Background: Devic’s disease is a progressive disease with visual loss. This study was performed to compare the changes in visual evoked potential in Devis patients and healthy subjects attending to Basir clinic in 2013 and 2014.

Materials and methods: In this cross-sectional descriptive study, 25 Devic’s patients and 25 healthy subjects attending to Basir clinic in 2013 and 2014 were enrolled and their VEP results were determined and compared between two groups. Data analyses were performed using t- test.

Results: The mean (± standard deviation) voltages in case and control groups were 4.4±2.8 microvolt and 6.2±2.3 microvolt, respectively (P=0.023). The mean latency was 105.3±10.8 millisecond in case group and 95.6±8.8 millisecond in control group (P=0.001).

Conclusion: Totally, according to the obtained results in this study and comparison with other studies it may be concluded that Devic’s disease would result in decreased voltage and increased latency in VEP of the patients.

Keywords: Visual evoked potential (VEP), Devic’s disease.