NCT00957190: DIOXXACT

Change in Optic Nerve Head Blood Flow,Optic Nerve Topography and Diurnal Fluctuation of Intraocular Pressure and Pulsatile Ocular Blood Flow in Glaucoma:Cosopt and Xalatan vs Xalatan Alone

Completed Phase 4 Last updated 23 March 2017

What this trial tests

Phase 4 trial testing Dorzolamide 20 mg and Timolol 5 mg in Eye Disease in 25 participants. Completed in 1 February 2012.

Timeline

4 May 2009

Primary endpoint
14 September 2011

1 February 2012

Quick facts

Lead sponsor	Maisonneuve-Rosemont Hospital
Phase	Phase 4
Status	Completed
Study type	INTERVENTIONAL
Allocation	na
Design	single group
Masking	none
Primary purpose	other
Enrollment	25
Start date	4 May 2009
Primary completion	14 September 2011
Estimated completion	1 February 2012
Sites	1 location across Canada

Drugs / interventions tested

• Dorzolamide 20 mg and Timolol 5 mg — full drug profile →

Conditions studied

• Eye Disease — all drugs for Eye Disease →

Sponsor

Maisonneuve-Rosemont Hospital

Who can join

Adults 30 to 80, any sex, with Eye Disease. Patients with the condition only — healthy volunteers not accepted.

What's being measured

Primary outcomes are the specific endpoints the trial is designed to prove or disprove.

• Clinical evidence for lower diurnal variational Intraocular Pressure
  Time frame: Six weeks

Sponsor's own description

Diurnal and intervisit fluctuations in IOP are strongly associated with progression of open angle glaucoma and therefore need to be minimized. Control of diurnal fluctuations of IOP with different ocular hypotensive medications has been studied in some detail. But how do IOP changes contribute to progressive glaucomatous optic nerve damage? It is reasonable to assume that there are two principal effects of IOP changes. First, IOP fluctuations result in changes in the stresses and strains on the ONH which in turn result in morphological changes to the ONH. These morphological changes could in turn result in stretching and damage to axons of the ONH. Secondly, IOP fluctuations results in changes to the forces acting on the ONH vasculature, leading to changes in ONH vascular perfusion. These changes to perfusion could in turn result in relative ischemia of the ONH and consequent ONH damage.

The investigators propose to monitor diurnal fluctuations in IOP and choroidal blood flow (Pulsatile Ocular Blood Flow,POBF), and intervisit ONH topographical and blood flow changes-ie to monitor the direct ONH consequences of IOP . Open angle glaucoma patients are commonly prescribed topical latanoprost as first line therapy. The EXACCT study, for which I was the principal investigator and which is now submitted for publication, demonstrated that COSOPT was an efficacious choice as second line therapy for patients not controlled on latanoprost monotherapy. The investigators will therefore recruit 20 OAG patients on latanoprost monotherapy, perform diurnal curves of IOP, as well as a.m. ONH morphology and ONH blood flow. Cosopt will then be added and at the next visit the same measurements will be repeated.

The investigators expect that when Cosopt is added the investigators will demonstrate improved IOP, morphology and blood flow compared to the latanoprost baseline. Furthermore the investigators expect the the diurnal fluctuation of IOP and choroidal blood flow will be stabilized on Cosopt therapy. The implications are that adding Cosopt to latanoprost can stabilize not only the IOP but also the damaging consequences of IOP to the optic nerve head.

Publications & conference data

No peer-reviewed publications indexed yet for this trial. Completed trials usually publish results within 12-18 months.