Epidemiological studies and clinical observations suggest that the incidence of diabetic macular edema (DME) in patients with severe PDR is up to 70%, which is one of the main causes of visual loss and even blindness in patients with DR

The treatment of DME mainly includes laser photocoagulation, glucocorticoid or anti-VEGF drug intravitreal injection therapy and vitreous surgery. However, pan-retinal photocoagulation (PRP) can result in limited peripheral vision, decreased night version and aggravate diabetic macular edema

Both glucocorticoids and anti-VEGF drugs can rapidly reduce macular edema (ME) and improve the visual function, but they all have a short duration of action and require repeated injections

Consequently, PPV with ILM peeling has been applied in the surgical treatment of fundus diseases, especially in macular hole (MH), ME, macular epiretinal membrane, retinal splitting and other tractive macular diseases. However, the efficacy of vitrectomy combined with internal limiting membrane stripping in the treatment of PDR with DME has rarely been reported

The purpose of this study was to evaluate the efficacy of preoperative intravitreal injection of ranibizumab combined with vitrectomy with internal limiting membrane peeling for macular edema on diabetic macular edema in severe proliferative diabetic retinopathy