Intravitreal ranibizumab injection procedure is simple and effective. In management of chronic DME there is no clear anatomical endpoint. Visual stability is the primary aim. Argon focal laser therapy can be the safe second choice. The combined therapy is successful and practical for chronic DME patients.

Settings and Design: Randomized clinical study

Subjects and Methods:

investigators randomly assigned 150 adults (the average age was 59.32 years ±2.79) with chronic diabetic macular edema involving the macular center for repeated ranibizumab injections (group A-75) or focal/direct argon laser after repeated ranibizumab injections (group B-75). The outcomes were the changes in visual acuity letter score and the central subfield thickness (CST) from baseline to one year. visual-acuity Letter score, and CST were analyzed with independent t-test and Mann Whitney-test. General linear model with multivariate analysis was used for visual acuity letter score, and CST in both groups.

Inclusion Criteria:

• focal maculopathy
• diffuse macular edema
• diffuse macular edema with ischemic changes

Exclusion Criteria:

• ischemic maculopathy that was associated with grades of non-proliferative changes, or capillary drop out zones presented in the periphery of the macula
• patients with history of stroke or transient ischemic attack
• hypersensitivity to ranibizumab or any component of the ranibizumab formulation
• uncontrolled glaucoma in either eye (intraocular pressure [IOP] >24 mmHg with medication)
• evidence of vitreomacular traction (in either eye)
• active proliferative diabetic retinopathy (study eye)

Data processed and saved in eye center in the college

A clinical trial design strategy in which parties involved in the trial, the investigator and participants, do not know which participants have been assigned which interventions. Type of masking include: double-blind masking.