Spectral domain ocular coherence tomography findings pre- and post vitrectomy with fibrovascular membrane delamination for proliferative diabetic retinopathy

Purpose To describe the intraretinal microstructure using serial spectral domain optical coherence tomography (SD-OCT) preceding and following pars plana vitrectomy and delamination of fibrovascular membranes in patients with proliferative diabetic retinopathy (PDR). Methods This retrospective, interventional case series includes 28 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). Results Pre-operative central macular thickness (CMT) was significantly correlated with the final post-operative LogMAR BCVA (Pearson’s coefficient r =0.89; P =0.001). The eyes were categorised into three 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 in group 0 ( n =9) from 1.13±0.75 preoperatively to 0.34±0.21 (Student’s t -test: P =0.06), in group 1 ( n =10) the BCVA improved from 0.88±0.56 to 0.58±0.31 (Student’s t -test: P =0.053) and in group 2 ( n =9) the BCVA improved from 1.64±0.53 to 1.53±0.75 (Student’s t -test: P =0.652). IS/OS integrity and ELM integrity at 3 months post operatively, were significantly and positively correlated with final BCVA (Pearson’s coefficient: r =0.83, P