Vitrectomy with fibrovascular membrane delamination for proliferative diabetic retinopathy with or without preoperative Avastin

Purpose To describe and compare 1. the changes in intraretinal microstructure using serial spectral domain optical coherence tomography (SD-OCT) preceding and following pars plana vitrectomy and delamination of fibrovascular membranes and 2. Intraoperative and postoperative complications in patients with proliferative diabetic retinopathy (PDR) who had preoperative Avastin (group A) or not (group B). Methods This retrospective, interventional case series includes 113 eyes. Outcome measures included LogMAR distance best-corrected visual acuity (BCVA), SD-OCT integrity of photoreceptor inner and outer segments junction (IS/OS), and integrity of external limiting membrane (ELM), intraoperative and postoperative complications. Results Pre-operative central macular thickness (CMT) was significantly correlated with the final post-operative LogMAR BCVA in group A. Both groups were also categorised into three sub-groups based on post-operative IS/OS integrity (group 0: IS/OS intact; group 1: IS/OS irregular but not completely disrupted; group 2: IS/OS completely disrupted). Mean BCVA improved significantly and IS/OS integrity and ELM integrity postoperatively, were significantly and positively correlated with final BCVA in group A. Intraoperative complications such as iatrogenic tears and haemorrhage and postoperative such as vitreous haemorrhage and neovascular glaucoma where significantly less in group A compared to group B. Conclusions Pre-operative Avastin reduces the risk of intraoperative and postoperative complications and results in better postoperative anatomic and functional outcomes in fibrovascular delamination surgery for patients with PDR.