The Changes of Pattern Reversal Visual Evoked Potentials in Normal Infants

摘要

Purpose: To study pattern reversal visual evoked potential (PVEPs) and determine the developmental character and mature time of visual function in normal infants at different months of age. Methods: PVEPs were recorded from 115 normal infants at 3,6,9,12 moths age. P_1 latency for different checks (1°40′, 25′, 6′) was analyzed and compared to those of normal adults. Changes of N_1 , N_2 latency of PVEPs were also exam-ioned. Results: P_1 latency for all checks (1°40′, 25′, 6′) was significantly longer at 3 months than at 6 months of age (P < 0. 05), but no significant differences can be seen after 6 months of age for larger (1°40′) and intermediate (25′) checks (P > 0. 05). P_1 latency for larger checks (1°40′) reached adult level after 3 months of age, but not for the intermediate check (25′), while P_1 latency for small check (6′) presented the character of fluctuation. Conclusion: The visual system continued to develop after birth and appeared a certain regularity. Our results showed that P_1 latency for larger check (1°40′) reached adult levels after 3 months of age. But P_1 latency for intermediate check still has not reached adult levels after 3 months of age. To determine the age at which adult levels are finally reached, infants of 12 months and older must be tested. The reason why P_1 latency for smaller check (6′) presented the character of fluctuation should be the temporal tuning function developing much more slowly.