Direct Discrimination of Quantum States by the Human Eye

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

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.

Study Overview

• Status: Recruiting
• Conditions: Age-Related Macular Degeneration
• Intervention / Treatment: Device: Structured Light Imaging Microscopy

Detailed Description

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.

• Study Type: Interventional
• Enrollment (Estimated): 50
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Benjamin Thompson, PhD; Phone Number: +852-3169-9631; Email: ben.thompson@cevr.hk
• Study Contact Backup: Name: Mukhit Kulmaganbetov, MD, PhD; Phone Number: +852-3169-9631; Email: mukhit.k@cevr.hk

Study Locations

• Hong Kong
  • Guangdong
    • Hong Kong, Guangdong, Hong Kong, 00000
      • Recruiting
      • Centre for Eye and Vision Research Limited
      • Contact: Peter CK Pang, PhD; Phone Number: +852-2766-7927; Email: csm@cevr.hk
      • Sub-Investigator: Taranjit Singh, BSc

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

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

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Diagnostic
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: Participants with Age-Related Macular Degeneration; Conducting the psychophysical task on the perception of OAM-coupled polarized light

Device: Structured Light Imaging Microscopy; 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).

What is the study measuring?

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)

Collaborators and Investigators

• Sponsor: Centre for Eye and Vision Research
• Collaborators: The Hong Kong Polytechnic University; University of Waterloo
• Investigators: Principal Investigator: Benjamin Thompson, PhD, Centre for Eye and Vision Research; Study Director: Mukhit Kulmaganbetov, MD, PhD, Centre for Eye and Vision Research

Study record dates

Study Major Dates

• Study Start (Actual): June 26, 2023
• Primary Completion (Estimated): July 1, 2024
• Study Completion (Estimated): October 1, 2024

Study Registration Dates

• First Submitted: May 31, 2023
• First Submitted That Met QC Criteria: June 9, 2023
• First Posted (Actual): June 22, 2023

Study Record Updates

• Last Update Posted (Actual): June 27, 2023
• Last Update Submitted That Met QC Criteria: June 26, 2023
• Last Verified: June 1, 2023

More Information

Terms related to this study

• Keywords: Age-Related Macular Degeneration; Retinal Imaging; Structured Light; Orbital Angular Momentum; Polarization Perception
• Additional Relevant MeSH Terms: Eye Diseases; Retinal Degeneration; Retinal Diseases; Macular Degeneration
• Other Study ID Numbers: SLIM

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: Anonymized data will be shared on request
• IPD Sharing Time Frame: After the publication of study results for an indefinite period.
• IPD Sharing Access Criteria: Upon reasonable request and approved by the study principal investigator.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No