Heavy trypan blue staining of epiretinal membranes: an alternative to Infracyanine green

Background: By using dyes, it is easier to identify the extent of an epiretinal membrane (ERM) or the inner limiting membrane (ILM) during surgery. Trypan blue (TB) stains ERM and ILM weakly, but with less apparent toxicity than other intraocular dyes. Its main drawback in vitreoretinal surgery is the requirement of an air-fluid exchange (AFX) before its use. Aim: To propose a modified form of TB denser than water, thus obviating the need for an AFX. Design: A prospective, consecutive trial with heavy trypan blue in vitreoretinal surgery. Methods: A consecutive group of patients with ERMs was recruited prospectively. Patients were operated on using conventional methods. Heavy TB was prepared by mixing glucose 10% with Membrane blue (Dorc, Zuidland, The Netherlands) isovolumetrically. Patients were preoperatively and postoperatively assessed at 3 and 6 months (vision and ocular coherence tomography (OCT)). Ease of surgery was also assessed. Results: 29 eyes were included in the study. Reapplication of dye was necessary in 25% of the cases, leading to improved contrast further facilitating the peeling process. In no case was an AFX necessary to obtain sufficient staining. All patients with ERM had an improvement in vision (from median 0.30 to 0.55) and macular volume and foveal thickness (from median 450 to 238 mm) on OCT. No retinal detachment or other complications developed as a result of surgery. Conclusion: Heavy TB can be delivered efficiently to the retinal surface without an AFX. Staining was sufficient to allow a safe and efficient peeling of ERM. Repeat applications were easily performed. Its use was associated with vision improvement and decreased in foveal thickness, and the absence of adverse events in this small case series.