Purpose: To study the ability of pattern reversal visual evoked potentials (VEPs) to detect subclinical visual pathway pathologic assessment in Behcet disease (BD) and correlate VEP results in BD with disease activity and response to corticosteroid treatment. Methods: This study included 18 patients (36 eyes) with BD without recent ocular manifestations and 20 healthy controls (40 eyes). Clinical history was taken, and clinical examinations were done. Visual evoked potential recordings were performed by an electromyographic evoked machine for patients and controls. Corticosteroids were given to patients with extraocular activity, and VEP was repeated after clinical and laboratory improvement of the manifestations. Results: p100 latency of VEP was prolonged in 8 patients (11 eyes) (44.4% of cases). Mean p100 latency showed
statistically significant prolongations in BD group compared with the control group (106.7 6 8.1 ms vs. 99.6 6 1.9 ms) with P value , 0.001. There was a positive correlation between p100 latency and the disease activity score (r ¼ 0.8673), whereas there was no correlation between p100 latency and the disease duration (r ¼ 0.00072). Patients treated with corticosteroids showed statistically significant reduction in mean p100 latency after treatment (P , 0.001). Conclusions: Visual evoked potential may be a valuable tool for detecting subclinical neurologic affection in BD.