[Changes in global ERG in Birdshot chorioretinopathy and correlation with central macular thickness on OCT]

To describe the characteristics of electroretinograms (ERGs) of a series of patients with Birdshot Chorioretinopathy (BSCR) at various stages and evaluate the correlation between ERG abnormalities and central macular thickness measured on Optical Coherence Tomography (OCT).

This was a retrospective study of 20 eyes of 10 patients who underwent both a global ERG according to the International society for clinical electrophysiology of vision (ISCEV) protocol and simultaneous macular OCT with measurement of central macular thickness (CMT).

Five eyes had non-discernible ERGs. In the other fifteen eyes, the following abnormalities were found: decreased amplitude of the scotopic (DA 0.01, DA 3.0, and DA 10.0) and photopic (LA 3.0) b-waves, increased implicit time of photopic b-wave (LA 3.0), and changes in oscillatory potentials. After adjusting for age and gender, CMT measured by OCT was correlated with implicit times of the b-wave at LA 3.0 (-0.862; P=0.08) and Flicker 30Hz period (-0.883; P=0.08). No scotopic ERG parameter was correlated with CMT.

Retinal electrogenesis is altered in BSCR. There is a correlation between central macular thickness and Flicker 30Hz period and implicit time of b-wave at DA 3.0, as demonstrated by our study. Therefore, OCT can reflect progressive involvement in BSCR and can be a complementary examination to ERG.