Retinal nerve fiber layer thickness evaluation after trypan blue-assisted macular surgery

The purpose of this study was to evaluate retinal nerve fiber layer (RNFL) thickness changes in eyes undergoing trypan blue-assisted macular surgery using optical coherence tomography-3. This is a prospective noncomparative, interventional, and observational case series of 35 eyes of 35 consecutive patients (15 eyes with macular hole, 14 eyes with idiopathic macular pucker, and 6 eyes with tractional diabetic macular edema) who underwent pars plana vitrectomy and peeling of the epiretinal membrane and/or internal limiting membrane assisted with 0.1 mL of 0.15% trypan blue.

The quantitative analysis of the peripapillary RNFL by optical coherence tomography was performed before surgery and 6 months postoperatively in both eyes of the same patient. The main outcome measures were significant changes in RNFL thickness (overall and by quadrant).

Optical coherence tomography assessment of the macular status at 6 months postoperatively showed closure of all macular holes and improvement in foveal contour in all cases of macular pucker or most cases of diabetic macular edema. Dissociated RNFL at the area of internal limiting membrane removal was observed in 9 eyes. No statistical significant changes in the mean RNFL thickness overall or by quadrant were observed after surgery.

Trypan blue-assisted peeling of macular epiretinal membranes and/or internal limiting membrane does not induce significant changes in RNFL thickness as measured by optical coherence tomography-3. Internal limiting membrane peeling may induce visible changes of the inner retinal surface possibly because of microdefects on macular nerve fiber layers.