From immature to mature pattern ERG and VEP.

Electrophysiological parameters in children reflect not only pathological processes, but also maturation of the visual system. This review investigates PERG and PVEP changes in infants and schoolchildren in order to establish the time scale for electrophysiological maturation of the visual system. Studies using pattern-reversal and pattern-onset stimulation are presented. Maturational changes have been found to be rapid in infants and gradual in schoolchildren. PERG age-related changes in infants were seen as a decrease in latency and in schoolchildren as a decrease in amplitude. PVEP age-related changes in infants were seen as a decrease in latency, an increase in amplitude and the development of the waveform. In schoolchildren, PVEP changes were more gradual, with a decrease in latency, a decrease in amplitude and transformation of the waveform. In conclusion, electrophysiological maturation proceeds until adulthood. Therefore, in paediatric clinical work, normative values in infants and schoolchildren are an important factor in differentiating maturation of the visual system from pathological processes.