Naohisa Umeya1, Izuru Miyawaki2, Hiroshi Inada2. 1. Preclinical Research Unit, Drug Research Division, Sumitomo Pharma Co. Ltd, 3-1-98 Kasugade-naka, Konohana-ku, Osaka, 554-0022, Japan. naohisa.umeya@sumitomo-pharma.co.jp. 2. Preclinical Research Unit, Drug Research Division, Sumitomo Pharma Co. Ltd, 3-1-98 Kasugade-naka, Konohana-ku, Osaka, 554-0022, Japan.
Abstract
PURPOSE: We studied the conditions under which c-waves of the electroretinogram (ERG), that represent retinal pigment epithelium (RPE) function, were detectable using an alternating current (AC) amplifier and whether the c-wave recorded using an AC amplifier was useful for evaluating RPE function. METHODS: We recorded ERG responses in rats to 5 s stimuli under the conditions in which the low-cut frequency and the stimulus luminance were varied. In addition, changes in ERGs were studied after intravenous injection of sodium iodate (SI) to induce RPE degeneration. RESULTS: The c-wave was detected clearly when the frequency of the low-cut filter was set at 0.01 Hz and light stimulus luminances were ≥ - 1.0 log cd/m2. The c-wave was attenuated earlier than other waves (e.g., a-wave and b-wave) after SI administration. CONCLUSIONS: The c-wave was easily detectable using an AC amplifier with the low-cut filter set at 0.01 Hz. Using the AC amplifier may allow easier c-wave recording, compared with the conventional use of a direct current (DC) amplifier, and could be useful for evaluating RPE function.
PURPOSE: We studied the conditions under which c-waves of the electroretinogram (ERG), that represent retinal pigment epithelium (RPE) function, were detectable using an alternating current (AC) amplifier and whether the c-wave recorded using an AC amplifier was useful for evaluating RPE function. METHODS: We recorded ERG responses in rats to 5 s stimuli under the conditions in which the low-cut frequency and the stimulus luminance were varied. In addition, changes in ERGs were studied after intravenous injection of sodium iodate (SI) to induce RPE degeneration. RESULTS: The c-wave was detected clearly when the frequency of the low-cut filter was set at 0.01 Hz and light stimulus luminances were ≥ - 1.0 log cd/m2. The c-wave was attenuated earlier than other waves (e.g., a-wave and b-wave) after SI administration. CONCLUSIONS: The c-wave was easily detectable using an AC amplifier with the low-cut filter set at 0.01 Hz. Using the AC amplifier may allow easier c-wave recording, compared with the conventional use of a direct current (DC) amplifier, and could be useful for evaluating RPE function.
Authors: Daphne L McCulloch; Michael F Marmor; Mitchell G Brigell; Ruth Hamilton; Graham E Holder; Radouil Tzekov; Michael Bach Journal: Doc Ophthalmol Date: 2014-12-14 Impact factor: 2.379