Recognition Perimetry Using High Pass Filtered Letter Targets
Research type
Research Study
Full title
Recognition perimetry using high pass filtered letter targets in normal subjects and patients with glaucoma
IRAS ID
127903
Contact name
Roger S. Anderson
Contact email
Sponsor organisation
University College London
Research summary
Glaucoma is the second leading cause of blindness and results in the death of ganglion cells in the retina which produces visual field defects. Visual field testing therefore plays an important role in the diagnosis and monitoring of glaucoma. Standard automated perimetry is considered to be the current gold standard test however, it is widely recognised that the correlation between structural changes (retinal ganglion cell density) and function (sensitivity to the spots of light in the test) is not always clinically demonstrable. It has been reported that 30 to 50% of retinal ganglion cells may be lost before a visual field defect is measured with current tests. High pass resolution perimetry was developed in an attempt to measure thresholds that are more closely related to ganglion cell density. It uses a ring stimulus presented on a grey background and measures detection thresholds of these stimuli. Previous work that our group has done with High Pass Filtered letter targets (Vanishing Optotype letters) which have a similar construction to the ring stimulus have shown that it is actually the recognition thresholds and not detection thresholds which reflect ganglion cell density in the periphery. We therefore wish to develop a visual field test using these targets which may more accurately detect this change.
REC name
London - Brent Research Ethics Committee
REC reference
14/LO/0167
Date of REC Opinion
22 Jan 2014
REC opinion
Favourable Opinion