The combination of guanethidine 3% and adrenaline 0.5% in 1 eyedrop (GA) in glaucoma treatment.

During a 7-month period 33 patients (20 with primary open-angle glaucoma and 13 with suspected glaucoma) were treated with guanethidine 3% and adrenaline 0.5% in 1 eyedrop twice daily. The previous therapy was discontinued and the aim of the trial was to treat the patients with GA alone. There was an average decrease in intraocular pressure of 10.8 mmHg or 37.5% for the whole group (including 5 patients with additional therapy). In eyes with an average IOP in a day-curve without medication equal to or higher than 28 mmHg we found a decrease of 44.6% or 14.4 mmHg, and in eyes with an average IOP without medication between 21 and 28 mmHg a decrease of 30.4% or 7.6 mmHg. With GA alone the IOP was 3.3 to 3.9 mmHg lower than on the previous therapy (P less than 0.05); 46% of the eyes without additional therapy had all IOPs lower than 22 mmHg and 74% of the eyes had IOPs lower than 22 mmHg except 1 with a peak lower or equal to 25 mmHg 3 hours after application. This peak 3 hours after application indicates that GA has a biphasic action and was significant at the 0.5% level. Red eyes and slight ptosis were no problem for most patients. Patients found it very convenient to administer GA only twice daily.