The aim of this study is to evaluate the one-year visual outcome and prognostic factors after intraocular injections of ranibizumab under pro re nata treatment regimen for the patients with diabetic macular edema (DME).

The aim of this study is to evaluate the one-year visual outcome and prognostic factors after intraocular injections of ranibizumab under pro re nata treatment regimen for the patients with diabetic macular edema (DME). Mean change of logarithm of the minimal angle of resolution (logMAR) visual acuity (VA), central foveal thickness (CFT), as well as predictive factors including best-corrected visual acuity (BCVA) were assessed.

Inclusion Criteria:

• 1) patients (aged>18 years) with DME who had a best-corrected visual acuity (BCVA) between 20/32 and 20/200, and CRT≥300μm; 2) clinically significant DME confirmed by both fundus fluorescein angiography (FFA) and optical coherence tomography (OCT) (Spectralis HRA+OCT; Heidelberg Engineering, Germany); 3) decreased vision caused by foveal thickening from DME, which could not be explained by any other cause.

Exclusion Criteria:

• 1) previous anti-VEGF or laser treatment; 2) proliferative diabetic retinopathy who required immediate panretinal photocoagulation; 3) active proliferative diabetic retinopathy; 4) other causes for macular edema, for example, branch retinal vein occlusion; 5) other causes of visual loss in the study; 6) unstable systemic conditions, for example, uncontrolled blood pressure, stroke, renal or kidney failure.