Reduced oscillatory potentials of the full-field electroretinogram of eyes with aphakic or pseudophakic cystoid macular edema

Abstract

Purpose To report reduced oscillatory potentials (OPs) in the full-field electroretinogram (ERG) of eyes with aphakic or pseudophakic cystoid macular edema (CME). Design Observational case series. Methods Bright white flash full–field ERGs were recorded from 19 eyes of 19 patients (ages, 53–84 years) with aphakic or pseudophakic CME. Seven of the cases had uncomplicated phacoemulsification (PE) with implantation of a posterior chamber intraocular lens (PC-IOL) and 6 had posterior capsular rupture during phacoemulsification and aspiration with implantation of a PC-IOL. Four additional patients had uncomplicated intracapsular cataract extraction (ICCE), and 2 had secondary anterior chamber intraocular lens after ICCE. Their fellow eyes without CME served as controls. Cystoid macular edema was diagnosed as clinically significant by slit-lamp examination and by fluorescein angiography. The grading for severity of CME was based on the fluorescein angiography. The visual acuity ranged from 20/200 to 20/16. Results There were no significant differences in the mean amplitudes and implicit times of the a-waves and b-waves between the affected eyes and the fellow eyes. The mean summed amplitude of the OPs was significantly reduced in the affected eyes ( P = .0003, Wilcoxon signed rank test). This decrease was strongly correlated with visual acuity (r = .779, P < .0001). The mean implicit time of the first OP was significantly delayed in the affected eyes ( P = .0089, Wilcoxon signed rank test). Conclusions Because the peripheral retina contributes more significantly to full-field ERGs than the macula, the reduced OP amplitudes of the full-field ERGs in eyes with aphakic or pseudophakic CME suggest a functional impairment not only in the macula but also throughout the retina.