Effects of glaucoma medications on the cardiorespiratory and intraocular pressure status of newly diagnosed glaucoma patients

Abstract

Aims. To evaluate the short term cardiovascular, respiratory, and intraocular pressure (IOP) effects of four glaucoma medications in newly diagnosed glaucoma patients. Methods. 141 newly diagnosed glaucoma patients were recruited and underwent a full ocular, cardiovascular, and respiratory examination, including an electrocardiogram (ECG) and spirometry. They were prescribed one of four topical glaucoma medications and reviewed 3 months later. One eye of each patient was randomly chosen for analysis, performed using analysis of variance and the χ2 test. Results. Latanoprost had the greatest mean IOP lowering effect in both the primary open angle glaucoma (POAG) (p = 0.005) and the 'presumed' normal tension glaucoma (NTG) groups (p = 0.33), reducing the IOP by 8.9 mmHg and 4.1 mmHg respectively. Timolol was associated with lowered pulse rates and reductions in the spirometry measurements. 41% of patients using brimonidine complained of systemic side effects and over 55% of patients using betaxolol complained of ocular irritation. 28% of patients required an alteration in their glaucoma management. Conclusions. Latanoprost appears to be a useful primary treatment for glaucoma patients, in view of superior IOP control and a low incidence of local and systemic side effects. Timolol causes a reduction in measurements of respiratory function, a concern in view of the potential subclinical reversible airways disease in the elderly glaucoma population. Brimonidine is associated with substantial, unpredictable systemic side effects and betaxolol causes ocular irritation and weak IOP control. Spirometry is advised in all patients receiving topical β blocker therapy to control their glaucoma.