Pars plana vitrectomy for diabetic fibrovascular proliferation with and without internal limiting membrane peeling

To evaluate the anatomical and functional results of internal limiting membrane (ILM) peeling during pars plana vitrectomy for fibrovascular proliferation (FVP) in diabetic retinopathy.

The study was a prospective comparative case series in design. Patients undergoing pars plana vitrectomy for mild to moderate diabetic FVP were divided into either Group 1: vitrectomy only, or Group 2: further ILM peeling in the macular area. Best-corrected visual acuity, fundus examination, and optical coherence tomography (OCT) were conducted at 3 and 6 months postoperatively.

There were 26 eyes of 25 patients in Group 1 (non-ILM peeling) and 23 eyes of 22 patients in Group 2 (ILM peeling). At 6 months postoperatively, OCT-identifiable epiretinal membrane (ERM) was found in 10 of 26 eyes (38.5%) in Group 1and 0 of 23 eyes in Group 2 (P=0.001) and six eyes (23.1%) in Group 1 developed biomicroscopic ERM, whereas no patients in Group 2 had ERM (P=0.02) at 6 months. OCT identifiable ERM correlated significantly with central macular thickness (r=-0.58, P<0.001), the presence of intraretinal cystic space (r=0.60, P<0.001), and fovea depression reappearance (r=0.36, P=0.008). Factors associated with poor visual outcome were macular detachment (P<0.001) and non-ILM peeling (P=0.004).

This pilot study suggests that ILM peeling during vitrectomy for diabetic fibrovascular proliferative membranes may minimize postoperative ERM formation and improve visual prognosis.