Abstract
Purpose::
This study is an observational case series comparing full field electroretingrams done before and after an intravitreal injection of Bevacizumab previously determined to be the appropriate treatment for a group of patients with exudative age-related macular degeneration. These comparisons provide information regarding the safety of such injections.
Methods::
Six individuals were asked to volunteer for this study after a diagnosis of exudative age-related macular degeneration was made by a retinal specialist and a decision was made to treat one eye with an intravitreal injection of 1.25mg of bevacizumab. Five patients completed pre- and post- injection ERG testing. Participants were 73 to 93 years of age with a mean of 79.8. Only individuals who had not had any previous treatment by intravitreal injection in either eye were included. Standardized best corrected visual acuity using the ETDRS chart was obtained prior to the ERG. 4 to 6 weeks after the injection the standardized acuity and ERG were repeated. ERG testing consisted of a scotopic (-7 to 2.25 log cd-s m-2) and a photopic intensity series and 30 Hz photopic flicker. ERGs were recorded using a thread electrode placed on the cornea. Comparisons were made between the injected eye and the uninjected eye before and after injection.
Results::
The mean letter score for injected eyes was 67.4 before and 72.8 after injection; for fellow eyes the comparable scores were 49.4 before and 51.4 after. No treatment-related changes were observed in the amplitude of the b-wave recorded under scotopic or photopic conditions across the range of intensities tested. The mean b-wave amplitudes were similar 30 Hz implicit time also were unaltered by treatment. The ERGs from all eyes were below the expected amplitude, consistent with widespread retinal disease.
Conclusions::
This case series suggests that there is an improvement in visual acuity and no short-term alteration of retinal function on ERG testing in patients with exudative age-related macular degeneration who have received their first and only intravitreal injection of Bevacizumab.
Keywords: age-related macular degeneration • electroretinography: clinical • drug toxicity/drug effects