Objective To study the response of the retinal neuronal adaptive system to changes of background illumination (BG) by measuring the oscillatory potentials (OPs) and the a- and b-waves of the electroretinogram (ERG) in different BG illuminations. Methods The a- and b-wave and the digitally filtered OPs were simultaneously recorded from Wistar Fu rats aged from 25 to 29 days during dark adaptation (DA) and during 6~8 minutes of BG illuminations at four levels increased successively by steps of two log units, i.e., ldquo;low scotopic rdquo; level of 1.43 times;10-6cd/m2, ldquo;high scotopic rdquo; of 1.43 times;10-4cd/m2 , ldquo;low mesopic rdquo; of 1.43 times;10-2cd/m2 and ldquo;high mesopic rdquo; of 1.43 times;10-2cd/m2. Full field stimulus flashes of 75 msec duration and 1.43 times;10-2cd/m2intensity was delivered at an interval of 1 minute. Results Five OP wavelets were recorded in DA and during scotopic BG illuminations. The number of wavelets was reduced to three as the eyes were exposed to mesopic BG levels. However, the sum of OPs amplitudes (SOPs) increased as the BG was intensified, except at ldquo;high mesopic rdquo; level, by which a significant decrease of SOPs occurred. The amplitudes of the a-and b-waves remained unchanged at the two scotopic BG and decreased as the BG intensity increased to mesopic levels. Conclusion The response of retinal neural adaptive system of the Albino rat to changes of BG light is more sensitive and robust than the slow components of the ERG. The enhancement of the oscillatory responses at ldquo;low mesopic rdquo; illumination level suggests that using proper BG light may be conducive to reducing the variation of OPs. (Chin J Ocul Fundus Dis, 2001,17:286-288)
Citation: WANG Ling.. Effect of background light intensity on the slow components and the oscillatory potentials of the electroretinogram. Chinese Journal of Ocular Fundus Diseases, 2001, 17(4): 286-288. doi: Copy