title: The determination of dark adaptation time using electroretinography in conscious miniature Schnauzer dogs.
abstract: The optimal dark adaptation time of electroretinograms (ERG's) performed on conscious dogs were determined using a commercially available ERG unit with a contact lens electrode and a built-in light source (LED-electrode). The ERG recordings were performed on nine healthy Miniature Schnauzer dogs. The bilateral ERG's at seven different dark adaptation times at an intensity of 2.5 cd.s/m(2) was performed. Signal averaging (4 flashes of light stimuli) was adopted to reduce electrophysiologic noise. As the dark adaptation time increased, a significant increase in the mean a-wave amplitudes was observed in comparison to base-line levels up to 10 min (p < 0.05). Thereafter, no significant differences in amplitude occurred over the dark adaptation time. Moreover, at this time the mean amplitude was 60.30 +/- 18.47 microV. However, no significant changes were observed for the implicit times of the a-wave. The implicit times and amplitude of the b-wave increased significantly up to 20 min of dark adaptation (p < 0.05). Beyond this time, the mean b-wave amplitudes was 132.92 +/- 17.79 microV. The results of the present study demonstrate that, the optimal dark adaptation time when performing ERG's, should be at least 20 min in conscious Miniature Schnauzer dogs.
authors.affiliation: Department of Veterinary Surgery and Ophthalmology, College of Veterinary Medicine and BK21 Program for Veterinary Science, Seoul National University, Seoul 151-742, Korea.
authors.forename: Hyung-Ah
authors.initials: HA
authors.lastname: Yu
authors.forename: Man-Bok
authors.initials: MB
authors.lastname: Jeong
authors.forename: Shin-Ae
authors.initials: SA
authors.lastname: Park
authors.forename: Won-Tae
authors.initials: WT
authors.lastname: Kim
authors.forename: Se-Eun
authors.initials: SE
authors.lastname: Kim
authors.forename: Je-Min
authors.initials: JM
authors.lastname: Chae
authors.forename: Na-Young
authors.initials: NY
authors.lastname: Yi
authors.forename: Kang-Moon
authors.initials: KM
authors.lastname: Seo
mesh_terms: D000818:Animals; D003623:Dark Adaptation / Q000502:physiology*; D004285:Dogs / Q000502:physiology*; D004596:Electroretinography / Q000662:veterinary*; D008297:Male; D012160:Retina / Q000502:physiology*; D013997:Time Factors