Normal values of pattern reversal visual evoked potentials (PRVEP) and pattern electroretinography (PERG) in healthy adults in Sri Lanka

Abstract

Background: Visual electrophysiological tests can be used effectively to evaluate the functional integrity of retina and post retinal pathways. The main aim of this study was to determine the normal values for pattern reversal visual evoked potentials (PRVEP) and pattern electroretinography (PERG) in a group of healthy adults in Sri Lanka. Methods: Fifty healthy adults were recruited for the study. PRVEP and PERG tests were performed using surface skin electrodes. Amplitude (μV) and peak latency (msec) values of N75, P100 and N145 components in PRVEP and N35, P50 and N95 components in PERG were measured. Mean values of each PRVEP and PERG measures in both sides were compared between males and females using independent sample t-test to determine the effect of gender on those measures. Results: There were 11 males and 39 females (age range: 20-62, mean (SD): 37.2 (10.94) years). There was no significant difference in PRVEP or PERG measures with regard to gender. Conclusions: Only few studies are reported on normative data of PRVEP and PERG in the world. Ideally, each laboratory has to establish normal values for its own equipment and patient population. However, the normal values of PRVEP and PERG in normal healthy adults obtained in this study would be of immense value to evaluate the patients with several post retinal and retinal disorders in the future visual electrophysiological studies done in Sri Lanka using the similar technical parameters