Angioscotoma detection with fundus-oriented perimetry: A study with dark and bright stimuli of different sizes

Fundus-oriented perimetry (FOP) was used to evaluate the effectiveness of different-sized bright and dark stimuli in detecting and quantitatively measuring angioscotoma. The foveolas and optic disks of digitized fundus images were aligned with their psychophysical counterparts to construct individua...

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Bibliographic Details
Published in:Vision research (Oxford) 1999-05, Vol.39 (10), p.1897-1909
Main Authors: Schiefer, U., Benda, N., Dietrich, T.J., Selig, B., Hofmann, C., Schiller, J.
Format: Article
Language:English
Subjects:
Adult
Angioscotoma
Biological and medical sciences
Dark stimulus
Diseases of visual field, optic nerve, optic chiasma and optic tracts
Female
Fundus Oculi
Fundus-oriented perimetry
Humans
Light
Male
Mathematics
Medical sciences
Ophthalmology
Psychophysics
Retinal Vessels
Scotoma - diagnosis
Sensory Thresholds - physiology
Signal-to-noise ratio
Stimulus size
Visual Field Tests
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Description
Summary:Fundus-oriented perimetry (FOP) was used to evaluate the effectiveness of different-sized bright and dark stimuli in detecting and quantitatively measuring angioscotoma. The foveolas and optic disks of digitized fundus images were aligned with their psychophysical counterparts to construct individual grids of perimetric stimuli. Each grid included a linear set of test point locations crossing a retinal vessel. Angioscotomas immediately became visible in nine of 13 healthy normal volunteers tested with FOP. Additional mathematical processing of local loss of differential light sensitivity (dls) disclosed an angioscotoma for at least one stimulus condition in all persons tested. The angioscomas were usually deeper for small (12′) targets than for large (32′) ones. On the other hand, the overall noise at dls thresholds was generally higher for small than for large stimuli regardless of whether the stimuli were bright or dark. No noteworthy differences were found in detection rates or signal-to-noise ratios under different stimulus conditions (dark/bright/small/large). FOP permits the individual arrangement of stimuli for specific morphological conditions and is thus capable of detecting even minute visual field defects such as angioscotomas.
ISSN:0042-6989
1878-5646
DOI:10.1016/S0042-6989(98)00295-8