Ocular pulse amplitude, intraocular pressure and beta-blocker/carbonic anhydrase combination therapy

Background Beyond intraocular pressure (IOP, German abbreviation: IOD) ocul ar perfusion is increasingly discussed in the pathogenesis of the glaucomas . The present study was designed to investigate for ocular pulse amplitude (OPA) in primary open angle glaucoma patients with elevated intraocular pre ssure (POAG, German abbreviation: POWG) following application of timolol, a beta-blocker and dorzolamide a topical carbonic anhydrase inhibitor. Methods OPA (Ocular Blood Flow System, OBF Labs U.K.) IOP, heart rate, syst olic and diastolic brachial artery pressures were measured before and 4 wee ks following application of timolol and additional 4 weeks following applic ation of a timolol/dorzolamide combination in 14 POAG patients. Results Following administration of timolol, IOP was highly significantly r educed in drug treated POAG eyes; this effect was additively enhanced by do rzolamide. Timolol did not affect OPA, whereas dorzolamide significantly in creased OPA in drug treated POAG eyes. Systemic perfusion parameters were u nchanged. Conclusion Timolol and dorzolamide drastically reduced IOP, in addition dor zolamide increased OPA in POAG, an ocular microcirculatory effect which may further help to improve prognosis of POAG.