The objective of the thesis is the development of formulations for intravitreal injection that are targeting the retinal vasculature in posterior segment eye diseases. Due to the isolated structure of the eye, achieving therapeutically effective drug concentrations at the retinal tissues is challenging. The current work aims at improvement of the therapeutic efficacy of intravitreal injections. Two parts can be distinguished. The first part focuses on the prevention of angiogenesis, through the development of sustained release formulations for vasoactive compounds that are able to overcome retinal vascular occlusions. Injectable and biodegradable polymer systems, based on α-hydroxy acids, are investigated as carriers or prodrugs for this application. The second part aims at inhibiting angiogenesis, through the improvement of existing formulations that act against VEGF-A. Therapeutic antibodies are combined with corticosteroids or with small therapeutically inactive excipients. Goal of the former is a stable combo-formulation that might cause a synergistic effect, purpose of the second is to prevent aggregate formation in the antibody formulation.