Measurement of Retinal Auto Fluorescence With a Fluorescence Lifetime Imaging Ophthalmoscope

Study Overview
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Brief Summary
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Fluorescent lifetime microscopy has emerged as a useful tool to study fluorescent lifetimes in vitro. Fluorescence lifetime represents the average amount of time a fluorophore remains in the excited state following excitation and depends on the fluorophores molecular environment. Fluorescence lifetime ophthalmoscopy (FLIO) is a technique which can quantify fluorescence lifetimes in the human retina in vivo. The purpose of this study is to investigate fluorescence lifetime characteristics in the human retina by using a FLIO. The investigators hypothesize that FLIO will allow to identify areas of retinal metabolic stress such as ischemia by detecting changes in fluorescence lifetimes.

Detailed Description
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Background Ophthalmic imaging has made considerable progress in the last years. Especially the introduction of optical coherence tomography and the scanning laser ophthalmoscope has helped to understand the structural changes underlying various retinal diseases. However, the appearance of structural changes during retinal disease often represents irreversible functional loss with only limited treatment options. In order to prevent loss of vision, retinal diseases should ideally be diagnosed before structural changes occur. This can be achieved by imaging metabolic changes of the retina as most retinal diseases such as age related macular degeneration or diabetic retinopathy are associated with distinct metabolic changes, mainly related to oxidative stress. Recently, a novel device for imaging fluorescent lifetimes of the retina in vivo, the fluorescent lifetime ophthalmoscope (FLIO), has been developed. This device is able to measure fluorescence lifetimes in the retina on a macroscopic level and may be able to shed new light on metabolic diseases of the retina. Objective To define fluorescence lifetime characteristics in healthy patients and patients with various retinal diseases. Methods The investigators will use a novel device, the fluorescence lifetime ophthalmoscope (FLIO) to investigate fluorescence lifetimes in the human retina.

Official Title
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Measurement of Retinal Auto Fluorescence With a Fluorescence Lifetime Imaging Ophthalmoscope

Conditions
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Autofluorescence Imaging, Neuroimaging

Intervention / Treatment
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* Device: Fluorescence lifetime ophthalmoscope


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Subject must be willing to give written informed consent Healthy volunteers 18 years of age or greater Patients 18 years of age or greater No significant media opacities Exclusion Criteria Opacities of ocular media excluding detailed observation of the retina

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 |
| --- | --- |
| Healthy patients<br>Healthy patients | Device: Fluorescence lifetime ophthalmoscope<br>* All patients and healthy subjects will be imaged with the fluorescence lifetime ophthalmoscope<br>|
| Patients with various retinal diseases<br>Various retinal diseases (vascular, hereditary, degenerative) | Device: Fluorescence lifetime ophthalmoscope<br>* All patients and healthy subjects will be imaged with the fluorescence lifetime ophthalmoscope<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Fluorescence lifetime measured by a fluorescence lifetime imaging ophthalmoscope | Measured by fluorescence lifetime variable (TAU). Measured once; in some patients, up to 4 measurements within 2 years will be done | at baseline | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Repeatability of FLIO | Two independent measurements | at baseline |