Visual and Functional Assessment in Low Vision Patients

University of Oxford

Status: Completed

Conditions: Inherited Retinal Dystrophies; Age-related Macular Degeneration; Retinitis Pigmentosa; Optic Nerve Pathology

Study type: Observational

Funder types: Other

Identifiers

NCT01876147

OxfordVA2013

Details and patient eligibility

About

Vision testing is a fundamental part of every optometry and ophthalmology assessment. Traditional vision testing charts are not able to measure vision below a certain level. Vision in this range is classified as counting fingers (CF), hand movements (HM) and light perception (LP). These measures are not very accurate or easily quantifiable. They are also poorly understood in terms of impact on quality of life. This study aims to assess new methods for measuring the vision of patients with very low vision.

Full description

Assessing very low vision accurately is becoming increasingly important with the increase in research in this area, such as using retinal implants to restore vision. Without being able to accurately measure the change in vision before and after treatment, it is not possible to fully assess the effect of treatment.

The Freiburg Vision Test (FrACT) is a computer based test developed to assess patients down to the LP level. It has been used in research in recent years. The FrACT is suitable for research but is not suitable for a clinical setting. The Berkeley Rudimentary Vision Test (BRVT) works on a similar principal as the FrACT but consists of hand held cards shown to the patient. Little work has been completed on how well the BRVT test works. Results from FrACT and BRVT will be compared in a group of patients with very low vision. This is important to establish how easily research results can be applied to a clinical setting.

Patients will also be asked to complete a daily living survey to better understand the impact of such poor vision on the ability to carry out day to day tasks. This understanding will help guide low vision services for patients as well as help direct low vision research to achieve a useful level of functional vision.

Enrollment: 50 patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Snellen VA or equivalent ≤ 6/60 in both eyes
• Patient has capacity to give consent and to undertake vision tests

Exclusion criteria

• Diagnosis of functional vision loss
• Unwilling and/or unable to sign informed consent and complete the vision tests

Trial design

50 participants in 2 patient groups

Order of vision tests 1

Description:

Undergo testing with BRVT first, FrACT second.

Order of vision tests 2

Description:

Undergo testing with FrACT first, BRVT second.