Purpose: To investigate and compare the latency and amplitude of the electroretinogram (ERG) photopic negative response (PhNR) between young and old Lewis rats.
Methods: Thirteen Lewis rats were divided into two groups according to ages, young group (3-month old n=5) and old group (24 month old n=8). The ERGs of the left eyes were measured and the latency and amplitude of a-wave, b-wave and PhNRs were recorded and compared according to ages. The mean values between two groups were statistically analysed by t-test.
Results: The latency of PhNRs were evidently prolonged in old group and showed significant difference (P<0.05). There was no statistically significant difference between two groups regarding the amplitude and latency, and no significant difference was noted in the amplitude of PhNRs.
Conclusion: The prolonged latency of PhNR in aged rats possibly associate with the influence of aging upon retinal ganglion cell layer (RGCL).