Quantitative autofluorescence in fundus diseases
Research type
Research Study
Full title
Quantitative Autofluorescence (qAF) in Posterior uveitis
IRAS ID
211588
Contact name
Tomas Burke
Contact email
Sponsor organisation
University Hospitals NHS Foundation Trust
Duration of Study in the UK
0 years, 6 months, 31 days
Research summary
Summary of Research
Fundus Autofluorescence (FAF) is an imaging technique widely used in Ophthlalmology for assessing the relative levels of a material called 'lipofuscin' which builds up in the retina with age. In certain disease, the level of lipofuscin builds up more quickly and to much higher levels. As diseases progress and cells die, these levels of lipofuscin begin to fall.
When blue light of a certain wavelenght (488nm) is shone on the lipofuscin it exhibits the characteristic of 'autofluorescence', which means that it emits a light of a different wavelength. FAF images, which can be acquired on a type of camera called a Heidelberg Retinal Angiograph (HRA), are therefore a picture of the retina which demonstrates the relative distribution of lipofuscin by showing levels of high lipofuscin as bright, and low liplofuscin as dark. By modifying the HRA with a reference strip of known autofluorescence, it has become possible to quantify the brightness of the acquired image and so to determine the quantitative levels of autofluoresence, i.e. quantitative autofluorescence. As the brightness of the autofluorescent image is proportional to the amount of lipofuscin present, the qAF images allows us to indirectly measure levels of lipofusin in the living eye. Previously, levels of lipofuscin could only be measured after an eye was removed.
qAF provides us with a novel way to monitor patients' disease progression, as well as to assess the effect of potential treatments. Data validating this technique in normal patients and retinal degenerative conditions has recently been published. In this study we plan to utilize this technology in inflammatory ocular conditions to indirectly measure levels of lipofuscin.Summary of Results
The study was closed due to a combination of limited recruitment in the context of the COVID-19 pandemic, and the fact that the chief investigator left the NHS to work in a different country. The chief investigator was the only person in the department with the relevant skills to carry out the investigation in the study. The study had to be abandoned as a result. 24 of the target 70 study subjects were recruited. The data collection was therefore insufficient for analysis and will not be analysed. Hence, this final report is being made.
REC name
West of Scotland REC 5
REC reference
16/WS/0255
Date of REC Opinion
8 Dec 2016
REC opinion
Favourable Opinion