Performance of Long-wavelength Autofluorescence Imaging

NCT ID: NCT03592017

Last Updated: 2024-08-21

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 262 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2018-10-01
• Study Completion Date: 2024-04-09

Brief Summary

Fundus autofluorescence imaging has become an important diagnostic tool in ophthalmology, guiding diagnosis and assessment of progression of retinal diseases. This study investigates the performance of optimized long-wavelength autofluorescence imaging. To achieve this goal, the investigators will determine an optimal long wavelength excitation light and investigate the autofluorescence signal intensity in normals and patients with different retinal diseases. The diagnostic performance of the long-wavelength autofluorescence will be evaluated by assessing sensitivity and specificity for diagnosing a variety of degenerative retinal diseases and by comparing it to conventional autofluorescence.

Detailed Description

Fundus autofluorescence (AF) imaging of the retina with confocal scanning laser ophthalmoscopy has been established as a non-invasive imaging modality for the diagnosis of retinal and macular diseases. Long-wavelength near-infrared autofluorescence (excitation: 787 nm, LW-AF) is a new, innovative alternative to the classic autofluorescence imaging using 488 nm blue excitation light. Excitation of the fluorophores at the ocular fundus using a longer wavelength has several advantages. However, with the current imaging technique the autofluorescence signal and thus image quality is considerably lower compared to conventional short-wavelength autofluorescence (SW-AF). This may be the main reason for the currently limited application and scarce scientific publications on this technique.

Therefore, the objective of this study is to assess the performance of an optimized setup of long-wavelength autofluorescence imaging in clinical routine applications. For this purpose, additional laser sources will be integrated into a scanning laser ophthalmoscope and the performance with regards to image quality will be investigated systematically using different excitation wavelengths and filter combinations in healthy controls.

In a next step, the signal intensity will be quantified using an integrated fluorescent reference. First, factors affecting measurements will be identified, followed by generation of a normative database. Subjects with various retinal diseases will then be investigated and compared to the normative database.

Finally, the diagnostic performance of long-wavelength autofluorescence imaging to detect retinal degenerative diseases will be investigated and compared to conventional imaging techniques.

Conditions

Retinal Disease; Retinal Degeneration; Retinal Dystrophies

Study Design

• Allocation Method: NON_RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: DIAGNOSTIC
• Blinding Strategy: NONE

Study Groups

Patients with various retinal diseases

Patients with various retinal diseases will be examined using long-wavelength autofluorescence imaging to assess the performance compared to conventional imaging methods and to quantify the signal compared to a normative database

Group Type: EXPERIMENTAL

Long-wavelength autofluorescence imaging

Intervention Type: DEVICE

Long-wavelength autofluorescence imaging will be performed with a prototype confocal scanning laser (cSLO) ophthalmoscope which will be equipped with additional laser sources and a reference for quantification of the signal. The experimental long-wavelength laser sources will be integrated into a custom-modified Spectralis HRA cSLO from Heidelberg Engineering. The additional laser sources will operate with long wavelength which are less energetic compared to the conventional short-wavelength lasers used currently for routine autofluorescence imaging. All safety standards have been considered and the light exposure for all imaging modes is well below the exposure limits for Class 1 and Class1M laser products as defined in the standard IEC 60825-1, edition 3.0, 2014-5.

Healthy participants

Healthy participants will be examined using long-wavelength autofluorescence imaging to optimize the signal with additional laser sources and device settings and to compile a normative database for the quantification of the signal.

Group Type: EXPERIMENTAL

Long-wavelength autofluorescence imaging

Intervention Type: DEVICE

Long-wavelength autofluorescence imaging will be performed with a prototype confocal scanning laser (cSLO) ophthalmoscope which will be equipped with additional laser sources and a reference for quantification of the signal. The experimental long-wavelength laser sources will be integrated into a custom-modified Spectralis HRA cSLO from Heidelberg Engineering. The additional laser sources will operate with long wavelength which are less energetic compared to the conventional short-wavelength lasers used currently for routine autofluorescence imaging. All safety standards have been considered and the light exposure for all imaging modes is well below the exposure limits for Class 1 and Class1M laser products as defined in the standard IEC 60825-1, edition 3.0, 2014-5.

Interventions

Long-wavelength autofluorescence imaging

Long-wavelength autofluorescence imaging will be performed with a prototype confocal scanning laser (cSLO) ophthalmoscope which will be equipped with additional laser sources and a reference for quantification of the signal. The experimental long-wavelength laser sources will be integrated into a custom-modified Spectralis HRA cSLO from Heidelberg Engineering. The additional laser sources will operate with long wavelength which are less energetic compared to the conventional short-wavelength lasers used currently for routine autofluorescence imaging. All safety standards have been considered and the light exposure for all imaging modes is well below the exposure limits for Class 1 and Class1M laser products as defined in the standard IEC 60825-1, edition 3.0, 2014-5.

Intervention Type: DEVICE

Eligibility Criteria

Inclusion Criteria

• Age 18 years or above
• Defined retinal disease (patients) or no known retinal disease (healthy participants)
• Participants willing to read and understand the study information and provide informed consent
• Participants agree to have some examinations and photographs taken from their eyes

Exclusion Criteria

• Significant opacities of the ocular media
• difficulties positioning still in front of the camera
• any ocular/ general disease known to affect recordings and/or analysis of retinal images
• Pupil diameter <5mm

• Minimum Eligible Age: 18 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

Oxford University Hospitals NHS Trust

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Peter Charbel Issa, DPhil, MD

Role: PRINCIPAL_INVESTIGATOR

Oxford Eye Hospital, The West Wing John Radcliffe Hospital Oxford, OX3 9DU

Locations

Oxford Eye Hospital

Oxford, , United Kingdom

Countries

United Kingdom

Other Identifiers

13703

Identifier Type: -

Identifier Source: org_study_id