A nationwide clinical trial for patients with the eye condition vitreous haemorrhage due to proliferative diabetic retinopathy investigating whether early eye surgery and laser treatment is a safe and better option for improving visual outcomes than the current standard of care

Plain English summary of protocol

Background and study aims
The most common cause of severe vision loss in people with diabetes is proliferative diabetic retinopathy (PDR). This condition affects about 3% of the UK population with diabetes, most being of working age. In PDR, the eye grows new blood vessels on the retina. The retina needs to be treated urgently by laser so that these blood vessels disappear or become inactive. If left untreated, these blood vessels can bleed into the vitreous region of the eye (termed vitreous haemorrhage [VH]) causing a sudden drop in vision and a delay to laser treatment. Nearly 50% of patients who develop PDR may still experience VH within 5 years despite good laser treatment. VH due to PDR is a global health problem that needs a new treatment strategy. The current Standard-of-Care (SoC) for patients involves:
1. A period of waiting for the bleeding to clear naturally, which usually lasts months.
2. Once the bleeding resolves, repeated laser treatments to prevent rebleeding.
3. If the blood does not clear sufficiently to apply laser treatment (about 20% of cases), the vitreous gel with blood is removed surgically (called vitrectomy) with laser treatment applied at the time of surgery. This procedure is typically offered after a long period of observation and several hospital appointments.
Clinical trials in the 1980s showed that patients with dense VH who underwent vitrectomy within 6 months had greater vision improvement, however, this approach was not recommended due to the risks of surgery. Since then, techniques and equipment for performing vitrectomy have advanced significantly reducing the risks of surgery.
This study aims to investigate whether for patients with VH due to PDR, early vitrectomy with laser treatment applied at the time of surgery is a safe and better option for improving visual outcomes, allowing faster visual rehabilitation, and reducing hospital appointments than the current SoC.

Who can participate?
Adults (aged 18 years and above) who have diabetes type 1 or 2 and vision impairment due to a diagnosis of VH due to PDR.

What does the study involve?
The study involves patients being randomly assigned to one of two treatment groups. One group will undergo SoC as described in the background. The other group will have surgery + laser treatment within 4 weeks of joining and a safety visit 2 weeks after their surgery + laser appointment. They will then follow a SoC pathway so if they require additional laser treatments or other interventions this will be provided. All patients on the trial will be followed up every 4 months over a 12-month period where they will undergo vision and optical function assessments, and take part in questionnaires to understand their quality of life and patient safety reviews. On entering and exiting the trial all patients will also undergo a blood test. Patients will be free to exit the trial at any point if they wish to do so.

What are the possible benefits and risks of participating?
This study will provide patients and the clinical community with information on the risk-to-benefit ratio of early vitrectomy for VH due to PDR. Participants assigned to the early surgery + laser treatment group and continuing for the full follow-up duration of 12 months would potentially benefit from faster visual recovery, improved visual outcomes, fewer complications, and reduced burden of outpatient visits and treatments compared to the current standard of care. However, the risks of participating are that, despite early surgery, patients may require postoperative intervention due to complications (e.g., detachment of the retina), infection, or limited response to the treatment. As with any surgery there will also be an intraoperative risk. Intra- and post-operative risks are now significantly reduced due to improved surgical techniques. For those in the standard-of-care arm, the benefits will be that, if the VH resolves spontaneously or early laser treatment is effective, then patients will not need to be exposed to the risks of surgery. As this is the current patient care pathway, the risks of being in this arm are the same as the current risks of care. The delay to surgery for those whose VH does not spontaneously resolve or does not respond well to early laser treatment may mean the surgery (>4 months) is less effective or results in further complications. This will be explored in this study.

Where is the study run from?
The study will be run across 25 NHS sites from across the UK and will be managed by Moorfields Eye Hospital NHS Foundation Trust in London (UK).

When is the study starting and how long is it expected to run for?
April 2025 to March 2028

Who is funding the study?
This study is being funded by the Medical Research Council (MRC) and National Institute of Health and Care Research (NIHR), with contributions from the CSO in Scotland, Health and Care Research Wales and the HSC R&D Division, Public Health Agency in Northern Ireland.

Who is the main contact?
Louisa Wickham, louisa.wickham1@nhs.net

Contact information

Study information

Eligibility

Locations

Countries of recruitment

• England
• United Kingdom

Study participating centre

Sponsor information

Moorfields Eye Hospital NHS Foundation Trust
Hospital/treatment centre

162 City Road
London
EC1V 2PD
England
United Kingdom

Phone	+44 (0)207 253 3411
Email	moorfields.resadmin@nhs.net
Website	http://www.moorfields.nhs.uk/
"ROR"	https://ror.org/03zaddr67

Funders

Funder type

Government

Results and Publications

Editorial Notes

27/02/2025: Study's existence confirmed by the NIHR.