97th DOG Annual Meeting 1999
NORMAL VALUES OF THE MULTIFOCAL ERG WITH MONITOR-
B. A. E. Mazinani, A. W. A Weinberger, L. Najjari, C. Dahlke, T. Kube,
Purpose: To obtain reference values for the multifocal ERG by monitorstimulation as well as by SLO-stimulation; to test age dependence and repeatability and to compare monitor- and SLO-stimulation.
Methods: 73 normal volunteers aged 20 to 73 (mean: 49 ± 20 years) were examined with a RETIscan device (Roland Consult, Wiesbaden). 63 subjects were stimulated with an ELSA 20"-VGA-Monitor and a stimulation array with the resolution of 61 hexagons. 15 subjects were stimulated with a Scanning Laser Ophthalmoscope (Rodenstock Instr.) with a resolution of 37 hexagons.
Reference values were obtained for the implicit times and amplitudes of the b wave. Coefficients of correlation were calculated between age and amplitude to test age dependence. 10 volunteers underwent repeated recordings and coefficients of variation were calculated to test reproducability. Furthermore 10 subjects were examined at both eyes to test
differences with coefficients of variation, also.
Results: The implicit times of the b wave amounted to 35 ± 2 ms (monitor) and 35 ± 1 ms (SLO). (No significant difference at p<0,05). The amplitude of the b wave came to 37 ± 15 nV (monitor) and 159 ± 24 nV (SLO). The amplitudes generated by monitorstimulation were significantly smaller than the ones generated by SLO-stimulation (p<0,05). The coefficients of correlation of age dependence were all smaller than 0,2 and not significant. The coefficients of variation for repeated measures amounted between 0,3 and 0,6 for all parameters. The comparison of both eyes of the subjects came to a coefficient of variation of 0,16.
Conclusions: Because of the great interindividual fluctuation margin
of obviously healthy subjects, an intraindividual comparison of both eyes is
suggested to detect unilateral pathological conditions.
Augenklinik der RWTH Aachen, Pauwelsstr. 30, 52074 Aachen