Purpose: Generalized retinal degenerations such as retinitis pigmentosa may manifest with focal retinal dysfunctions. These may be detected objectively by new electrophysiological techniques, such as multifocal electroretinography (ERG).
Case report: A mother and daughter, aged 81 and 46 years, 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).
Results: Pattern VEP, pattern ERG, EOG, and cone ERG were within the normal range. The scotopic ERG was in the lower normal range. The multifocal cone ERG of the central 50 degrees showed reduced amplitudes and prolonged latencies in the first-order response component. These findings corresponded to the area of the bone spiculae and the scotomata.
Conclusion: Multifocal ERG enables the detection of focal retinal cone dysfunction in segmental retinitis pigmentosa. It is an additional tool that may aid in the diagnosis and classification of this disease.