AIM: To further investigate the etiology and treatment strategies of diabetic macular edema(DME)by studying the correlation between responses to intravitreal injection of Ranibizumab(IVR)and diabetic retinopathy(DR)extent in DME patients.

METHODS: This study comprised 33 eyes of 27 non proliferative diabetic retinopathy(NPDR)patients with DME and 34 eyes of 32 PDR patients with DME, who had been followed for at least 6mo after IVR. We compared the responses to the anti-VEGF treatment between the two groups.

RESULTS: NPDR patients had strong statistical improvement in best corrected visual acuity(BCVA)and central macular thickness(CMT)after both 3-month treatment and 6-month treatment(P<0.05), While PDR patients had not(P>0.05). There were also statistical differences(P<0.05)in BCVA and CMT between NPDR group and PDR at a time when the patients had received both 3-month treatment and 6-month treatment.

CONCLUSION: Different extents of DR have influence on DME responses to anti-VEGF.