DIAMONDS
Research type
Research Study
Full title
Diabetic Macular Oedema and Diode Subthreshold Micropulse Laser (DIAMONDS): A pragmatic, multicentre, allocation concealed, prospective, randomised, non-inferiority double-masked trial
IRAS ID
207927
Contact name
Noemi Lois
Contact email
Sponsor organisation
Belfast HSC Trust
Duration of Study in the UK
4 years, 1 months, 31 days
Research summary
Research Summary
DIAMONDS is a Randomised Clinical Trial that is being carried out in UK to determine the clinical effectiveness and cost-effectiveness of micropulse laser, compared with standard laser, for the treatment of diabetic macular oedema.
Diabetic retinopathy is the damage of the retina caused by diabetes. People with diabetes and diabetic retinopathy may lose vision as a result of them developing what is called diabetic macular oedema (DMO). DMO is the most common complication of diabetes in the back of the eye. In DMO fluid leaks in the centre of the retina; the accumulation of the fluid reduces the vision, as the retina (the layer in the back of the eye responsible for our sight) needs to be dry to work properly. If the fluid is left untreated, permanent and irreversible visual loss will occur.
The amount of fluid in the macula can be measured by doing a scan of the eye called optical coherence tomography (OCT). Depending on the amount of fluid present in the macula, people with DMO will be offered medicines known as anti-vascular endothelial growth factor (anti-VEGF) or laser treatment.
The National Institute of Health and Care Excellence (NICE) found that laser treatment was effective in people with diabetic macular oedema and retinas that had been thickened by fluid but below to a certain limit (when the centre of the retina is less than 400 microns in thickness as measured by the OCT) and offers good value for money; better than anti-VEGF injections. Both, standard laser and micropulse laser, are being used currently in ophthalmic clinics across the world.
Summary of Results
The retina is a layer at the back of the eye. Its centre is called “macula” and is responsible for central vision. Some people with diabetes develop diabetic macular oedema (DMO). In DMO fluid leaks from retinal blood vessels and builds-up at the macula resulting in sight loss. DMO can be mild or severe; this can be determined measuring the thickness of the macula, which is measured in microns. One micron is one-thousandth of a millimetre. In mild DMO, the thickness of the macula increases, but is less than 400 microns.
Patients with mild DMO can be treated with laser. There are two laser types:
Standard threshold laser has been available for many years. It works clearing the DMO but produces a “burn” (“scar”) in the retina. Subthreshold micropulse laser is newer. It doesn’t produce a burn but clears the DMO too. The lack of a burn, however, led to doubts about whether this laser works as well as standard laser because "no burn” was taken to mean “less benefit”.These doubts led to the DIAMONDS trial, which compared these two lasers for people with mild DMO. Two-hundred and sixty-six people suitable for either laser joined the study at 16 NHS hospitals across the UK; 133 received standard threshold laser and 133 received subthreshold micropulse laser. The choice of laser was determined by chance.
DIAMONDS found subthreshold micropulse laser was as good (“clinically equivalent”) as standard threshold laser for helping people’s vision, reducing macula thickness, allowing people to meet driving standards, and maintaining their quality of life, both in general terms and for vision in particular. There was a small increase (less than one session on average per person) in the number of laser treatment sessions needed with subthreshold micropulse laser. Costs of both laser treatments were about the same.
REC name
HSC REC A
REC reference
16/NI/0145
Date of REC Opinion
17 Aug 2016
REC opinion
Further Information Favourable Opinion