97th DOG Annual Meeting 1999
MULTIFOCAL ELECTRORETINOGRAM IN PATIENTS WITH RETINAL VEIN OCCLUSION
A. W. A. Weinberger, L. Najjari, C. Dahlke, T. Kube, S. Wolf
Background: The multifocal ERG (mf-ERG) allows a diffentiated topographical analysis of macular responses. In disease like AMD and macular hole a circumscribed or focal reduction of amplitudes in the mf-ERG could be observed. In this study we evaluated changes in the mf-ERG in patients with retinal central- (CRVO) or branch vein occlusion (BRVO).
Methods: In this study 12 patients with CRVO and 10 patients with BRVO were included. The mf-ERG's recorded and compared to the fellow eye (CRVO or the non- affected hemisphere of the affected eye (BRVO). Minimal visual acuity for inclusion was 20/200. For stimulation and mf-ERG recording a system from Roland Consult (Wiesbaden) was used. Stimulation was conducted with a VGA-monitor with 61 fields and in a 24º field of view. Statistical analysis was performed using the Mann-Whitney-non-parametrical test (significance for p<0,05).
Results: Patients with CRVO showed a significant reduction of the b-amplitude means of sum potentials compared to their normal fellow eyes (p = 0.02). In BRVO patients the b-amplitude means of sum potentials in the affected retinal hemisphere were also significantly reduced (p = 0,042)
Conclusion: The analysis of mf-ERG's in patients with retinal vein occlusion shows reduced mean b-amplitudes in affected eyes or retinal hemispheres. In some cases with BRVO the differences were surprisingly small for the clinical appearance and visual acuity. We believe that a lack of fixation due to foveal involvement in these cases contributes to these results. Fixation control and correction will increase the value of this new diagnostic tool.
Augenklinik der Med. Fak. der RWTH Aachen, Pauwelsstr. 30,
D - 52057 Aachen
Augenklinik der Universität Leipzig, Liebigstraße 10-14, D - 04103 Leipzig