Abstract
Purpose::
To investigate the retinal toxicity of bevacizumab in co-application with rt-PA, a commercially available recombinant tissue plasminogen activator (rt-PA), and to facilitate a new therapeutic concept in the treatment of massive subretinal haemorrhage caused by neovascular age-related macular degeneration (AMD).
Methods::
Isolated bovine retinas were perfused with an oxygen preincubated nutrient solution. The electroretinogram (ERG) was recorded as a transretinal potential using Ag/AgCl electrodes. Bevacizumab (0.25mg/ml) and rt-PA (20µg/ml) was added to the nutrient solution for 45 min. Thereafter, the retina was reperfused for 60 min with normal nutrient solution. Similarly, the effects of rt-PA (20µg/ml and 60µg/ml) were investigated on the a- and b-wave amplitude. The percentage of a- and b-wave reduction during the application and at the washout was calculated.
Results::
During the application of different concentrations of rt-PA (20µg/ml and 60µg/ml) as well as for the co-application with bevacizumab (0.25mg/ml, 20µg/ml rt-PA) no significant reduction of the a- and b-wave amplitude was observed. During the washout, the ERG-amplitudes remained unchanged.
Conclusions::
The present study suggests that a subretinal injection of 20µg/ml rt-PA in co-application with bevacizumab (0.25mg/ml) for the treatment of massive subretinal haemorrhage seems possible.
Keywords: retina • electroretinography: non-clinical • drug toxicity/drug effects