[Aging effects on upper and lower half visual fields by VECPs and automated static perimetry]

We studied the aging effects on upper and lower half visual fields using pattern VECPs with half fields stimuli and automated static perimetry. The subjects, consisting of 56 normal volunteers ranging in age from 10 to 69 years old, were divided into three groups (10-29, 30-49, 50-69 years old). Their visual acuities were better than 1.0 and refractive errors were within +/- 2.0 diopters. Perimetry was performed with an automated perimeter (Octopus, program 61). An artificial pupil of 3 mm was used after cycloplegia with 1% tropicamide to eliminate senile miosis effects in recording of VECPs. Subjective light sensitivity decreased with age and there was a noticeable hiatus between the third and fourth decades. However the age-related decrease in sensitivity showed no difference between the upper and lower half fields. However VECPs results showed that with aging the P100 peak latency did not increase for lower half field stimuli, but increased for the upper half field stimuli, especially for smaller check sizes. These results suggested that there were different aging processes a in the upper and lower half fields and higher neural factors participated in the effects.