A treatment regimen which is individually tailored to the individual patient's needs should be developed by the attending physician and the achievement of the set objectives should be monitored at regular intervals. However, restrictions induced by patients due to inadequate adherence or by the drug due to limited efficacy of the drug have to be considered. Therefore, eye drop therapy in open-angle glaucoma is not always sufficient. It should be supplemented in due time by laser or filtering surgery before the affected patients and their optic nerves suffer advanced glaucomatous damage.