients who already attend the Ophthalmology department at Alder Hey Hospital or its community sites (May Logan clinic or South Liverpool Treatment Centre) for their scheduled appointment. If a sibling is brought to the appointment too, they will also be invited to participate. Participants will also be staff at Alder Hey and Orthoptic Students at University of Liverpool. Participants at the University of Liverpool will be tested there. Participants will be 5 years old or older. They will be asked to do a letter vision test and two different picture vision tests with their right eye and left eye. Therefore, 6 tests in total.Testing will take no longer than 15 minutes. They will be asked to verbally say the letters/pictures or match the letters/picture to a matching card depending on ability.
REC name
Yorkshire & The Humber - Bradford Leeds Research Ethics Committee
REC reference
21/YH/0196
Date of REC Opinion
16 Aug 2021
REC opinion
Further Information Favourable Opinion