Comparison of different high resolution multifocal electroretinogram recordings in patients with age-related maculopathy

Aim: to compare two different resolutions of multifocal electroretinogram r ecordings (MF-ERG) in patients with age-related macular degeneration (AMD). Patients and methods: in 20 eyes (14 patients) with early or late stages o f AMD, MF-ERGs of 8 min duration were recorded using a low and a high resol ution. The central 50 degrees of the retina were stimulated by 103 as well as by 241 stimulus elements. Results were compared with one another and wit h an age-matched control group. Results: when response averages of equal ec centricity were analysed, amplitudes of the MF-ERG differed significantly f rom normal within the central 40 degrees. This held true for both low (103) and high (241) resolutions. Sixteen of 20 eyes also showed focal retinal d ysfunction at both resolutions. In one case, the high resolution MF-ERGs co uld detect functional deficits that could not be seen with the lower resolu tion. However, due to a reduced signal-to-noise ratio three high resolution recordings could not be analysed. Conclusion: high resolution MF-ERG seems more sensitive than low resolution MF-ERG. However, the low resolution (10 3) MF-ERG is recommended for routine application in the clinic because of i ts better signal-to-noise ratio.