DOPPLER ULTRASONOGRAPHY OF THE CENTRAL RETINAL ARTERY IN NORMALS TREATED WITH TOPICAL TIMOLOL

Using high-resolution Duplex scanning it is possible to evaluate the b lood flow velocity in the central retinal artery of eyes of normal ind ividuals. The flow velocity can be divided into its systolic and diast olic phases. Topical timolol maleate 0.5%, a non-selective beta-adrene rgic receptor blocking agent, was then administered to one eye in each of the normals and the flow velocity was again recorded. The flow vel ocity improvement was significant, with a 43.58% increase in the systo lic phase and a 61.53% increase in the diastolic phase. The diastolic component increased from 49.29% to 55.56%. The increased flow velocity may be due to a vasodilatory effect of timolol. The technique is brie fly described and the significance of the results discussed.