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NCT Number: NCT05913063

Direct Discrimination of Quantum States by the Human Eye

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.

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Key information

Conditions

Age-Related Macular Degeneration Eye Diseases Macular Degeneration Retinal Degeneration Retinal Diseases

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Centre for Eye and Vision Research Limited

Hong Kong, Guangdong, 00000

Location status: Recruiting

Location contact

Peter CK Pang, PhD

CONTACT

[email protected]

+852-2766-7927

Taranjit Singh, BSc

SUB_INVESTIGATOR

About this study

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.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

Structured Light Imaging Microscopy

Device

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).

Primary outcomes

  1. Perception of the structured light

    Time frame: Approximately 10 minutes, Screening and Training day (Session 1)

    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

  2. Radius of the radial retinal polarizer

    Time frame: Approximately 30 minutes, on the completion of the study (Session 6)

    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

Secondary outcomes

  1. Thickness of retina and retinal layers

    Time frame: Approximately 10 minutes, Screening and Training day (Session 1)

    Measurement of the retinal layers' thickness and total neuroretina

  2. Contrast sensitivity

    Time frame: Approximately 5 minutes, Screening and Training day (Session 1)

    Computer-based measurement of contrast sensitivity

  3. Fundus photography

    Time frame: Approximately 5 minutes, Screening and Training day (Session 1)

    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

  4. Ocular biometry measurement

    Time frame: Approximately 5 minutes, Screening and Training day (Session 1)

    Measurement of the central corneal thickness and axial eye length

  5. Macular pigment optical density measurement

    Time frame: Approximately 10 minutes, Screening and Training day (Sessions 1 and 2)

    Computer-based measurement of the macular pigment optical density (MPOD)

Study contacts

Contact information is provided by the study sponsor or research team.

Benjamin Thompson, PhD

CONTACT

[email protected]

+852-3169-9631

Mukhit Kulmaganbetov, MD, PhD

CONTACT

[email protected]

+852-3169-9631

Sponsors and collaborators

Lead sponsor

Centre for Eye and Vision Research

Other

Collaborators

  • The Hong Kong Polytechnic University
  • University of Waterloo

Registry information

Official study title

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

Important dates

Study start
2023
Primary completion
2029
Study completion
2029
First posted
Jun 22, 2023
Registry last updated
Mar 18, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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