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NCT Number: NCT05728476

Microinvasive Pars Plana Vitrectomy Combined ILM Peeling Versus Anti-VEGF Intravitreal Injection for Treatment-naïve Diabetic Macular Edema

Diabetic macular edema (DME) is the main cause of vision loss in patients with diabetes. At present, anti-vascular endothelial growth factor (VEGF) intravitreal injection is the first-line therapy for DME, nevertheless, some patients do not respond well to anti-VEGF agents and often require multiple injections, which increases the psychological and economic burden of patients. Microinvasive pars plana vitrectomy (PPV) has been proven to be safe and effective for refractory DME. However, there are few studies on treatment-naïve DME. The purpose of this study is to explore whether early PPV combined with internal limiting membrane (ILM) peeling can reduce the treatment burden of DME patients, prevent vision loss, and maintain long-term stabilization of diabetic retinopathy.

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Key information

Conditions

Diabetic Macular Edema Conbercept Pars Plana Vitrectomy

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Tianjin medical university eye hosipital

Tianjin, Tianjin Municipality, China

Location status: Recruiting

Location contact

Bojie Hu

CONTACT

[email protected]

13612130943

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • ≥18 years of age
  • Patients and their families fully understand the research and sign the informed consent form
  • Diagnosed with type 1 or 2 diabetes mellitus
  • Hemoglobin A1c (HbA1c) of less than 10% within 3 months
  • Clear media for adequate OCT and optical coherence tomography angiography (OCTA) images
  • Treatment-naïve DME diagnosed clinically
  • Central subfield thickness (CST) of >300μm and intra- or subretinal fluid seen on (spectral-domain) SD-OCT
  • Early Treatment Diabetic Retinopathy Study (ETDRS) BCVA between 24 and 73 letters on the day of randomization
  • Treatment within 12 months of DME diagnosis
  • No contraindication of vitrectomy or conbercept intravitreal injection

Exclusion criteria

  • Any previous DME treatment (i.e. anti-VEGF injections, intraocular corticosteroids, macular photocoagulation)
  • Macular edema caused by other disease (i.e. neovascular age-related macular degeneration, retinal vein occlusion, uveitis)
  • Any previous intraocular surgeries (cataract surgery performed at least 3 months before study entry will not be exclusionary)
  • Vision loss caused by other ocular disease (i.e. cataract, proliferative diabetic retinopathy, glaucoma, high myopia)
  • A follow-up duration of less than 12 months
  • Severe dysfunction of the heart, liver, kidney, lung and other organs

Treatment and study plan

Vitrectomy combined with ILM peeling

Procedure

Standard 25-gauge PPV will be performed by an experienced surgeon under retrobulbar anesthesia. After clearing the central vitreous, a complete posterior vitreous detachment (PVD) will be achieved with aspiration to remove the tightly attached posterior hyaloid. The vitreous will be removed by a high-speed vitrectomy surgical system (Constellation Vision System, Alcon Laboratories, Fort Worth, Texas, USA). The ILM stained with indocyanine green (ICG) will be peeled up to the vascular arcades. In case of need, panretinal photocoagulation (PRP) can be performed during surgery. The vitreous cavity will be filled with balanced salt solution (BSS) at the end of the procedure.

Conbercept intravitreal injection

Drug

Patients will receive three monthly intravitreal injections of 0.5 mg Conbercept (Chengdu Kanghong Biotech Co.) with a 30-gauge syringe needle approximately 3.5-4 mm posterior to the corneal limbus under topical anesthesia.

Primary outcomes

  1. Best corrected visual acuity change (BCVA)

    Time frame: 1, 3, 6, 12 month postoperatively

    Early Treatment Diabetic Retinopathy Study (ETDRS) Alphabet Chart

  2. Central subfield thickness (CST) change

    Time frame: 1, 3, 6, 12 month postoperatively

    Three-dimensional spectral domain optical coherence tomography (SD-OCT)

Secondary outcomes

  1. The stage of diabetic retinopathy (DR)

    Time frame: 12 month postoperatively

    The grading and classification of DR will follow the International Clinical Diabetic Retinopathy and Diabetic Macular Oedema Disease Severity Scales. Ultra-wide field fundus photography will help investigators grade diabetic retinopathy.

  2. Cost-effectiveness analysis

    Time frame: 12 month postoperatively

    The incremental cost-effectiveness ratio (ICER) is used as the evaluation index in cost-effectiveness analysis. The average cost of the two groups of treatments is taken as willingness to pay (WTP). If ICER is less than WTP, the treatment scheme is cost-effective.

  3. Vision-related quality of life questionnaire

    Time frame: 6, 12 month postoperatively

    The National Eye Institute Visual Functioning Questionnaire-25 (NEI-VFQ-25) will be used to evaluate the vision-related quality of life. Scores range from 0 to 100, and lower scores indicate a poorer quality of life.

  4. Biomarkers of optical coherence tomography (OCT)

    Time frame: 1, 3, 6, 12 month postoperatively

    Scanning was centred on the macular fovea with a scan length of 6 mm. The resolution was 5 μm, the scan depth was 4 mm, and the scan mode was horizontal linear scanning of 512×128.

  5. Biomarkers of OCT angiography (OCTA)

    Time frame: 1, 3, 6, 12 month postoperatively

    The scanning area, centred on the fovea, was captured in 3×3 mm sections with a resolution of 304×304 pixels.

  6. Occurrence rates of re-treatment

    Time frame: 12 months postoperatively

    Pro re nata conbercept treatment will be performed if the following criteria are met: (1) existence of recent or persisting cystoid retinal lesions; (2) a decrease of no less than 5 ETDRS letters in BCVA; and (3) an increase of 50 μm or more in CST compared with the best value previously achieved.

  7. Occurrence rates of adverse events

    Time frame: 12 months postoperatively

    Ocular hypertension, progression of cataract, corneal abrasion, retinal injury, hyphaemia, uveitis or inflammatory reaction, and endophthalmitis.

Study contacts

Contact information is provided by the study sponsor or research team.

Bojie Hu

CONTACT

[email protected]

13612130943

Sponsors and collaborators

Lead sponsor

Tianjin Medical University Eye Hospital

Other

Registry information

Important dates

Study start
2024
Primary completion
2025
Study completion
2026
First posted
Feb 15, 2023
Registry last updated
Mar 6, 2024

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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