Comparing Efficacy of XalacomTM and CosoptTM on Intraocular Pressure and Optic Nerve Head Perfusion in Glaucoma Patients: A Randomized Cross–Over Trial

Abstract

 

Abstract:

 

Blood flow may play a major role in the development of open angle glaucoma. It is important to know the effect of a drug on intraocular pressure (IOP) and peripapillary retinal perfusion used in the treatment of the disease. The aim of this study was to compare the effects of Xalacom^TM (q.d.) and Cosopt^TM (bid.) on intraocular hemodynamics and IOP in glaucoma patients and ocular hypertensives.

 

 

Following a 3 weeks run–in period with timolol 0.5% bid (baseline), patients were randomly assigned to Cosopt^TM b.i.d. administered at 8.00 and 20.00 hours in group I and Xalacom^TM q.d. at 8.00 hours in group II. After 6 weeks all patients continued with the other medication for another 6 weeks. Measurements included visual acuity, slit–lamp examination, retinal blood flow with the Heidelberg Retina Flowmeter (HRF) using the standard measurement window and IOP. Data from paired eyes were averaged.

 

We included 30 eyes of 16 patients (8 females, 8 males; mean age: 64.7 ± 8.5 years).

 

 

^{*I: Cosopt–Xalacom; II: Xalacom–Cosopt}

 

Analysis of covariance revealed a statistically significant (p=0.003) difference of mean IOP reduction in favor of Xalacom^TM q.d. treatment. The difference of mean retinal blood flow reduction was only borderline statistically significant (p=0.057). We found tendencies of retinal blood flow reduction from Cosopt^TM b.i.d. (p=0.156) and slight increase from Xalacom^TM q.d. (p=0.395).

 

The study results suggest a retinal blood flow reduction following fixed combination treatment with Cosopt^TM after pre–treatment with timolol 0.5% b.i.d. for 3 weeks. The HRF data do not reveal a significant increase of retinal blood flow from Xalacom^TM eye drops. The significantly better IOP reduction from Xalacom^TM treatment was confirmed.

 

 

Keywords: optic flow • optic disc • pharmacology