The Effect of Fluorescein Angiography on Full-Field Electroretinography Parameters

PURPOSE To investigate the effect of simultaneously performed fluorescein angiography (FA) on full-field electroretinography (ffERG) parameters. METHOD Scotopic and photopic ffERG were performed immediately and 60 minutes after conventional FA in patients with retinal photoreceptor disorders; a-and b-wave amplitudes were compared between recordings obtained at the two time intervals in each patient. RESULTS Ten eyes of five (3 male and 2 female) patients with mean age of 19.6±3.8 (range, 15-25) years were studied. Intravenous fluorescein administration caused an immediate reduction in ERG waves which was most prominent in rod and maximal combined responses. Mean a-wave amplitude in maximal combined response, rod response and cone response ERGs was 46.0±18.8, 8.0±7.0 and 5.1±2.0 mv immediately after FA which was increased to 79.0±30.0, 21.5± 22.5 and 6.5±2.4 mv 60 minutes afterwards, respectively (P<0.005 for all comparisons). Mean b-wave amplitude in the same order was 91.0±17.5, 47.7±17.2 and 17.3±14.7mv which was increased to 145.0±54.3, 91.8±48.1 and 20.0±17.7 mv respectively, 60 minutes after FA (P<0.005 for all comparisons). CONCLUSION The amplitude of ERG a- and b-waves under scotopic and photopic conditions increased significantly one hour after FA. These changes may be explained by disappearance of phototoxic and bleaching effects of strong light exposure from the light source of the angiography machine and fluorescein molecule on retinal photoreceptors.