Age-related changes in the flash electroretinogram and oscillatory potentials in individuals age 75 and older

OBJECTIVES: To evaluate whether the inner plexiform layer of the retina is altered during senescence by examining the oscillatory potentials (OPs) of the flash electroretinogram (fERG) in individuals age 75 and older. DESIGN: Cross-sectional, observational study. SETTING: A university-based center. PARTICIPANTS: Fifty-six healthy volunteers (age 20-88 years). MEASUREMENTS: fERGs and OPs were first evaluated in scotopic conditions, fo llowing pupillary dilation and dark adaptation, in young (20-32 years; n = 30) and older (75-88 years; n = 26) individuals. Electrical signals were re corded with a Dawson-Trick-Litzkow type (DTL) fiber electrode in response t o blue and white flashes. Red flashes were subsequently delivered to the te st eye for photopic fERG and OP recordings following a period of light adap tation. RESULTS: The amplitude of the a- and b-waves in response to blue and white flashes was, significantly decreased in older people and their implicit tim e was increased. The latency of the a- and b-waves under photopic condition s was also prolonged with senescence, but only the amplitude of the b-wave was reduced. The amplitude of most OPs recorded under both scotopic and pho topic conditions decreased with age, whereas their implicit times were prol onged. CONCLUSIONS: Our results confirm previous findings regarding the age depend ency of the fERG a- and b-waves. Furthermore, we provide novel information concerning the detrimental effects of age on the OPs, indicating that the n euronal elements within the inner plexiform, layer of the retina are compro mised with senescence.