97th DOG Annual Meeting 1999



B. Jurklies1, M. Weismann1, U. Kellner2, M. Seeliger3, N. Bornfeld1

The enhanced s-cone sensitivity syndrome (ESCS) is characterized by absent rod function and large responses due to s-cone hypersensitivity. The purpose was to investigate retinal function and topography in ESCS using multifocal electroretinography (MERG).

Methods: 3 patients were diagnosed as having ESCS based on clinical and ERG criteria. MERG recordings (VERIS, EDI, San Francisco). were obtained in response to a pattern of 103 hexagonal elements in a 30º field. Mean responses of groups with different eccentricity from the center (ring 1) to the periphery (ring 6) were evaluated.

Results: The configuration of MERG-recordings was different in the center and periphery, respectively. Mean responses of the periphery were moderately to severely delayed and were comparable to the findings of the Ganzfeld ERG in both configuration and implicit time . The responses of the center revealed a double peak configuration. The slow component was delayed similar to the responses of the periphery. The fast component was normal to only moderately delayed and similar to responses in a normal control group.

Conclusions: MERG recordings in ESCS were at least in part comparable to the findings of the Ganzfeld ERG. However, central area with features of middle- (MWL) and long wavelength cones (LWL) was detected varying in size between affected individuals. In accordance with psychophysical data this may be responsible for normal color vision. The findings point to an imbalance of LWL/MWL and s-cone mechanisms, respectively.

Universit├Ątsaugenkliniken D-45122 Essen1,
D-12220 FU Berlin Benjamin Franklin2 ,
D-74076 T├╝bingen3

Supported by Deutsche Forschungsgemeinschaft (DFG), grant Ju 1-1