Abstract
Purpose:
To evaluate intraocular pressure (IOP), retrobulbar blood flow (RBF) parameters and ocular side effects with use of topical dorzolamide/timolol fixed combination (DTFC) drop vs nebulized DTFC mist in primary open-angle glaucoma (POAG) patients.
Methods:
15 POAG patients were included in a prospective, open-label, cross-over study. RBF was measured using Color Doppler imaging in the ophthalmic (OA) and central retinal (CRA) arteries, assessing peak-systolic (PSV) and end-diastolic (EDV) velocities and calculated resistance index (RI). After baseline timolol measurements (IOP and RBF), patients were randomly assigned for the application of DTFC drops or mist for the first treatment and were crossed-over to the alternative formulation on the second visit. DTFC mist/drops were applied to the experimental eye and examinations were performed after 15 and 60 min. DTFC mist was applied 6 times for 30 sec using a misting device. The level of significance p<0.05 was considered significant.
Results:
DTFC mist significantly increased PSVand EDV after 15 and 60 min in both arteries (respectively , OA: PSV 12.5% and 9.6% (p=0.01), EDV 25.8% and 23.1% (p=0.03); CRA: PSV 11.5% and 8.7% (p<0.05); EDV 32% and 21.6% (p<0.02)). DTFC drops had similar effects on CRA PSV and EDV after 15 min and 60 min (respectively, PSV 8.1% and 9.6% (p<0.02); EDV 17.1% and 23% (p<0.03)) but a statistically significant effect in OA PSV and EDV was seen only after 15 min (9% and 21.4%, p<0.02). DTFC mist reduced CRA RI after both time points (8.5% and 10.2%, p<0.04). Both formulations showed significant decreases in IOP after 15 and 60 min With IOP decreasing by 5.7% (p=0.01) after 15 min and 10.2% (p=0.002) after 60 min using DTFC mist, and by 4% (p=0.01) and 9.3% (p<0.001) after using DTFC drops. All patients reported ocular irritation after drop application and 1 patient complained of general weakness after mist treatment.
Conclusions:
Mist of nebulized DTFC reduced IOP and increased blood flow in the OA and the CRA, without causing ocular irritation as compared to traditional DTFC drop methodology.
Keywords: 568 intraocular pressure •
436 blood supply •
443 carbonic anhydrase