Validation of Retinal Oximetry in Glaucoma Patients: a Structural and Functional Correlation

Sponsor

Universitaire Ziekenhuizen Leuven (Other)

Overall Status

Completed

CT.gov ID

NCT01391247

Collaborator

(none)

Enrollment

Location

Duration (Months)

5.4

Patients Per Site Per Month

Study Details

Study Description

Brief Summary

Retinal ischemia is thought to play an important role in the pathogenesis of glaucoma. Up until today, very little is known about the metabolic alterations in the retina of glaucoma patients, since only techniques for surrogate measurements of metabolism (like blood flow velocities and vessel diameter) were available. Oximetry has provided us with an important tool to study metabolism in glaucoma, and to correlate these findings with the available blood flow evaluation techniques. Preliminary results by the group of Prof Stefánsson (2011) with the dual wavelength oximeter pointed out that deeper glaucomatous visual field defects are associated with decreased arteriovenous differences in retinal oxygen saturation. These data suggest that a change in oxygen metabolism occurs in glaucomatous retina. This reduced oxygen metabolism may be related to tissue atrophy. However, this explanation is still hypothetical, since the relation between these oximetry results and structural changes in the optic nerve have not been studied yet.

What are the oximetry values in a normal population of within the same age group as the glaucoma population? To answer this question, a normative database of the investigators retinal oximetry device needs to be constructed for healthy controls.
Do glaucoma patients have different retinal oximetry values than these normal patients? Are there any differences in retinal oxygenation between these glaucoma groups? To answer these questions, oximetry measurements will be performed in patients with normal tension glaucoma (NTG) and primary open angle glaucoma (POAG).
Is there an association between structural optic disc and retinal nerve fibre layer changes, using Heidelberg Retinal Tomography (HRT), with alterations in retinal vascular oxygen saturation in NTG and POAG patients?
Are blood flow measurements, using colour Doppler imaging (CDI), correlated with alteration in retinal vascular oxygen in NTG and POAG patients?

Condition or Disease	Intervention/Treatment	Phase
Open Angle Glaucoma Low Tension Glaucoma

Detailed Description

Oximetry pictures will be taken and analysed.
CDI exam will be performed.
Visual field examen will be performed.
HRT will be performed.

Study Design

Study Type:

Observational

Actual Enrollment :

59 participants

Time Perspective:

Prospective

Official Title:

Validation of Retinal Oximetry in Glaucoma Patients: a Structural and Functional Correlation

Study Start Date :

Jan 1, 2011

Actual Primary Completion Date :

Dec 1, 2011

Actual Study Completion Date :

Dec 1, 2011

Arms and Interventions

Arm	Intervention/Treatment
healthy age machted controls
normal tension glaucoma patients
primary open angle glaucoma patients

Outcome Measures

Primary Outcome Measures

Comparison of oxygen saturation between glaucoma patients and healthy controls. [patients will be followed during their hospital stay, an average. of 3 hours]
Retinal oximetry gives us oxygen saturation values who will be compared between glaucoma patients and healthy controls and will be correlated to visual field mean defect, structure parameters from the HRT and velocity measurements with the CDI.

Eligibility Criteria

Criteria

Ages Eligible for Study:

18 Years and Older

Sexes Eligible for Study:

All

Accepts Healthy Volunteers:

Yes

Inclusion Criteria:

individuals over 18 years old
willing to sign an informed consent and able to comply with the requirements of the study
having no other ocular diseases besides glaucoma