Caffeine Consumption in Glaucoma Patients and Healthy Subjects

Study Overview
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Brief Summary
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Caffeine is the most widely consumed drinking nutrient in the world. Caffeine effects various organs and the vascular system. It decreases ocular blood flow due to vasoconstriction.

Detailed Description
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Ingestion of caffeine in glaucoma patients and healthy subjects may decrease peripapillary and macular blood flow in the back of the eye. The primary objective of this study is to assess the acute changes in peripapillary and macular blood flow before and after an intake of oral caffeine (200 milligram tablet) in glaucoma patients and healthy subjects by using optical coherence tomography angiography (OCTA) scans. This novel imaging tool creates three-dimensional angiograms to assesses signal changes caused by flowing blood cells in a non-invasive angiogram scan. Blood flow is shown as vessel density measured in percentage.

Official Title
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Acute Changes in Optic Nerve Head (ONH) and Macular Blood Flow After Caffeine Consumption in Glaucoma Patients and Healthy Subjects: A Quantitative Optic Coherence Tomography Angiography (OCTA) Study

Conditions
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Glaucoma, Primary Open Angle

Intervention / Treatment
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* Dietary Supplement: Caffeine tablet


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: age 18 to 90 years diagnosis of primary open angle glaucoma (Mild, Moderate and Advanced) healthy subjects with no eye disease Exclusion Criteria: Diseases, ophthalmic or systemic, that are likely to affect OCTA results greater than moderate cataract nystagmus inability to look at target macular degeneration other than mild drusen or pigmentary changes diabetic retinopathy neovascular glaucoma or non-glaucoma optic neuropathies current macular edema, prior laser to retina, inflammatory retinopathy or choroidopathy keratoconus, corneal ectasia, central corneal scarring rheumatologic diseases or Raynaud's phenomena pregnant and lactating women mental illness or alcohol addiction pre-existing bladder symptoms, cardiac disease or sleep disorder refractive spherical diopter greater than 5 or cylinder greater than 3 possible tolerance to caffeine (drinking more than 1 cup coffee per day).

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 90 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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Design Details

Primary Purpose: Diagnostic
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: All eyes will undergo imaging to measure blood flow in the back of the eye (retina and optic nerve) using the Avanti AngioVue HD OCTA (optical coherence tomography angiography)
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Glaucoma Patients<br>Eligible participants include patients with mild, moderate or advanced primary open angle glaucoma (POAG) or primary angle closure glaucoma (PACG). Each participant will complete baseline study tasks. Each participant will then receive one 200 mg caffeine tablet to ingest. Study tasks will be performed 1 hour and 2 hours after caffeine ingestion. | Dietary Supplement: Caffeine tablet<br>* Each eligible participant will receive one 200 mg caffeine tablet to ingest after completing all baseline study tasks.<br>|
| Active Comparator: Healthy controls<br>Eligible participants include healthy subjects with no eye diseases. Each participant will complete baseline study tasks. Each participant will then receive one 200 mg caffeine tablet to ingest. Study tasks will be performed 1 hour and 2 hours after caffeine ingestion. | Dietary Supplement: Caffeine tablet<br>* Each eligible participant will receive one 200 mg caffeine tablet to ingest after completing all baseline study tasks.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Blood flow change in back of eye before and after caffeine | Optical Coherence Tomography Angiography (OCTA) will be obtained using the Avanti AngioVue High Definition (HD) OCTA by Optovue. Images will include standard 4.5mm HD disc scan, 6mm HD retina scan, regular optic nerve head (ONH) structural scan, 3D-disc baseline scan and a regular ganglion cell complex analysis (GCCA) structural scan. This will measure blood flow changes in the back of the eye by imaging vessel density in percentage before then 1 and 2 hours after caffeine. | Baseline, Hour 1, Hour 2 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Primary Open Angle Glaucoma (POAG), Optical Coherence Tomography Angiography (OCTA), Caffeine, Macular Blood Flow, Peripapillary Blood Flow