Severe Proliferative Diabetic Retinopathy

The utility and practice of Panretinalphotocoagualtion (PRP) in patients with high-risk Proliferative Diabetic Retinopathy (PDR) have not changed since the ETDRS reported guidelines in 1987. A meta-analysis of the DRS and ETDRS two large U.S. RCT of laser therapy for PDR confirmed the effectiveness of PRP (Level I evidence). Both trials had large sample sizes, excellent compliance and adequate follow-up. These studies established that PRP reduces the risk of severe visual loss in patients with high-risk PDR by 50% to 60%20.

With the arrival of the vitrectomy, this surgery was often used to treat eyes with severe complications from PDR. The most common indications for vitrectomy were nonclearing vitreous hemorrhage, Tractional Retinal Detachment(TRD) with macular involvement, and combined traction and rhegmatogenous retinal detachment. With the addition of new indications to the known indications vitrectomy has been performed in earlier stages(severe PDR). A large number of case series reports have assessed the effect of pars plana vitrectomy on diabetic TRD with or without macular detachment but the level of evidence was low and they included patients not homogeneous. These studies have generally shown benefit, with improved vision seen in many patients (ranging from 22% to 65%) but they have also indicated a high rate of operative and postoperative complications. These numerous intra and post-operative complications could lead to satisfying anatomical results but poor vision.The purpose of this study is to examine and compare, prospectively, best corrected visual acuity (BCVA) outcomes and complications of a cohort of patients with Proliferative Diabetic Retinopathy and Tractional Retinal Detachment not involving macula undergoing pars plana vitrectomy (PPV) or conventional management (panretinal photocoagulation)

Inclusion criteria

• Eyes with advanced Proliferative diabetic retinopathy some with TRD not involving the macula. The definition of severe PDR included eyes with extensive, active neovascular and fibrovascular proliferation graded using Modified Airlie House Classification

Exclusion criteria

• Eyes with fibrovascular tractional detachment involving the macula were excluded. Eyes with a combined tractional and rhegmatogenous retinal detachment and eyes with a history of uveitis or trauma, with previous vitrectomy and neovascular glaucoma were also excluded.