MfERG waveform characteristics in the RS1h mouse model featuring a 'negative' ERG.
Several retinal disorders lead to a relatively greater attenuation of the b-wave compared to the a-wave of the electroretinogram (ERG), a constellation called 'negative' ERG. To determine the waveform characteristics of multifocal ERGs (mfERGs) and their dependence on recording parameters in such a case, we studied the Rs1h(-/Y) mouse, the model for x-linked juvenile retinoschisis. mfERGs were recorded with a VERIS 4 system connected to a piggyback stimulator prototype that added the stimulus to the optical pathway of a HRA scanning-laser ophthalmoscope (SLO) by means of a wavelength-sensitive mirror. Real-time fundus visualization was achieved with the infrared laser of the SLO (835 nm). High-pass filter settings and the time interval used by the 'artefact removal' feature were varied to study their influence on the waveform. The mfERG in the Rs1h(-/Y) mouse had a 'negative' shape. However, the high-pass filter setting had to be lowered from the usual 10 Hz down to about 2 Hz in order to obtain that result, otherwise the negative shape was lost and mainly a positive peak remained. Similarly, a short time interval used by the 'artefact removal' feature also removed the negative shape. The Rs1h(-/Y) mouse was found to be a valuable model of diseases with a 'negative' waveform shape also in mfERG. Our results underline the importance of a lower high-pass filter cutoff frequency when recording mfERGs in such disorders. In addition, if the 'artefact removal' feature is used, it should be verified that it doesn't distort the waveform shape.
Seeliger
Mathias W
MW
Retinal Electrodiagnostics Research Group, University Eye Hospital Department II, Schleichstr. 12-16, D-72076 Tübingen, Germany. see@uni-tuebingen.de
Weber
Bernhard H F
BH
Besch
Dorothea
D
Zrenner
Eberhard
E
Schrewe
Heinrich
H
Mayser
Helmut
H
D000818:Animals; D004195:Disease Models, Animal; D004596:Electroretinography; D005654:Fundus Oculi; D008040:Genetic Linkage; D007834:Lasers; D051379:Mice; D008817:Mice, Mutant Strains; D009887:Ophthalmoscopy; D010641:Phenotype; D041441:Retinoschisis / Q000235:genetics* / Q000473:pathology / Q000503:physiopathology*; D014960:X Chromosome