Multifocal blue-on-yellow visual evoked potentials in early glaucoma.
OBJECTIVE
To determine the sensitivity and specificity of blue-on-yellow multifocal visual evoked potentials (mfVEPs) in early glaucoma.


METHODS
Cross-sectional study.


METHODS
Fifty patients with a confirmed diagnosis of early glaucoma and 60 normal participants.


METHODS
Black-and-white mfVEPs and blue-on-yellow mfVEPs were recorded using the Accumap version 2.0 (ObjectiVision Pty. Ltd., Sydney, Australia). All patients also underwent achromatic standard automated perimetry (SAP).


METHODS
Multifocal VEP amplitude and latency values in glaucoma patients were analyzed and compared with those of the normal controls.


RESULTS
Based on the definition of visual field defect, in the group of glaucomatous eyes with SAP defects, amplitude of blue-on-yellow mfVEP was abnormal in all 64 cases (100% sensitivity), whereas black-and-white mfVEP missed 5 cases (92.2% sensitivity). Generally, larger scotomata were noted on blue-on-yellow mfVEP compared with black-and-white mfVEP for the same eyes. There was high topographic correspondence between SAP and amplitude of blue-on-yellow mfVEP and significant (P<0.0001) correlation between them (correlation coefficient, 0.73). Abnormal amplitude was detected in 3 of 60 eyes of control subjects (95% specificity). There was, however, no correlation between visual field defect and latency delay in glaucoma patients. Although there was a significant difference between averaged latency of control and glaucoma eyes, values considerably overlapped.


CONCLUSIONS
The blue-on-yellow mfVEP is a sensitive and specific tool for detecting early glaucoma based on amplitude analysis.
Klistorner
Alexander
A
Department of Ophthalmology, Save Sight Institute, University of Sydney, Sydney, Australia.
Graham
Stuart L
SL
Martins
Alessandra
A
Grigg
John R
JR
Arvind
Hemamalini
H
Kumar
Rajesh S
RS
James
Andrew C
AC
Billson
Francis A
FA
D000368:Aged; D003430:Cross-Sectional Studies; D003941:Diagnostic Techniques, Ophthalmological; D005074:Evoked Potentials, Visual; D005188:False Negative Reactions; D005902:Glaucoma, Open-Angle / Q000175:diagnosis*; D006801:Humans; D008875:Middle Aged; D009898:Optic Disk / Q000473:pathology; D009901:Optic Nerve Diseases / Q000175:diagnosis*; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012607:Scotoma / Q000175:diagnosis*; D012680:Sensitivity and Specificity; D058609:Visual Field Tests; D014794:Visual Fields