Document Detail

Steady-state electroretinograms and pattern electroretinograms in pigs.
MedLine Citation:
PMID:  11372543     Owner:  NLM     Status:  MEDLINE    
BACKGROUND: Electroretinograms (ERG) or pattern-electroretinograms (PERG) could be valuable for the quantification of potential damage to the pig retina by experimental erbium:YAG laser treatment. We therefore performed a normative study of ERGs and PERGs in pigs. METHODS: We recorded ERGs and PERGs under general anaesthesia in two experiments. In experiment 1 we examined eight eyes from six pigs of 20-25 kg body weight; in experiment 2 we examined four eyes from four pigs of 40-45 kg body weight. We used flash and checkerboard stimuli. In experiment 1, the stimulus parameters were mean luminance 48.3 cd/m2 for checkerboard stimuli, 96.6 cd/m2 for ERG, check sizes of 4 degrees, 8 degrees, and 16 degrees, temporal frequencies were 16 Hz for ERG and 8 rev/s for PERG. Three measurements were repeated after two weeks. Stimulus parameters for experiment 2 were luminance 175 (350) cd/m2, check sizes 1.6 degrees, 3.2 degrees, 6.7 degrees, and 16 degrees, temporal frequencies 6.3 Hz for ERG and 8 rev/s for PERG. Recordings were subjected to Fourier analysis. RESULTS: In experiment 1 the mean ERG amplitude was 1.02 +/- 0.89 microV with a coefficient of variation of 42% for repeat sessions. The mean PERG amplitudes were 0.53 +/- 0.25 microV for 16 degrees checks, 0.36 +/- 0.21 microV for 8 degrees, and 0.25 +/- 0.17 microV for 4 degrees. The mean coefficient of variation between two measurements was 103% for 16 degrees checks, 24% for 8 degrees, and 116% for 4 degrees. In experiment 2 the mean ERG amplitude was 9.72 +/- 3.96 microV. The mean PERG amplitudes were 0.77 +/- 0.50 microV for 16 degrees checks, 0.09 +/- 0.16 microV for 6.7 degrees, 0.07 +/- 0.13 microV for 3.2 degrees, and 0.08 +/- 0.09 microV for 1.6 degrees. CONCLUSIONS: It was possible to record ERGs and PERGs in pigs. However, the ERG amplitudes were small; PERG amplitudes were even smaller in both groups and cannot be reliably recorded. A problem for both ERG and PERG was the high intra-individual and interindividual variability. Therefore, only very extensive damage to the retina by vitrectomy or Er:YAG laser treatment might lead to a significant change in the ERG or PERG amplitudes.
P Janknecht; T Wesendahl; N Feltgen; T Otto; M Bach
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Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Graefe's archive for clinical and experimental ophthalmology = Albrecht von Graefes Archiv für klinische und experimentelle Ophthalmologie     Volume:  239     ISSN:  0721-832X     ISO Abbreviation:  Graefes Arch. Clin. Exp. Ophthalmol.     Publication Date:  2001 Feb 
Date Detail:
Created Date:  2001-05-24     Completed Date:  2001-09-13     Revised Date:  2003-11-14    
Medline Journal Info:
Nlm Unique ID:  8205248     Medline TA:  Graefes Arch Clin Exp Ophthalmol     Country:  Germany    
Other Details:
Languages:  eng     Pagination:  133-7     Citation Subset:  IM    
Univ.-Augenklinik Freiburg, Killianstr. 5, 79106 Freiburg, Germany.
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MeSH Terms
Pattern Recognition, Visual
Photic Stimulation
Reference Values
Retina / physiology*

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