Effects of Smoothing and Adaptive Filtering in Multifocal Electroretinography (mfERG)

(1) Background: mfERG testing is used to study the function of cone photoreceptors in the central retina. Various filters including “smoothing” (Smooth) and “adaptive data filtering” (Adapt) are used to simplify raw data. This study will seek to characterize the effect of data modification on raw patient data. (2) Methods: This was a retrospective study of patients with mfERG results at our institution. For each patient, raw mfERG data without filtering, with smooth level 4 modifier applied, and with adapt level 4 applied were collected and compared. (4) Conclusions: In all patients, smoothing and adaptive filter modifiers create statistically significant differences in both P1 latency and P1 amplitude values when compared to raw data. The impacts of these filters demonstrated in this study should impact physicians’ decision making when interpreting mfERG results.