Trypan blue- and indocyanine green-assisted epiretinal membrane surgery: clinical and histopathological studies

To evaluate the clinical outcome and electron microscopic findings of trypan blue (Tb) and indocyanine green (ICG) assisted epiretinal membrane (ERM) surgery.

This is a prospective consecutive noncomparative interventional case series. After pars plana vitrectomy, 0.1 ml of 0.6 mg/ml Tb solution was applied for 1 min under air for ERM staining. After ERM removal, internal limiting membrane (ILM) was further peeled after staining with 0.2 ml of 1 mg/ml ICG solution. Intraoperative specimens were sent for electron microscopy. Tb was considered useful if the edge of ERM was stained where peeling could be initiated with a clearer visualisation of the overall extent of the ERM.

In all, 16 eyes from 16 patients were recruited. There were nine grade 1 ERMs, five grade 2 ERMs, and two grade 3 ERMs. Tb was useful in six (67%) of the nine eyes with grade 1 ERMs and in all eyes with grade 2 or 3 ERMs. The three remaining grade 1 ERMs were removed together with surrounding ILM that was stained by ICG. The mean line of improvement was 1.3 lines with the median BCVA improved from 6/12 to 6/9. All 16 eyes had symptomatic improvement and none developed ERM recurrence. No complication related to Tb or ICG was observed clinically or angiographically. Electron microscopy of the Tb-stained ERM specimens showed fragments of ILM in all specimens.

Tb and ICG are useful intraoperatively to improve the visualisation and facilitate complete removal of ERM and ILM in macular ERM surgery.