Electroretinogram and Visual Field Correlation in Birdshot Chorioretinopathy

Purpose: The aim of this study was to assess possible correlation between the visual field and electroretinogram (ERG) parameters in birdshot choriorctinopathy (BCR). Design: Retrospective cross-sectional study. Methods: This single-center study included 21 eyes of 11 patients with BCR with prior ERG and Goldmann kinetic perimetry. Generalized estimating equation was used for statistical analysis, and isopters V4e and I4e were modeled as separate outcomes with each parameter of ERG as the main independent variable. The main outcome measure was presence or absence of correlation between the Goldmann isopters and ERG parameters including the amplitudes and implicit times of dark adapted (DA) and light adapted (LA) a-waves and b-waves (DA 0.01, DA 3.0, DA 10.0, and LA 3.0) and LA 30 Hz. Results: There was a strong positive correlation between the size of isopter V4e and all the scotopic and photopic standard ERG amplitudes [P < 0.0001 for all, except LA 3.0 a-wave (P = 0.0019) and LA 30 Hz (P = 0.0026)]. For the implicit times, only DA 3.0 a-wave (P = 0.007) and LA 30 Hz (P < 0.0001) showed significant negative correlations. There were no correlations between the size of isopter I4e and any ERG amplitudes; however, 3 implicit times showed some negative correlation: DA 3.0 a-wave (P < 0.0001), DA 10.0 b-wave (P= 0.0251), and LA 3.0 b-wave (P < 0.0001). Conclusions: In this study, the largest isopter of Glodmann visual field showed a strong positive correlation with all standard ERG amplitudes in BCR. This novel finding underscores the role of ERG as an objective visual function test in monitoring the disease activity.

Automated summary

In this study, a strong positive correlation was found between the largest isopter of Glodmann visual field and all standard ERG amplitudes in birdshot choriorctinopathy (BCR) patients. This novel finding highlights the role of ERG as an objective visual function test in monitoring disease activity.