Clinical trial NCT01876147: Visual and Functional Assessment in Low Vision Patients
Official title: 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.
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Retinitis Pigmentosa
Age-related Macular Degeneration
Optic Nerve Pathology
Inherited Retinal Dystrophies
Keywords: Low vision
Vision testing
Retinitis Pigmentosa
AMD
Visual acuity
Poor vision
Quantification
Lead sponsor: University of Oxford
Sponsor class: OTHER
First posted: 2013-06-12
Enrollment: 50
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: CASE_CROSSOVER
Time perspective: PROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: Patients with low vision attending outpatient clinics in Oxford Eye Hospital.

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.

Eligibility criteria: 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

Primary outcomes:
measure: Comparison of VA measured with FrACT and BRVT vision tests
timeFrame: Single visit
Secondary outcomes:
measure: Relationship between VA and ability to carry out daily living tasks.
timeFrame: Single time point
Other outcomes:
Locations:
city: Oxford
country: United Kingdom
facility: Oxford University Hospitals NHS Trust
state: Oxfordshire
Study officials:
affiliation: University of Oxford
name: Robert E MacLaren, DPhil
role: PRINCIPAL_INVESTIGATOR
References:
citation: Jolly JK, Gray JM, Salvetti AP, Han RC, MacLaren RE. A Randomized Crossover Study to Assess the Usability of Two New Vision Tests in Patients with Low Vision. Optom Vis Sci. 2019 Jun;96(6):443-452. doi: 10.1097/OPX.0000000000001380.