Tangent versus bowl perimetry: an exploratory study (version 1.0)
Research type
Research Study
Full title
Perimetric sensitivity and response variability with computer based tangent perimetry and bowl perimetry: an exploratory study
IRAS ID
91395
Contact name
David F. Garway-Heath
Contact email
Sponsor organisation
Moorfields Eye Hospital
Research summary
Standard Automated Perimetry (SAP) is currently the gold standard test for visual loss owing to glaucoma. This test normally involves the patient siting at a machine, looking at a central light and pressing a button whenever small spots of light (targets) appears in the peripheral vision. Traditionally these spots of light are projected into a bowl (concave surface) but more recently computer monitor shave been used. These have the advantage of being relatively inexpensive, more readily available and more portable. However tangent computer monitors and bowl perimeter tests and different measurement scales and the relationship between measurements has not been adequately defied. If the advantages of computer monitors are to be brought the visual field assessment the dynamic range of computer screens (different between maximum and minimum intensities of the targets) and the relationship with current gold standard bowl screens needs to be investigated.
A classic method of finding the limit of visual performance is the 'frequency of seeing' method, whereby visual targets of different intensities are displayed and the test keeps a tally of how many times the patient saw the target at these different levels. Such an approval allows investigators to compare the variability of each test, and account for it, thereby allowing the results of the tests to be compared on an equal basis.
We wish to carry out a study which will allow us to compare the variability that accompanies testing, when the targets are projected into a bowl or displayed on a computer monitor. Twenty Five participants will be recruited. After establishing eligibility with some standard ophthalmic tests participants will be asked to carry out two types of visual field test, one using a bowl, the other using a computer monitor. Testing will take approximately 2hrs 30 mins and will be completed in one visit.
REC name
South Central - Oxford B Research Ethics Committee
REC reference
13/SC/0533
Date of REC Opinion
25 Jul 2014
REC opinion
Further Information Favourable Opinion