THE EFFECT OF 0.5-PERCENT TIMOLOL MALEATE ON THE OCULAR PERFUSION OF OCULAR HYPERTENSIVE PATIENTS BY SCANNING LASER FLOWMETRY

To understand the effect of 0.5% timolol maleate on the ocular perfusi on of the optic disc and macula in ocular hypertensive patients, we en rolled 10 males and 15 females without any systemic or ocular disease, except intraocular pressure higher than 20 mmHg. Their average age wa s 33 +/- 13 y/o (range 14-45). Under the randomized, double-masked des ign, one drop of 0.5% timolol maleate was given in one eye, and placeb o in the fellow eye. Heart rate, blood pressure, intraocular pressure, and ocular perfusion were measured at baseline, and then 30 minutes a nd 2 hours after treatment. Ocular perfusion was measured by Heidelber g Retina Flowmeter (Heidelberg Engineering GmbH, Heidelberg, Germany). We used 10 degree measurement field and 10x10 pixels measurement fram e. Four areas were measured, i.e., temporal upper, temporal lower, and nasal parts of the optic disc, and macula. In comparison to the basel ine, the treated eyes had a slight reduction of blood flow, volume, an d velocity 30 minutes after treatment, but these parameters came back close to the baseline value at 2 hours after treatment. Similar change s were also noted in the control eyes. The results showed that a singl e drop of 0.5% timolol had minimal effects on the retinal and macular circulation within 2 hours after treatment.