The goal of this clinical trial is to evaluate whether remote ischemic conditioning (RIC) is a safe and effective treatment for non-proliferative diabetic retinopathy (NPDR) in adults aged 40-80 years with type 2 diabetes. The study aims to address the limitations of current treatments for NPDR by using RIC, a technique involving repeated cycles of ischemia and hypoxia stimulation to activate protective mechanisms against retinal damage.
The main questions it aims to answer are:
Does RIC improve the Diabetic Retinopathy Severity Score (DRSS) after one year of treatment? Does RIC reduce the incidence of vision-threatening proliferative diabetic retinopathy (PDR)? What are the changes in retinal neurovascular unit parameters, visual acuity, and retinal oxygen saturation after RIC treatment?
Participants will:
Undergo RIC therapy using a specialized device on both upper limbs (or a placebo intervention for the control group) for 1 year.
Complete 5 cycles of RIC or placebo treatment twice daily, 5 days per week. Receive routine care for diabetic retinopathy as per clinical guidelines.
Key outcome measures:
Primary outcome: Change in DRSS from baseline after one year. Secondary outcomes: Incidence of PDR, changes in visual acuity, retinal neurovascular unit measures, retinal oxygen saturation, and serum biomarkers (e.g., VEGF, CRP, IL-6).
This randomized, double-blind, placebo-controlled trial aims to recruit 68 participants to ensure 60 complete the study, accounting for a 13% dropout rate. The findings are expected to provide insights into RIC as a novel intervention for NPDR, reducing blindness risk and supporting future large-scale trials.
Age between 40 and 80 years.
Diagnosed with Type 2 diabetes mellitus.
Diagnosed with mild to moderate non-proliferative diabetic retinopathy (NPDR) with a DR Severity Score (DRSS) grade of 20-47D.
Capable of performing daily activities independently.
Presence of diabetic macular edema (macular thickness > 250 μm).
Significant eye diseases affecting evaluation, such as high myopia, severe cataract, corneal leucoma, glaucoma, retinal detachment, retinal vein occlusion, congenital eye diseases, ocular tumors, or severe infection.
History of ocular laser or intraocular surgery.
Poor imaging quality due to refractive media opacity.
Parallel
Remote Ischemic Conditioning Device
DeviceParticipants in this group will use a remote ischemic conditioning device that applies five cycles of 5-minute inflation at 200 mmHg followed by 5-minute deflation on both arms, twice daily, for at least five days per week over one year. The device is designed to enhance retinal oxygenation and reduce hypoxia-related damage.
Sham Remote Ischemic Conditioning Device
DeviceParticipants in this group will use the same remote ischemic conditioning device set to an inflation pressure of 60 mmHg to simulate the treatment. This placebo intervention follows the same timing and cycle frequency as the active intervention group.
Change in Diabetic Retinopathy Severity Score (DRSS)
The primary outcome measure is the change in the Diabetic Retinopathy Severity Score (DRSS) from baseline to 1 year after intervention. The DRSS is a standardized grading system used to assess the severity of diabetic retinopathy, with changes reflecting disease progression or improvement.
Incidence of Proliferative Diabetic Retinopathy (PDR)
The incidence of participants who progress to proliferative diabetic retinopathy (PDR) within one year after the intervention. PDR progression is identified based on clinical examination and fundus photography.
Change in Retinal Neurovascular Unit Parameters
Changes in parameters of the retinal neurovascular unit, including macular capillary densities (superficial and deep), radial peripapillary capillary density, ganglion cell complex thickness, and retinal nerve fiber layer thickness, assessed through optical coherence tomography angiography (OCTA) from baseline to 1 year.
Change in Retinal Oxygen Saturation
The change in retinal oxygen saturation levels measured using retinal oximetry between baseline and 1 year after intervention. Improvements are expected to reflect reduced retinal hypoxia.
Change in Visual Acuity
The change in best-corrected visual acuity (BCVA) measured using the Early Treatment Diabetic Retinopathy Study (ETDRS) chart between baseline and 1 year after intervention.
Incidence of Local Complications Related to Intervention
The incidence of experiencing local complications, including upper limb pain, erythema, edema, skin injury, and ischemia, related to the remote ischemic conditioning device during the one-year intervention period.
Retention Rate of Participants
The retention rate of participants who complete the one-year intervention without withdrawal. This measures feasibility and adherence to the intervention protocol.
Click on the lead sponsor to view all of their trials.
Xuxiang Zhang, MD
Lead sponsor
Xuanwu Hospital, Beijing
Sponsor institution
Xuanwu Hospital, Beijing
Collaborator
