Performance of Long-wavelength Autofluorescence Imaging

Not Applicable

Completed

• Conditions: Retinal Disease; Retinal Dystrophies; Retinal Degeneration
• Interventions: Device: Long-wavelength autofluorescence imaging

• Registration Number: NCT03592017
• Lead Sponsor: Oxford University Hospitals NHS Trust

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.

Study Timeline

• Study First Submitted: 2018-07-09
• Study First Submitted QC: 2018-07-09
• Study First Posted: 2018-07-19
• Study Start: 2018-10-01
• Primary Completion: 2024-04-09
• Study Completion: 2024-04-09
• Status Verified: 2024-08
• Last Update Submitted: 2024-08-19
• Last Update Posted: 2024-08-21

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 262

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

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Patients with various retinal diseases	Long-wavelength autofluorescence imaging	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
Healthy participants	Long-wavelength autofluorescence imaging	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.

Primary Outcome Measures

Name	Time	Method
Performance of long-wavelength autofluorescence imaging	1 day	The sensitivity and specificity to detect characteristics in retinal diseases will be investigated in patients with various retinal diseases and compared to conventional imaging methods

Secondary Outcome Measures

Name	Time	Method
Optimization of the signal of long-wavelength autofluorescence imaging using different laser and filter settings	1 day	To optimize the signal of long-wavelength autofluorescence imaging, the fluorescence intensity of the different laser sources and filter settings will be assessed.
Quantification of the optimized signal of long-wavelength autofluorescence imaging in healthy controls and participants with various retinal diseases	1 day	To quantify the optimized signal of long-wavelength autofluorescence imaging the absolute fluorescence intensity compared to a fluorescent reference will be assessed in patients with various retinal diseases and compared to healthy controls

Trial Locations

Locations (1)

Oxford Eye Hospital; 🇬🇧 Oxford, United Kingdom