The Effect of Cosopt Therapy on Ocular Hemodynamics in Primary Open Angle Glaucoma

Abstract

Abstract: : Purpose: To assess the effect of Cosopt and Xalatan on choroidal and retinal blood flow in patients with primary open angle glaucoma (POAG) Methods: All procedures were approved by an IRB, and informed consent was obtained. Sixteen patients with POAG (63.5 ± 10.8 years, 9 male, 7 female) were recruited for this double blind randomized cross–over study. All patients received a 2 week run in of timolol BID before baseline measurements were taken. Patients were treated with Cosopt BID or Xalatan QD and timolol BID for 4 weeks. After 4 weeks, patients were placed on a 2 week treatment washout and returned for a second baseline exam followed by the other treatment. Blood flow velocites were assessed at baseline and 4 weeks post drug using Color Doppler Imaging (CDI technology Siemens Quantum, Inc., Issaquah WA. Indocyanine green (ICG) angiography was also attained using a Rodenstock scanning laser ophthalmoscope (SLO 101, Germany). The recorded angiograms were analyzed using a digital image analysis system where six 63x63 pixel areas, two peripapillary and four perifoveal, were selected for measurement. Brightness was plotted over time to quantify choroidal hemodynamics. Student’s t–test was used to assess the effects of Cosopt over baseline and Cosopt versus Xalatan. Results: In POAG patients treated with Cosopt, blood flow was significantly improved over baseline in the temporal PCA (TPCA) and CRA measured by CDI. EDV and PSV were improved in the TPCA with Cosopt (p=0.024 and 0.013, respectively.) CRA EDV increased over baseline (p=0.017) and RI decreased (p=0.028). No significant changes in blood flow parameters were demonstrated with Xalatan. Cosopt treatment also improved choroidal hemodynamics measured by ICG in POAG patients when compared to treatment with Xalatan. Fifteen of 16 ICG measurement parameters, indicating increased choroidal flow, were statistically significant with p values ranging from 0.002 to 0.034. Conclusions: Cosopt significantly increases retrobulbar and retinal blood flow in POAG patients. Choroidal hemodynamics in patients treated with Cosopt were significantly hastened compared to treatment with Xalatan.

Keywords: blood supply • pharmacology • clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials