This study investigates the hypothesis that ranibizumab injection given into the eye is a safe, efficacious and helping treatment option applied before surgical intervention of the proliferative diabetic retinal eye disorder.

This is a randomized, double blinded , controlled, two-center study assessing the feasibility, efficacy and safety of intravitreal ranibizumab injection applied as a preoperative adjunct treatment before vitrectomy surgery in severe proliferative diabetic retinopathy (PDR). Comparator arm consists of patients receiving standard vitrectomy alone with sham intravitreal injection preoperatively.

Inclusion Criteria:

• male or female 18 or older who have signed an informed consent
• Type I or II diabetes mellitus and severe proliferative retinopathy with tractional retinal detachment, tractional-rhegmatogenous retinal detachment, tractional detachment complicated with vitreous haemorrhage or active severe proliferative retinopathy not responding to previous panretinal laser photocoagulation
• study eye BCVA must have at least light perception and must not exceed 70 letters using ETDRS at testing distance 4 meters
• study eye vision decrease must be resulted from severe PDR

Exclusion Criteria:

• Active ocular inflammation or infection
• History of uveitis
• Uncontrolled glaucoma
• High myopia
• Any concurrent intraocular condition in the study eye that in the opinion of the investigator could confound the study results
• Former treatment with anti-angiogenic drugs within 30 days preceding Day 1 in the study eye
• History of vitrectomy within 60 days preceding Day 1 in the study eye
• History of intraocular surgery within 30 days preceding Day 1 in the study eye
• Untreated diabetes mellitus
• Severe hypertension (systolic pressure higher than 160mmHg)
• Current use of systemic medications known to be toxic to the retina
• History of thromboembolic events (incl MI and stroke) within 5 years
• Major surgery within previous 3 months or planned within the next 28 days
• Known coagulation abnormalities or current use of anticoagulative medications other than aspirins
• Known hypersensitivity to ranibizumab or any component of it
• Women of childbearing potential unless 2 methods of birth control applied
• Pregnant or lactating women