Objective:To retrospectively review the clinical outcome of pars plana vitrectomy(PPV) for patients with proliferative diabetic retinopathy(PDR).Methods:Data of 242 patients(288eyes) at Beijing Tongren Eye Center from 2002 to 2006 were retrospectively reviewed.According to the B-mode ultrasonic observation before surgery and ocular fundus during surgery

the reviewed cases were divided into four groups: vitreous hemorrhage but without retinal detachments

extensive fibrovascular vitreous membranes with limited traction retinal detachment but not involving the macular area

traction retinal detachment involving the macular

and combined phacoemusification and PPV.Results:Visual improvements were as follows: 84.9% in the group of patients with vitreous hemorrhage without retinal detachments(groupⅠ)

81.1% in the group of patients with extensive fibrovascular vitreous membranes with limited traction retinal detachment but not involving the macular area(groupⅡ)

41.9% in the group of patients with traction retinal detachment involving the macular(groupⅢ)

and 72% in the group of patients with combined phacoemusification and PPV(groupⅣ).The visual improvement between groupⅠ and groupⅡ had no statistical difference through χ2 test(χ2=0.529

P=0.467)

while the visual improvement difference of group

Ⅱand Ⅳ had statistical significance(P=0.000 1

0.000 1

0.016 respectively).Conclusion:Pars plana vitrectomy is an effective treatment for PDR and the treatment may acquire an ideal vision prognosis as the macular area is not obviously involved.