The effects of optic disc drusen on the latency of the pattern-reversal checkerboard and multifocal visual evoked potentials.
OBJECTIVE
To determine the effect of optic disc drusen on the latency of the pattern-reversal checkerboard visual evoked potentials (VEPs) and multifocal (mf)VEPs and to better understand the pathophysiology of the condition.


METHODS
Eighteen eyes with optic disc drusen (10 patients) and 38 control eyes (19 subjects) underwent VEP, mfVEP, and visual field testing. Only one eye of each individual, the one with the more affected visual field, was used in the analyses. The VEPs were recorded with a 15' and 60' reversing checkerboard pattern, and the mfVEPs were elicited by a 60-sector dartboard display.


RESULTS
Unlike the VEP results, the mfVEP revealed a significant increase in the average monocular latency of the optic disc drusen group compared with that of the control group. The average mfVEP relative latency for the optic disc drusen group (4.1 ms) was greater than that (0.8 ms) in the control group. For monocular and interocular analyses, the average percentage of points delayed in the drusen group was significantly greater than that in the control group.


CONCLUSIONS
Optic disc drusen produced significant latency delays on the mfVEP test but not on the VEP test, presumably due to the mfVEP's ability to detect the effects of local changes. The results are consistent with the hypothesis that local mechanical compression by optic disc drusen leads to abnormal retinal ganglion cell activity.
Grippo
Tomas M
TM
Department of Ophthalmology, The New York Eye and Ear Infirmary, New York, New York 10003-4297, USA.
Ezon
Isaac
I
Kanadani
Fabio N
FN
Wangsupadilok
Boonchai
B
Tello
Celso
C
Liebmann
Jeffrey M
JM
Ritch
Robert
R
Hood
Donald C
DC
D000328:Adult; D000368:Aged; D005074:Evoked Potentials, Visual / Q000502:physiology*; D006801:Humans; D007429:Intraocular Pressure; D008875:Middle Aged; D015594:Optic Disk Drusen / Q000503:physiopathology*; D011930:Reaction Time; D014786:Vision Disorders / Q000503:physiopathology*; D014794:Visual Fields / Q000502:physiology*