Maehara Seiya, Itoh Norihiko, Itoh Yoshiki, Wakaiki Shinsuke, Tsuzuki Keiko, Seno Takahiro, Kushiro Tokiko, Yamashita Kazuto, Izumisawa Yasuharu, Kotani Tadao
Department of Companion Animal Clinical Sciences, School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Hokkaido 069-8501, Japan.
J Vet Med Sci. 2005 May;67(5):509-14. doi: 10.1292/jvms.67.509.
Electroretinography (ERG) is an effective method for the diagnosis of retinal disease. In the dog, dependable ERG recording is difficult without the use of an expensive device like a Ganzfeld full-field stimulator. The International Society for Clinical Electrophysiology of Vision has defined the standard flash stimulus condition (SF) and evaluation of the retina using the b/a ratio in humans. In dogs, evaluation using the b/a ratio has not been reported, whereas the intensity of SF has been defined. In this study, we performed a convenient ERG recording method using a contact lens electrode with a built-in light source (LED-electrode), and confirmed SF as reported previously. ERG recordings were performed on 15 healthy beagle dogs under sedation. We performed bilateral ERG at 12 different intensities after 30 min dark adaptation. After 10 min light adaptation, we recorded single flash cone and flicker cone response using the SF determined in this study. In this study, SF of 3.0 cd/m(2)/sec (6,000 cd/m(2), 0.5 msec) resulted in b/a=2. The intensity for rod response that recorded only the b-wave was 0.0096 cd/m(2)/sec (80 cd/m(2), 0.12 msec). We could achieve ERG for each response easily and smoothly under sedation, and without general anesthesia. Using an LED-electrode, we could perform more quantitative and reproducible ERG examinations than with traditional methods. We propose that the b/a ratio is the most useful parameter in ERG reporting for evaluating retinal function.
视网膜电图（ERG）是诊断视网膜疾病的有效方法。在犬类中，若不使用像全视野刺激器这样昂贵的设备，可靠的ERG记录很难实现。国际视觉临床电生理学会已经定义了标准闪光刺激条件（SF）以及在人类中使用b/a比值评估视网膜。在犬类中，尚未有使用b/a比值进行评估的报道，不过已经定义了SF的强度。在本研究中，我们使用了一种内置光源的隐形眼镜电极（LED电极）进行了便捷的ERG记录方法，并证实了如先前报道的SF。对15只健康的比格犬在镇静状态下进行ERG记录。在暗适应30分钟后，以12种不同强度进行双侧ERG检查。在明适应10分钟后，我们使用本研究确定的SF记录单次闪光视锥细胞和闪烁视锥细胞反应。在本研究中，3.0 cd/m(2)/sec（6,000 cd/m(2)，0.5毫秒）的SF导致b/a = 2。仅记录b波的视杆细胞反应强度为0.0096 cd/m(2)/sec（80 cd/m(2)，0.12毫秒）。在镇静状态下且无需全身麻醉的情况下，我们能够轻松、顺利地获得每种反应的ERG。使用LED电极，我们能够比传统方法进行更定量、可重复的ERG检查。我们提出，b/a比值是ERG报告中评估视网膜功能最有用的参数。
