Result of Visual Evoked Potential, Electroretinography and Electrooculography in Normal Subjects Using MonPack 3 System

ABSTRACT

PURPOSE: We present the results of visual evoked potential (VEP), electroretinography (ERG), and electrooculography (EOG) in normal subjects using the Mon-pack 3 system (Metrovision). METHODS: VEP, ERG, and EOG were obtained in 92 normal eyes. The measurements followed the International Society for Clinical Electrophysiology of Vision (ISCEV) standardization protocol. In VEP, the standard electrode was placed on the forehead and the active electrode was attached on the occiput. In ERG, a 20-minute dark adaptation was performed after mydriasis, and an ERG-jet electrode was used. EOG was measured by attaching an electrode to each medial canthal skin. Each latent period and electric potential was measured with average, standard deviation, median, and 95% confidencenterval (95% CI). RESULTS: The mean P100 latency in pattern VEP was 104.36 ms, and P100 latency in flash VEP was 116.71 ms. For the maximal ERG response, the implicit times of a and b waves were 22.65 ms and 44.58 ms, respectively and the amplitude of a and b waves were 274.09 microv and 489.52 microv, respectively. For the ERG cone response, the implicit time of a and b waves were 18.21 ms and 33.40 ms, respectively, and the amplitude of a and b waves were 35.87 microv and 104.42 microv, respectively. The mean ERG oscillitatory potential was 285.53 microv. The average EOG Arden ratio was 2.54. CONCLUSIONS: VEP, ERG, and EOG results from normal subjects using the Mon-pack 3 system can be applied to the diagnosis of retina and optic nerve disease and basic research.