Visual evoked potentials in optic nerve injury--does it merit to be mentioned?

The value of Visual Evoked Potentials (VEP) in the management of indirect optic nerve injury was prospectively studied in 78 patients. The initial VEPs were normal in 10, abnormal in 29 and absent in 39 patients. All 10 patients with normal VEP showed visual recovery. Amongst 29 patients with abnormal VEP, 26 (86.6%) showed improvement. In 39 patients initial VEPs showed no wave, however, subsequent VEP recordings demonstrated wave formation. Thus in 31 patients repeated VEP recordings failed to demonstrate wave formation, and none of them improved. This study, thus brings out the high predictive value of both positive and negative VEPs.