Clinical trial NCT00991822: A Comparison of the Effect of Dorzolamide and Timolol on Optic Disk Blood Flow in Patients With Open Angle Glaucoma
Official title: A Double-masked Comparison of the Effect of Dorzolamide and Timolol on Optic Disk Blood Flow in Patients With Open Angle Glaucoma
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: PHASE2
PHASE3
Conditions: Glaucoma, Open-Angle
Keywords: open angle glaucoma
timolol
dorzolamide
Lead sponsor: Medical University of Vienna
Sponsor class: OTHER
First posted: 2009-10-08
Enrollment: 160
Sex: ALL
Minimum age (years): 19
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: BASIC_SCIENCE

Brief summary: Glaucoma is one of the most common causes of blindness in the industrialized nations. For a long time glaucoma has been defined as a disease in which high intraocular pressure (IOP) leads to irreversible optic disk damage and concommitant visual field loss. However, recent investigations show that IOP is not necessarily an adequate measure of clinical severity or a predictor of clinical progression: about 20% of all eyes with high IOP do not develop visual field loss and some patients suffering from visual field loss due to optic disk damage have normal IOP. Hence, factors other than IOP are likely involved in the pathogenesis of glaucoma. The role of vascular factors in the pathogenesis of glaucoma has recently received much attention and optic nerve head hypoperfusion may play a critical role in the development of glaucoma. It may therefore be important for an optimal prevention of visual field defects in glaucoma that the topical antiglaucoma drugs used do not only reduce IOP but also stabilize or enhance the perfusion of the optic nerve head.

Therefore, the aim of the present study is to compare the effect of a 3 months treatment with timolol or dorzolamide in patients with open angle glaucoma on optic disk blood flow.


Eligibility criteria: Inclusion Criteria:

* Men and women older than 19 years
* Primary open angle glaucoma or ocular hypertension with IOP higher than 22 mmHg in at least one eye
* Washout period for previous antiglaucoma treatment: two weeks for adrenergic agonists, one week for parasympathomimetic agents

Exclusion Criteria:

* Exfoliation glaucoma, pigmentary glaucoma
* History of acute angle closure
* Intraocular surgery or argon laser trabeculoplasty within the last 6 months
* Ocular inflammation or infection within the last 3 months
* Contact lenses
* Patients with bradycardia (heart rate less than 50 beats/min)
* Second or third degree heart block
* Asthma
* COPD
* Congestive Heart Failure
* Severe renal impairment (Creatinine clearance less than 1.8 l/h
* History or hypersensitivity to one of the study drugs or drugs with similar chemical structure
* History of non-IOP responder to beta-blockers or carbonic anhydrase inhibitors
* Pregnancy

Primary outcomes:
measure: Percent change over baseline after 3 months of treatment of optic disk blood flow measured with the Heidelberg Retina Flowmeter
timeFrame: 5 minutes measurement of optic disk blood flow on 3 study days
measure: Percent change over baseline after 3 months of treatment of fundus pulsation amplitude (FPA) in the optic disk as assessed with laser interferometry
timeFrame: 5 minutes measurement of FPA on 3 study days
Secondary outcomes:
Other outcomes:
Locations:
city: Vienna
country: Austria
facility: Department of Clinical Pharmacology, Medical University of Vienna
Study officials:
affiliation: Medical University of Vienna
name: Hans G Eichler, MD, Prof.
role: PRINCIPAL_INVESTIGATOR
References:
citation: Fuchsjager-Mayrl G, Georgopoulos M, Hommer A, Weigert G, Pemp B, Vass C, Garhofer G, Schmetterer L. Effect of dorzolamide and timolol on ocular pressure: blood flow relationship in patients with primary open-angle glaucoma and ocular hypertension. Invest Ophthalmol Vis Sci. 2010 Mar;51(3):1289-96. doi: 10.1167/iovs.09-3827. Epub 2009 Oct 22.