1. Nabil El Ayoubi MD, Helen Sawaya, MSc., Raja Sawaya MD.
Visual Evoked Potentials and Retinal Optical Coherence Tomography in Optic Neuropathy
Nabil El Ayoubi MD, Helen Sawaya, MSc., Raja Sawaya MD.
Department of Neurology, American University Medical Center, Beirut, Lebanon.
Purpose:
The aim of this study was to:
1. calculate the average latencies of
f-VEP and PR-VEP in normals
and patients with optic
neuropathy (ON).
2. calculate the average latencies of
retinal nerve fiber layer (RNFL)
and ganglion cell plexiform layer
(GCIPL) by OCT in normals
and patients with ON.
3. correlate f-VEP, PR-VEP, RNFL
and GCIPL in normal and
patients with ON.
Material and method:
We studied 14 normal eyes and 13 eyes with ON. We performed fVEP and PR-VEP with intermittent light and pattern reversal stimulation, monocularly, rate of 2 Hz, checker size of 30°, 150 stimulations. OCT using Spectral-Domain Cirrus®. RNFL and GCIPL were measured. Statistical analysis was performed.
Results:
PR-VEP vs RNFL (in controls)
Mean (SD)
Controls ON
fVEP (ms)
(24.33)
(44.62)
prVEP (ms)
(3.54)
(35.09)
OCT RNFL
98.57 (7.1)
83.18 (20.27)
OCT GCIPL
89.43 (3.74)
71.27 (10.61)
f-VEP and PR-VEP
f-VEP vs GCIPL (in ON)
RNFL and GCIPL by OCT
Conclusion:
In controls PR-VEP is shorter and less variable than f-VEP. It correlates with RNFL size, but not with the GCIPL.
In ON PRVEP is delayed while f-VEP is shorter and variable. In ON f-VEP reflects GCIPL thickness more than PRVEP.