Visual and Functional Assessment in Low Vision Patients

A Randomised Crossover Study to Assess the Usability of Two New Vision Tests in Patients With Low Vision, and Relationship of the Measures to Daily Living Tasks.

Status

Completed

Phases

Unknown

Study type

Observational

Source

ClinicalTrials.gov

Registry ID

NCT01876147

Enrollment

Registered

2013-06-12

Start date

2013-08-31

Completion date

2016-03-31

Last updated

2019-06-13

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Age-related Macular Degeneration, Inherited Retinal Dystrophies, Optic Nerve Pathology, Retinitis Pigmentosa

Keywords

Low vision, Vision testing, Retinitis Pigmentosa, AMD, Visual acuity, Poor vision, Quantification

Brief summary

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.

Detailed 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.

Interventions

None listed

Study design

Observational model

CASE_CROSSOVER

Time perspective

PROSPECTIVE

Eligibility

Sex/Gender

ALL

Age

18 Years to No maximum

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

Design outcomes

Primary

Measure	Time frame
Comparison of VA measured with FrACT and BRVT vision tests	Single visit

Secondary

Measure	Time frame	Description
Relationship between VA and ability to carry out daily living tasks.	Single time point	Results from a daily living skills survey will be related to VA measured by FrACT testing.

Countries

United Kingdom

Outcome results