577nm Micropulse Laser Versus 532nm Subthreshold Laser Photocoagulation for Diabetic Macular Edema

Study Overview
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Brief Summary
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This randomized, parallel controlled, clinical-trial aims to evaluate the therapeutic efficacy and safety of 577nm micropulse laser photocoagulation for diabetic macular edema compared with 532 subthreshold laser photocoagulation.

Detailed Description
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To evaluate the efficacy of 577nm micropulse laser photocoagulation with grid/focal treatment for diabetic macular edema. To investigate influence of 577nm micropulse laser photocoagulation on structure and function of macula compared with 532nm subthreshold laser photocoagulation.

Official Title
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Pure Yellow (577nm) Micropulse Laser Versus 532nm Subthreshold Laser Photocoagulation for Diabetic Macular Edema:A Prospective, Randomized, Paralleled Clinical Trial

Conditions
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Diabetic Macular Edema

Intervention / Treatment
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* Device: 577-MPL
* Device: 532-SLP


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Aged >18 years Patients with diabetes mellitus type 2 Diagnosed as diabetic retinopathy with Clinical Significant Macular Edema Central retinal thickness(CRT) of more than 250μm as measured by optical coherence tomography (OCT) ETDRS visual acuity >19 letters (Snellen equivalent of 20/400 or better) No macular laser coagulation or surgery or medicine therapy of macular edema within the last 6 months Blood glucose was controlled steadily(HbA1c≤10%) Exclusion Criteria: Taking part in other clinical trial within 3 months Planning panretinal photocoagulation(PRP) within 3 months Performed cataract surgery in the last 3 months Accompanied with other retinal vascular disease that can lead to macular edema, for example branch retinal vein occlusion(BRVO),central retinal vein occlusion(CRVO) Accompanied with severe opacity of refractive media that maybe impact therapy and observation Accompanied with nystagmus Accompanied with some history that maybe interfere with result or increase the risk of patients

Ages Eligible for Study
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Minimum Age: 19 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: 577-MPL<br>577nm micropulse laser photocoagulation(577MPL) treatment to the macular area of retinal thickening with a focal or grid pattern | Device: 577-MPL<br>* Device for 577nm micropulse treatment of the diabetic macular edema with the following parameters:100 microns spot size,5% duty cycle of 0.2 seconds,power is tested on micropulse mode and then reduce power to 50% of visible<br>* Other names: 577nm micropulse laser photocoagulation treatment;|
| Active Comparator: 532-SLP<br>532nm subthreshold laser photocoagulation(532-SLP) treatment to the macular area of retinal thickening with a focal or grid pattern | Device: 532-SLP<br>* Device for 532nm subthreshold treatment of the diabetic macular edema, by decomposing a subthreshold short pulse, with 10 milliseconds, 100 microns, and power(100-1000mW) adjusted according to patient's diopter transparency and pigmentation<br>* Other names: 532nm subthreshold laser photocoagulation treatment;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change of Best Corrected Visual Acuity(BCVA) | Best Corrected Visual Acuity will be measured by standard Early Treatment Diabetic Retinopathy Study (ETDRS) protocol | 1 year | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in 10°retinal sensitivity | Retinal sensitivity will be measured by microperimetry | 1 year | 
| Change of fundus autofluorescence | Fundus autofluorescence will be evaluated for different patterns（normal, increased, and decreased）before and after treatment | 1 year | 
| Change of Central Retinal Thickness(CRT) | Central Retinal Thickness will be performed by optical coherence tomography(OCT) | 1 year | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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micropulse, diabetic macular edema, laser, subthreshold