To evaluate the efficacy of internal limiting membrane (ILM) removal during vitrectomy in proliferative diabetic retinopathy (PDR) patients.

Seventy-four eyes of 74 PDR patients who underwent vitrectomy were enrolled. All patients had been followed for at least one year. Thirty-three patients who underwent vitrectomy without ILM peeling from January 2004 to February 2005 were assigned to Group A and 41 patients who underwent vitrectomy with ILM peeling from March 2005 to October 2005 were assigned to Group B. Visual acuity (LogMAR), central macular thickness measured by optical coherent tomography (OCT), and presence or absence of macular edema were compared between the two groups at six months and one year after surgery.

Postoperative mean best corrective visual acuity (BCVA; LogMAR) were improved significantly in both groups at six months and one year after surgery. However, the overall amount of improvement in vision was not different between the two groups. The mean central forveal thickness in Group B was significantly thinner than in Group A at six months and one year after surgery. There was no difference between the two groups in macular edema incidence at that time. There were no serious complications in Group B by one year after surgery.

There was no difference in visual acuity between the Group A and Group B However, the central forveal thickness measured by OCT was thinner in the ILM peeling group, and there were no serious complications in ILM peeling group. Routine ILM peeling during vitrectomy in PDR will help to maintain the structural stability of the macula postoperatively.