Abstract

SO.08.05

Anti-VEGF therapy – chances and risks

Ziemssen F., Peters S., Heiduschka P., Grisanti S., Schraermeyer U., Bartz-Schmidt K. U.
University Eye Hospital Tuebingen

Vascular endothelial growth factor (VEGF) plays a pivotal role angiogenesis. Regulating haemodynamics, (lymphoid-) vessel architecture, haematopoesis and immune system, endocrinology and reparative processes, inhibition of VEGF can cause multiple adverse events. Previous data let suggest that – even after intravitreal injection – systemic exposure might occur bearing the risk of manifest side effects. Growing experience with intravenous administration of the antibody bevacizumab (Avastin^®) pointed at the potential consequences of an all-isoform-blockade. The change of haemodynamic parameters implies a direct influence on patient’s morbidity. Studies, already conducted before and during the approval process, do not provide sufficient statistical power when evaluating, whether systemic events significantly differ between treatment and control group.
The regulation of retinal perfusion causes an altered vasal tone following anti-VEGF treatment. Physiologic fenestration of choroicapillaris is significantly reduced after inhibition of VEGF. Possible effects on the local oxygen supply in ischaemic tissue and induction of recurrent proliferations in neovascular age-related macular degeneration have to be considered.
In contrast to destructing treatment modalities (laser, cryo), VEGF-inhibitors promise fast response of retinal neovascularizations and preservation of better function (visual fields). Maturation of growing vessels (pericytes) and secondary formation of membranes are limiting the timepoint, until anti-VEGF therapy is most effective. A diligent use of available drugs has to respect, which types of exudative retinopathy are showing no or only very limited response to anti-VEGF treatment.

Copyright: Porstmann Kongresse GmbH. All rights reserved. Impressum, Disclaimer.