PURPOSE: To evaluate the changes in focal macular electroretinograms (fmERGs) after surgical removal of choroidal neovascular (CNV) lesions. METHODS: Fourteen patients (14 eyes) with subfoveal or juxtafoveal CNV associated with age-related macular degeneration and 1 patient with idiopathic CNV underwent vitrectomy and removal of the lesions. fmERGs elicited by a 15 degree stimulus were recorded before and 3 months after surgery. Optical coherence tomography (OCT) was performed to measure the foveal and parafoveal thickness before and 3 months after surgery. RESULTS: Preoperative fmERGs were markedly reduced in all eyes. The mean amplitude of the b-wave in 15 eyes recorded 3 months after surgery increased significantly (P = 0.0022, Wilcoxon signed rank test). In all eyes except two with nearly nonrecordable a- and b- waves, the mean b-wave-to-a-wave ratio after surgery increased significantly in all eyes (P = 0.0330, Wilcoxon signed rank test). The percentage increase in the b-wave amplitude correlated significantly with the percentage decrease in the mean parafoveal retinal thickness (r = 0.688, P = 0.0076). CONCLUSIONS: The decreased macular ERGs were partially recoverable in the early postoperative period. The decreased retinal edema after surgery may have contributed to this recovery.
PURPOSE: To evaluate the changes in focal macular electroretinograms (fmERGs) after surgical removal of choroidal neovascular (CNV) lesions. METHODS: Fourteen patients (14 eyes) with subfoveal or juxtafoveal CNV associated with age-related macular degeneration and 1 patient with idiopathic CNV underwent vitrectomy and removal of the lesions. fmERGs elicited by a 15 degree stimulus were recorded before and 3 months after surgery. Optical coherence tomography (OCT) was performed to measure the foveal and parafoveal thickness before and 3 months after surgery. RESULTS: Preoperative fmERGs were markedly reduced in all eyes. The mean amplitude of the b-wave in 15 eyes recorded 3 months after surgery increased significantly (P = 0.0022, Wilcoxon signed rank test). In all eyes except two with nearly nonrecordable a- and b- waves, the mean b-wave-to-a-wave ratio after surgery increased significantly in all eyes (P = 0.0330, Wilcoxon signed rank test). The percentage increase in the b-wave amplitude correlated significantly with the percentage decrease in the mean parafoveal retinal thickness (r = 0.688, P = 0.0076). CONCLUSIONS: The decreased macular ERGs were partially recoverable in the early postoperative period. The decreased retinal edema after surgery may have contributed to this recovery.