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

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

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.

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

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