Direct Discrimination of Quantum States by the Human Eye

Study Overview
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Brief Summary
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Age-related macular degeneration (AMD), is a debilitating eye disease that causes a loss of central vision. The prevalence of AMD increases exponentially with age and causes a significant impact through both medical expenses and the social and economic costs associated with vision loss. AMD is the global leading cause of blindness among people over the age of 60. Detection of this eye disease at early stages coupled with prompt treatment can prevent vision loss; however, modern diagnosis methods are ineffective at diagnosis of AMD before vision loss occurs. While a range of available treatment options has been effective at slowing vision loss due to AMD, no treatment exists which can recover lost vision. The investigators propose to apply tools developed in quantum information science to diagnose AMD before vision has been affected, drastically improving health outcomes for patients with AMD.

Detailed Description
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There has been tremendous progress in generating and detecting structured light which possesses advantageous propagation characteristics such as quantized orbital angular momentum (OAM), non-diffraction, and self-healing. These special beams have found applications in microscopy, encoding and multiplexing of communications, and manipulation of matter. Here the investigators bring the structured light toolbox to vision sciences for the first time and expand the space of possible stimuli. A healthy macula possesses azimuthally ordered dichroic fibres that act as a radial polarization filter, enabling a typical person to perceive linearly polarized light through the entoptic phenomena known as Haidinger's brushes. Despite significant interest in the application of this phenomenon to the detection of age-related macular degeneration, no device has currently seen widespread adoption in a clinical environment. This is due to the difficulty in observing Haidinger's brush, the imprecise measurements that this test can extract, and the difficulty in instructing patients during these tests. Leveraging the quantum-inspired toolbox developed in the field of structured light, the investigators can project polarization-coupled OAM states of light directly on a person's retina. This enables the investigators to create arbitrary entoptic patterns in a person's vision based on the structure and chemical composition of their subjective macula, and the investigators have the opportunity to develop a litany of novel diagnostic tests to characterize and quantify the health of the macula.

Official Title
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Direct Discrimination of Quantum States by the Human Eye With Macular Degeneration

Conditions
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Age-Related Macular Degeneration

Intervention / Treatment
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* Device: Structured Light Imaging Microscopy


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Participants who are clinically diagnosed with a vision disease affecting their macula Older adults who are matched for age. Participants who are clinically diagnosed with glaucoma Participants who have normal vision. One aged-matched control with normal vision will be recruited for each of the diagnosed groups (born in the same year). Exclusion Criteria: Participants with any additional eye diagnosis or condition

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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Design Details

Primary Purpose: Diagnostic
Intervention Model: Single Group Assignment
Interventional Model Description: Within-subject, measuring the threshold SL-based entoptic phenomenon circular obstruction size of the radial retinal polarizer
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Participants with Age-Related Macular Degeneration<br>Conducting the psychophysical task on the perception of OAM-coupled polarized light | Device: Structured Light Imaging Microscopy<br>* Conducting the psychophysical task on the perception of OAM-coupled polarized light created using the experimental setup - Structured Light Imaging Microscopy (SLIM). Four types of vortex orbital angular momentum, differing by the number of fringes l=5;10; 15;20, will be presented for 0.5s per trial during which an azimuthally varying entoptic profile rotated clockwise or counterclockwise. A circular mask with a varying radius will be placed at fixation, thus the task will be performed at varying eccentricities. Circular obstruction of the area will be achieved due to the high refresh-rate structured light modulator. The threshold mask size will be changed by a 2up/1down staircase method (71% accuracy for the estimation of mask size).<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Perception of the structured light | Assessment of the participant's ability to see the entoptic phenomena created using the structured light (SL) - orbital angular momentum (OAM) coupled polarized light. Various SL vortex and radial patterns will be projected using the custom research-based laser optical setup | Approximately 10 minutes, Screening and Training day (Session 1) | 
| Radius of the radial retinal polarizer | Calculation of the radius of the central obstruction. From a total of 14 reversal trials, the six last values of the mask size will be used for the calculation of the threshold mask size mean (r mean). The standard deviation will be computed from the variance of these last six trials | Approximately 30 minutes, on the completion of the study (Session 6) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Thickness of retina and retinal layers | Measurement of the retinal layers' thickness and total neuroretina | Approximately 10 minutes, Screening and Training day (Session 1) | 
| Contrast sensitivity | Computer-based measurement of contrast sensitivity | Approximately 5 minutes, Screening and Training day (Session 1) | 
| Fundus photography | Imaging the retina using white light. The diameter of the optic nerve head will be measured in order to calculate the degree/pixel ratio for each participant | Approximately 5 minutes, Screening and Training day (Session 1) | 
| Ocular biometry measurement | Measurement of the central corneal thickness and axial eye length | Approximately 5 minutes, Screening and Training day (Session 1) | 
| Macular pigment optical density measurement | Computer-based measurement of the macular pigment optical density (MPOD) | Approximately 10 minutes, Screening and Training day (Sessions 1 and 2) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Age-Related Macular Degeneration, Structured Light, Orbital Angular Momentum, Polarization Perception, Retinal Imaging