Objective: To investigate the 4-port pars plana vitrectomy in eyes with severe proliferative diabetic retinopathy (PDR).
Methods: It was a case-control study. Twenty-eight eyes in 27 patients with extensive fibrovascular proliferation associated with PDR were retrospectively collected, who were undergone 4-port pars plana vitreous surgery with bimanual manipulation techniques, such as membrane dissections and enbloc membranectomy. The control group consisted of 30 eyes in 30 patients with PDR which were undergone 3-port pars plana vitrectomy by the same surgeon.
Results: Twenty-eight eyes were undergone membrane dissection and enbloc membranectomy smoothly during 4-port pars plana vitrectomy, 2 iatrogenic holes occurred in 1 eye. During the follow up 7 months to 4.5 years, the retina was fully attached in all eyes, visual acuity had improved except 1 eye which complicated with neovascular glaucoma. In the control group, membranes partially remained in 2 eyes, 4 iatrogenic holes appeared in 3 eyes, neovascular glaucoma occurred in 3 eyes, the retina was reattached during the follow-up time from 12 to 34 months.
Conclusions: For severe proliferative diabetic retinopathy, the 4-port pars plana vitrectomy with bimanual manipulations of membrane peeling is safe and efficiency.