Ocular blood flow in the retina, choroid and optic nerve head should be measured in addition to the intraocular pressure (IOP) in order to better diagnose glaucoma disease and to better evaluate the efficacy of antiglaucoma drugs. It was found that beta-adrenergic blockers, the most widely used antiglaucoma drugs, reduced ocular blood flow in animals and worsened glaucoma disease in some patients, even though the IOP was reduced to the normal range. Therefore, their use for glaucoma treatment requires careful re-evaluation. On the other hand, most dopamine antagonists were found to reduce the IOP and increase the blood flow to the retina, choroid, iris and ciliary muscle. Therefore, these agents could be used for glaucoma treatment. Further, dopamine antagonists were found to improve retinal function after ischemia and, thus, also could be used for the treatment of ischemic retinopathy.