“Retinal ischaemia in diabetic retinopathy
Research type
Research Study
Full title
“Retinal ischaemia in diabetic retinopathy: The role of endothelial progenitor cells modulating its development and progression”
IRAS ID
137820
Contact name
Noemi Lois
Contact email
Sponsor organisation
Belfast Health & Social Care Trust
Research summary
Summary of Results
This study monitored a group of 52 patients with diabetic retinopathy (damage to the blood vessels of the retina caused by diabetes) over two years. In particular, we evaluated changes in the closure of fine blood vessels in the retina, known as capillary nonperfusion, which often occurs in diabetes due to high blood sugar levels. The initial analysis involved investigating the effect of capillary nonperfusion on retinal function (i.e., how sensitive the retina is at detecting light). Other factors which we will explore that may be involved in the development and progression of capillary nonperfusion, include oxygen levels in retinal vessels, endothelial progenitor cells (special cells responsible for regenerating the lining of blood vessels), stem cells (cells which can be divided to become specialised cells with different functions), and inflammatory cells (which cause swelling).
The analysis of the association between capillary nonperfusion and retinal function included 44 eyes (2449 retinal points) of 44 adult patients (aged >18 years). These patients had type 1 or type 2 diabetes and diabetic retinopathy with at least one eye that hadn’t been treated, and no other retinal disorders. Twenty-seven eyes (1439 retinal points) were included in the follow-up analysis at one year and 12 eyes (545 retinal points) at two years. Fundus fluorescein angiography (a test that involves injecting a fluorescent dye to clearly show the retinal vessels) and visual field tests (to measure retinal function at 57 different retinal points) were carried out in all of these patients. The results of both were then mapped to each other to work out the relationship between retinal structure and function.
There was strong evidence to suggest that retinal function was reduced in areas of capillary nonperfusion compared to healthy retina. Retinal function was not found to be related to the length of time patients had diabetes, however, the amount of capillary nonperfusion became greater with a longer duration of diabetes. Reduced retinal function was found in eyes with higher amounts of capillary nonperfusion, but when correcting for other factors, such as age, gender, severity of diabetic retinopathy at the start of the study, and blood sugar levels, which may influence retinal function, the association was less strong (but did approach statistical significance).
Retinal function changed only gradually during the study period. This suggests that if in the future treatments become available for capillary nonperfusion, there would be time to treat before retinal function is lost. The findings of the study are also important in the design of future clinical trials; as functional deterioration seems to occur gradually, the potential beneficial effects of any new therapies may require longer trial periods to become apparent.
Data collection for this project was completed in December 2023 and these findings are currently being prepared for publication. There is much further work pending analysis and writing up on the other factors of interest to complete.REC name
HSC REC A
REC reference
14/NI/0076
Date of REC Opinion
17 Jun 2014
REC opinion
Further Information Favourable Opinion