Interpreting the multifocal visual evoked potential: the effects of refractive errors, cataracts, and fixation errors.
OBJECTIVE
To understand how refractive errors, cataracts, and fixation errors affect multifocal visual evoked potential (mfVEP) responses.


METHODS
Monocular mfVEP responses were obtained using a pattern reversal dartboard display. For the control condition, visual acuity was corrected to > or =20/20 and foveal fixation was maintained. The right eye was tested under the following conditions: simulated refractive error, simulated cataract, steady eccentric fixation, and unsteady fixation.


RESULTS
No subject demonstrated significant abnormalities under control conditions. For the simulated refractive error condition, significant centrally located abnormalities were seen for all subjects. For the simulated cataract condition, significant abnormalities were found for three subjects. The steady eccentric fixation condition yielded abnormalities in both eyes for all subjects while the unsteady fixation condition yielded significant central abnormalities in the tested eye. With eccentric and unsteady fixation conditions, all subjects had at least one sector with a waveform polarity reversal.


CONCLUSIONS
While the mfVEP is a useful tool for identifying local optic nerve damage or ruling out non-organic aetiology of visual field defects, factors such as uncorrected refractive errors, cataract, eccentric fixation, and unsteady fixation can produce apparent field defects on the mfVEP. With care, these problems can be correctly identified.
Winn
B J
BJ
Department of Psychology, Columbia University, New York, NY 10027, USA.
Shin
E
E
Odel
J G
JG
Greenstein
V C
VC
Hood
D C
DC
D000328:Adult; D002386:Cataract / Q000503:physiopathology*; D016000:Cluster Analysis; D005074:Evoked Potentials, Visual; D006801:Humans; D008875:Middle Aged; D011336:Probability; D012030:Refractive Errors / Q000503:physiopathology*; D015357:Vision Disparity; D015349:Vision, Monocular
Invest Ophthalmol Vis Sci. 2000 Nov;41(12):4032-8
11053309
J Neuroophthalmol. 2000 Sep;20(3):159-62
11001190
Am J Ophthalmol. 2002 Jan;133(1):29-39
11755837
Vision Res. 2002 Jun;42(12):1513-21
12074946
Doc Ophthalmol. 2002 May;104(3):287-302
12076017
Doc Ophthalmol. 2002 May;104(3):303-20
12076018
J Glaucoma. 2003 Feb;12(1):3-15
12567104
Invest Ophthalmol Vis Sci. 2003 Mar;44(3):1364-75
12601070
Prog Retin Eye Res. 2003 Mar;22(2):201-51
12604058
J Neuroophthalmol. 2003 Dec;23(4):279-89
14663311
Invest Ophthalmol Vis Sci. 2004 Feb;45(2):492-8
14744890
J Vis. 2004;4(1):32-43
14995897
J Am Optom Assoc. 1979 Jan;50(1):19-30
310823
Am J Ophthalmol. 1986 Jun 15;101(6):706-9
3717255
Arch Ophthalmol. 1988 Sep;106(9):1252-4
3046588
Doc Ophthalmol. 1988 May;69(1):25-39
3168709
Graefes Arch Clin Exp Ophthalmol. 1989;227(2):157-61
2721985
Ophthalmology. 1991 Jul;98(7):1066-70
1891215
Arch Ophthalmol. 1991 Dec;109(12):1684-9
1841576
Ophthalmology. 1993 Apr;100(4):511-7
8479709
Electroencephalogr Clin Neurophysiol. 1994 Jan;90(1):65-81
7509275
Invest Ophthalmol Vis Sci. 1998 May;39(6):937-50
9579473
Clin Neurophysiol. 1999 Oct;110(10):1793-800
10574294
J Glaucoma. 2000 Feb;9(1):10-9
10708226
Invest Ophthalmol Vis Sci. 2000 May;41(6):1580-7
10798679
Doc Ophthalmol. 2000;100(2-3):115-37
11142742