Brilliant blue G assisted macular surgery: the effect of air infusion on contrast recognisability in internal limiting membrane peeling

Abstract

Background To evaluate the potential efficacy and safety of inner limiting membrane (ILM) staining with brilliant blue G (BBG) under air infusion. Methods 63 patients, treated by one surgeon with macular hole or idiopathic epiretinal membrane were evaluated prospectively. BBG was applied under air infusion in 38 patients (group 1), and injected into the vitreous cavity in 25 (group 2). Main outcome measures were the chromaticity difference between the stained ILM and the unstained underlying retina, anatomical-functional outcomes and complications of the surgery. Chromaticity difference was measured by an objective and quantitative analysis method to describe colour contrast strengths as they are perceived by the human eye. Anatomical and functional outcomes were assessed using optical coherence tomography (OCT), visual field analyses (VFA) and multifocal electroretinography (mfERG). Results CIELAB scores showed a significantly superior contrast for group 1 (16.72 +/- 2.36) than group 2 (10.34 +/- 1.29) (p<0.001). Visual acuity had increased in 28 eyes and remained stable in 10 eyes in group 1. In group 2, visual acuity had improved in 17 patients and remained unchanged in 8 patients. Based on postoperative OCT, anatomical success rate was 100%. During the follow-up period, mfERG and VFA demonstrated no case of BBG toxicity in either group. Cataract progression was the main postoperative complication (six eyes in group 1 and four eyes in group 2) and did not show a significant difference between the groups (p=0.45). Conclusions BBG under air infusion yields a significantly higher contrast staining and easy peeling of ILM associated with anatomical and functional improvement and no retinal toxicity after macular surgery.