Reproducibility of Blood Flowmetry in Human Retina Using the Nidek Laser Speckle Flowgraphy LSFG-NAVI System

Study Overview
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Brief Summary
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In addition to intraocular pressure blood perfusion pressure in the optic nerve is an important factor determing the cause of glaucoma. Increasing evidence suggests that in glaucoma patients retinal blood may be decreased.

Detailed Description
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According to the World Health Organization (WHO) glaucoma is the second leading cause of blindness. Glaucoma is a global problem, which is becoming even more important as the human life expectancy increases. Although the causes of glaucoma are uncertain, mainly intraocular pression (IOP), genetics, and ocular blood perfusion pressure in the optic nerve determine the cause of the disease. Increasing evidence suggests that in glaucoma patients retinal blood flow is decreased leading to progression and to damage of the optic nerve. In order to measure the peripapillary blood flow a variety of devices using different techniques of flowmetry have been developed. In this study, the reproducibility of the retinal flowmetry measured with the LSFG-NAVI device from Nidek will be investigated. A high reproducibility is crucial for the clinical value of any measuring device.

Official Title
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Prospective, Non-randomised, Non-controlled Study of Reproducibility of Blood Flowmetry in Human Retina Using the Nidek Laser Speckle Flowgraphy LSFG-NAVI System

Conditions
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Open Angle Glaucoma, Normal Tension Glaucoma, Healthy

Intervention / Treatment
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* Diagnostic Test: LASER SPECKLE FLOWGRAPHY


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: signed Patient Informed Consent form Be at least 18 years old Diagnosis of primary or secondary open-angle glaucoma or normal tension glaucoma or healthy controls Exclusion Criteria: Age < 18 years Inability to follow the procedures of the study, e.g. due to language problems, psychological disorders, dementia, etc. of the participant. No vulnerable participants will be included in this study.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| open-angle glaucoma<br>patients with a diagnosis of open-angle glaucoma, i.e. untreated IOP >21mmHg plus glaucomatous disc changes and/or visual field defects typical for glaucoma | Diagnostic Test: LASER SPECKLE FLOWGRAPHY<br>* Non-invasive, real-time imaging and measurement of ocular blood flow of the optic disc and peripapillary region<br>|
| normal tension glaucoma<br>patients with a diagnosis of normal tension glaucoma, i.e. untreated IOP </=21mmHg plus glaucomatous disc changes and/or visual field defects typical for glaucoma | Diagnostic Test: LASER SPECKLE FLOWGRAPHY<br>* Non-invasive, real-time imaging and measurement of ocular blood flow of the optic disc and peripapillary region<br>|
| healthy controls<br>individuals with normal optic disc and IOP </21mmHg and normal visual fields | Diagnostic Test: LASER SPECKLE FLOWGRAPHY<br>* Non-invasive, real-time imaging and measurement of ocular blood flow of the optic disc and peripapillary region<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Coefficients of variation (COV) | COVs from 3 measurements of ocular blood flow at visit 1 of observer 1 and at visit 1 of observer 1 and from observer 2 will be computed. | 1 month | 
| intraclass correlation coefficients (ICCs) | Intraobserver ICC, interobserver ICC, and inter-session ICC will be computed | 1 month | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Cofounder | Blood pressure will be checked as potential cofounder | 1 month | 
| Cofounder | heart rate will be checked as potential cofounder | 1 month | 
| Cofounder | spherical equivalent will be checked as potential cofounder | 1 month | 
| Cofounder | intraocular pressure will be checked as potential cofounder | 1 month | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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glaucoma, retinal blood flow, ocular perfusion pressure