Electroretinogram and visual-evoked potentials in children with optic nerve coloboma

The aim was to evaluate alterations in Visual-Evoked Potentials (VEP) and E lectroretinogram (ERG) and discover whether these tests are useful for dete rmining residual visual acuity in cases where a patient is unable to collab orate. Flash and, when possible, Transient Pattern Reversal Visual-Evoked P otentials and Maximal Response ERG were recorded in 8 children (under three years old) affected by different aspects of optic nerve coloboma. None of them had visual acuity evaluated because of poor collaboration. All examina tions were carried out using skin electrodes. Amplitude of the a and b comp onent of ERG, amplitude, morphology and latency of the major components of Flash VEP and amplitude and latency of P100 Pattern Reversal VEP were evalu ated. Four of the patients were examined three years later and visual acuit y was compared with the previous electrofunctional results. Alterations in ERG were found only in the case of significant retinal anomalies ((great co loboma, retinal detachment), huge alterations were found in both Flash VEP and in Pattern Reversal VEP. The retrospective study of VEP traces and visu al acuity showed a good correlation between electrofunctional data and visu al capability. Electrofucntional examinations can identify important conduc tive retinocortical anomalies. The possibility of correlating electrophysio logical results with residual visual acuity is important for rehabilitative management in such optic disc malformations.