Electroretinography and visual-evoked potential changes in patients with nystagmus

Background and aim Nystagmus is an ocular motility disorder in which the eyes make uncontrollable, repeated movements. These movements can cause vision and depth perception problems, as well as affect balance and coordination. The aim was to study electrophysiological changes that occur in patients with nystagmus and pattern of changes in each disease. Patients and methods A prospective, institutional, clinical trial was conducted on 60 eyes with nystagmus. The age of the patients ranged between 5 and 50 years, and the patients were chosen from Al-Hassan Eye Center, Giza and Al-Azhar University Hospital outpatient clinic. Results The study revealed the relation between photopic electroretinogram (ERG), scotopic ERG, and flash visual-evoked potential (VEP) and each of fundus examination and final diagnosis of the studied group, and it shows highly statistically significant differences between groups according to fundus examination and final diagnosis. Conclusions Electrophysiological examination is an essential step in the assessment of patients with early-onset nystagmus especially when the eyes are apparently normal on routine examination and should be enrolled within their medical records. This study clarified the need to investigate cases with nystagmus by ERG and suggested that the ERG was useful where the diagnosis was uncertain. Visual-evoked potential is complementary to ERG and can be tested simultaneously.