97th DOG Annual Meeting 1999
DIAGNOSIS CLARIFICATION OF RETINITIS PIGMENTOSA (RP) WITH THE HELP OF THE MULTIFOCAL ERG (MF-ERG) - A CASE REPORT
A. Palmowski, W. Eich
Introduction: Generalized retinal degenerations, such as retinitis pigmentosa, may initially manifest with focal retinal dysfunctions. These may only be detected with new electrophysiological examination techniques, such as the MF-ERG.
Case report: Mother and daughter, 81 and 46 years of age, showed bilateral caudal bone-spiculae formations with corresponding cranial visual field defects in the static perimetry of the central visual field (Octopus) and in the kinetic perimetry (Goldmann) as well as a pathologic nyctometry with good visual acuity (20/20).
Results: Pattern-VEP, Pattern-ERG, EOG and cone ERG were within the normal range, the scotopic ERG showed reduced amplitudes. The multifocal cone ERG (VERIS scientific 4.0 TM) of the central 50 degrees showed reduced amplitudes and prolonged latencies in the first order responce component. These findings were more pronounced in the area of the bone spiculae and the corresponding scotomta. The cranial responses were averaged together and compared to those of the caudal half. The latency of P1 (= 1st positive peak) lay between 30,8 ms (min) and 45.0 ms (max) in the cranial half and between 28,3 ms (min) and 35,8ms (max) in the caudal half. For N2 (= 2nd negative peak) the corresponding latencies were: 47,5 ms (min) - 64,1 ms (max) cranial response, and 43,3 ms (min) - 50.8 ms (max) caudal response. The cranial amplitude N1-P1 was between 3,3-6,8 nV/deg.2 (min-max), the caudal amplitude N1-P1 was between 10,8-12,5 nV/deg.2 (min-max).
Conclusion: The MF-ERG enables the detection of focal retinal cone dysfunction of different severity in retinitis pigmentosa 1,2. It is an additional tool that may aid the diagnosis of this disease.
1 Hood-DC; Holopigian-K; Greenstein-V; Seiple-W; Li-J; Sutter-EE; Carr-RE
(1998) Assessment of local retinal function in patients with retinitis
pigmentosa using the multi-focal ERG technique. Vision-Res. 1998 Jan; 38(1):
2 Seeliger-M; Kretschmann-U; Apfelstedt-Sylla-E; Ruther-K; Zrenner-E (1998)
Multifocal Electroretinography in Retinitis Pigmentosa. Am J Ophthalmol