[Eye Drops Instead of Intravitreal Injections? The Dream of Treating Macular Diseases by Topically Administered Drugs].Klin Monbl Augenheilkd 2017; 234(9):1088-1093KM
Background The introduction of VEGF inhibitors revolutionized treatment for age-related macular degeneration. However, it requires regular intravitreal (IVT) injections. Hence, replacement of IVT injections by topical, non-invasive eye drop treatment is subject to intensive research. Material and Methods Literature and database research on topical therapies for neovascular AMD. Results Several clinical projects with topical inhibitors of the VEGF pathway were initiated recently. Several candidate molecules were investigated and should have an efficacy potential in neovascular AMD given their ability to block the VEGF pathway. Preclinical experiments were quite promising. Still, translation into the clinical application has not been successful thus far. Differences in preclinical and clinical pharmacokinetics are assumed to be the major barrier to successful translation. In addition, specific algorithms for monitoring of disease activity are required for successful clinical implementation; otherwise, a topical therapy may reduce the IVT injection number, but patients would not gain independence through fewer office visits. Discussion It is required to refine the scientific basis including preclinical models and screening cascades. This will enable targeted selection of future candidates for clinical development.