IBOPAMINE d-1 dopaminergic agonist in the physiopathology of intraocular pressure

Ibopamine as eyedrops, following adminis-tration in the conjunctival sac, is readily hy-drolysed to epinine, a dopamine analogue, by the esterases present in the aqueous hu¬mour and in the ocular tissues. lbopamine stimulates a-adrenergic recep¬tors and D-l dopaminergic receptors at ocu¬lar level. The non-cycloplegic mydriatic effect of ibopamine is due to an a-adrenergic stimu¬lation, while the D-l dopaminergic activity determines an increase in aqueous humour production. lbopamine induces a marked short-term non-cycloplegic mydriasis, lacking both top¬ical and systemic undesireble side-effects, , which enables its use in the diagnostic exam-ination of the ocular fundus, particularly in the newborn and pediatric patients. lbopamine may be employed to substitute phenylephrine in the association with tropi¬camide and/ or cyclopentolate; moreover it proves to be effective as a mydriatic prior to and after surgical procedures. The D-l dopaminergic activity of ibopamine represents the more interesting property of the drug under different aspects: in the diag¬nosis of glaucoma, in the treatment of ocular hypotony and in studies on the physiopathol¬ogy of the intraocular pressure. Several clin¬ical investigations confirmed the usefulness of ibopamine in the diagnostic iter of glau¬coma as a pharmacological test to evaluate the functionality of the outflow pathways of the aqueous humour. The test is simple to perform; positive in 92% of patients suffer¬ing from open-angle glaucoma, while it is negative in the healthy eye. lts use is recom¬mended in relatives of glaucomatous pa¬tients. The increase in aqueous humour production induced by ibopamine proves to be very use¬ful in the treatment of ocular hypotony fol¬lowing vitreo-retinal or antiglaucomatous filtering surgery and in the treatment in chronic hypotony secondary to long-lasting uveitis.