Use of ibopamine as provocative test in glaucoma diagnostics

Purpose. Ibopamine is a new drug with mydriatic properties without cycloplegia. Ibopamine induces no increase of IOP in healthy eyes but in patients with POAG it provokes an increase of IOP in a high precentage of eyes (92%). In view of such properties Ibopamine was proposed as provocative test in the diagnostic iter of glaucoma. The present paper describes our last results about these findings. Methods. We performed an Ibopamine provocative test in 2 groups of subjects: 1) 163 healthy normotensive volunteers (326 eyes); 2)175 patients with POAG (250 eyes). In 80 patients (40 healthy volunteers and 40 POAG patients) the test was repeated after pretreatement with an alpha-blocker (thymoxamine) to evaluate the influence of mydriasis on the hypertensive response. Results. No IOP increase over 2 mmHg were ever observed in healthy volunteers (mean changes -0.9 mmHg SD1.88). In POAG patients we noticed an increase greater than 3 mmHg in 90% (224 eyes) of the examined eyes (mean increase 7.8 mmHg SD 4.2). The pretreatment with thymoxamine did not modify significantly the hypertensive response to Ibopamine. Conclusions. We believe that ibopamine could be useful as provocative test for the identification of subjects in danger of developing glaucoma: actually our study in progress and not yet published are going to confirm such hypothesis.