Investigating the Retardation Effect of OCTA-Guided Targeted Photocoagulation on the Progression of Non-Perfusion Areas in Diabetic Retinopathy Patients

Overview

This study aims to evaluate the impact of widefield OCTA-guided selective photocoagulation on the progression of diabetic retinopathy (DR) by comparing the control of non-perfusion (NP) areas, DR grading, and management of other DR lesions. The study is designed as a parallel randomized controlled trial. From February 2025 to August 2026, 30 diabetic patients attending the Ophthalmology Department of Sichuan Provincial People's Hospital will be enrolled. Using a simple randomization method, one eye of each patient will be assigned to the intervention group, while the contralateral eye will serve as the control, resulting in 30 eyes in each group. The intervention group will undergo OCTA-guided selective photocoagulation, specifically using a grid pattern (3x3) of spot laser applied once to the NP area, extending one spot diameter beyond the NP boundary. Each session will last 10-20 minutes. The control group will receive no treatment. The study will compare changes in NP area, DR grading progression, and control of other DR lesions at 3, 6, 9, and 12 months between the two groups.

Interventions

• Procedure Targeted laser photocoagulation guided by OCTA (Optical Coherence Tomography Angiography)
  The patient's eyes were first scanned using the Topcon OCTA (five-field montage) with a 24×20mm and a 6×6mm scan range. After enrollment, the patient underwent treatment on the same day in the retinal laser room. The laser treatment was performed by the same ophthalmologist. After obtaining baseline fundus images, the treating ophthalmologist overlaid the OCTA images onto the fundus images using retinal vessel alignment to guide targeted photocoagulation of the retinal non-perfusion (NP) areas u

Primary outcome measures

• The area size of NP (in PD units) in two groups of eyes at 0, 3, 6, 9, and 12 months [Time frame: From enrollment to reexamination at 0,3,6,9, and 12 months]

Secondary outcome measures (4)

• The number of microaneurysms, intraretinal microvascular abnormalities (IRMA) in both groups of eyes at 0, 3, 6, 9, and 12 months [Time frame: From enrollment to reexamination at 0,3,6,9, and 12 months]
• The number of neovascularization (NV) in both groups of eyes at 0, 3, 6, 9, and 12 months [Time frame: From enrollment to reexamination at 0,3,6,9, and 12 months]
• Area of foveal avascular zone (FAZ) at 0, 3, 6, 9, and 12 months in two groups of eyes [Time frame: From enrollment to reexamination at 0,3,6,9, and 12 months]
• DR grading at 0, 3, 6, 9, and 12 months in two groups of eyes [Time frame: From enrollment to reexamination at 0,3,6,9, and 12 months]

Eligibility criteria

Inclusion criteria

• Age ≥ 18 years
• Type 1 or Type 2 diabetes mellitus
• Clinical dilated fundus examination and Optos imaging within 7 fields showing diabetic retinopathy (DR) lesions no more severe than severe non-proliferative diabetic retinopathy (NPDR)
• Optical coherence tomography angiography (OCTA) demonstrating non-perfusion (NP) areas greater than 1 disc diameter (PD) in both eyes
• Diabetic retinopathy in both eyes at the same stage, with the total NP area within the observed range of OCTA being comparable (difference less than 5 PD)
• Absence of other ocular diseases that could lead to the formation of retinal microaneurysms
• Absence of other ocular diseases that could lead to the formation of retinal non-perfusion areas
• No diabetic macular edema involving the fovea
• No history of retinal laser treatment
• No history of intravitreal injection therapy within the past 3 months
• No history of ocular surgery other than cataract surgery
• Ability to cooperate with all examinations and provide informed consent

Exclusion criteria

• Optical media opacity affecting OCTA imaging
• Patients with difficulties in cooperating with laser treatment
• Patients with renal failure, diabetic neuropathy, or severe cardiovascular diseases
• Patients who are unlikely to complete follow-ups every 3 months, as well as those residing in other provinces
• Patients requiring early PRP (conditions include: combined DME, planned cataract surgery, pregnancy planning, early PDR, poor follow-up compliance, severe vision loss in the other eye, poor glycemic control, poor renal function, or type 1 diabetes)
• FFA showing NP greater than 10 PD within the ETDRS area or a total NP area greater than 75 PD, or an ischemia index greater than 35%

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

Randomized

Model

Parallel assignment

Masking

Single blind

Primary purpose

Treatment

Study locations

China · 1 center

• Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital — Chengdu

Identifiers

NCT: NCT06821633 · 2024-KY740-1

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗