Purchase this article with an account.
Rika Hirota, Mineo Kondo, Shinji Ueno, Takao Sakai, Toshiyuki Koyasu, Hiroko Terasaki; Photoreceptor And Post-photoreceptoral Contributions To Photopic ERG A-wave In Rhodopsin P347L Transgenic Rabbits. Invest. Ophthalmol. Vis. Sci. 2012;53(14):2443.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
This study was conducted to determine the cone photoreceptors and post-photoreceptoral contributions to photopic ERG a-wave in rhodopsin Pro347Leu transgenic rabbits, a retinitis pigmentosa model.
Ten transgenic and 10 wild-type rabbits were studied at 4- and 12-months-of-age. The a-waves of photopic ERGs were elicited by xenon flashes of different intensities before and after blocking post-photoreceptoral activities by intravitreal injections of 6-cyano-7-nitrouinoxaline-2,3(1H,4H)-dione and 2-amino-4-phosphonobutyric acid. Percentage photoreceptor contribution was calculated by dividing the a-wave amplitudes before drugs by the amplitudes after drugs.
The cone photoreceptor contribution to the photopic ERG a-wave increased with increasing stimulus strength, and the mean percentage ranged from 54 percents to 75 percents in 4-months-old wild-type. In contrast, the percentage in 4-months-old transgenic ranged from 32 percents to 51 percents. These differences were statistically significant. The percentage in 12-months-old transgenic became still smaller at 11 percents to 48 percents.
These results suggested that the relative contribution of cone photoreceptors to the photopic ERG a-wave is less in the retina with inherited photoreceptor degeneration. These also indicate that the a-wave in patients with retinitis pigmentosa must consider this lower contribution from the photoreceptors.
This PDF is available to Subscribers Only