98th Annual Meeting DOG 2000

V 29

Central onset hereditary retinal dystrophy: macular dystrophy vs. cone dystrophy

U. Kellner, H. Kraus, M. Arzheimer, H. Schwarz

Background: The differential diagnosis of central onset hereditary retinal dystrophies is difficult especially in early stages. The purpose of this study was to conduct a retrospective analysis of the relevance of functional evaluation in one electrodiagnostic service unit.

Patients & Methods: Between Oct. 1990 and Feb. 2000 450 patients with central onset hereditary retinal dystrophies were examined in one ophthalmic electrodiagnostic service unit. Tests included ophthalmic basic evaluation and in most patients examination of visual fields, color vision, full-field-ERG (ISCEV-Standard), chromatic ERG, and since 1996 multifocal ERG (MERG). EOG, fluorescein angiography and molecular genetic evaluation were performed only in some patients.

Results: Early signs of functional loss in central onset hereditary retinal dystrophies were color vision deficits and reduced amplitudes in the chromatic ERG and MERG. The full field ERG allowed to differentiate between macular and cone dystrophies. Morphologic alterations correlated only moderately with the retinal function and were not sufficient for diagnosis and counselling.

Conclusions: The differential diagnosis of central onset hereditary retinal dystrophies can only be based on a detailed electrophysiologic evaluation. The combination of full-field ERG and MERG at least once at the first examination should be required for an adequate diagnosis and counselling.

Augenklinik, Universitätsklinikum Benjamin Franklin, Freie Universität Berlin, Hindenburgdamm 30, D - 12200 Berlin



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