Sequential epiretinal membrane removal with internal limiting membrane peeling in brilliant blue G-assisted macular surgery

Purpose To assess the selectivity of brilliant blue G (BBG)
staining by analysing the morphological components of unstained and
stained tissue obtained during epiretinal membrane (ERM) removal
with internal limiting membrane (ILM) peeling in BBG-assisted
macular surgery. Methods Twenty-six surgical specimens were removed
from 13 eyes with epiretinal gliosis during vitrectomy using BBG
for ERM and ILM peeling. We included eyes with idiopathic macular
pucker, idiopathic macular hole and vitreomacular traction
syndrome. The dye was injected into the fluid-filled globe.
Unstained and stained epiretinal tissue was harvested consecutively
and placed into separate containers. All specimens were processed
for conventional transmission electron microscopy. Results The
first surgical specimen of all eyes showed no intraoperative
staining with BBG and corresponded to masses of cells and collagen.
The second surgical specimen demonstrated good staining
characteristics and corresponded to the ILM in all patients
included. In seven eyes, the ILM specimens were seen with minor
cell proliferations such as single cells or a monolayer of cells.
Myofibroblasts, fibroblasts and astrocytes were present. In five
cases, native vitreous collagen fibrils were found at the ILM. In
six of the eyes, ILM specimens were blank. Conclusion Our
clinicopathological correlation underlines the selective staining
properties of BBG. The residual ILM is selectively stained by BBG
even when a small amount of cells and collagen adheres to its
vitreal side. To reduce the retinal exposure to the dye, the
surgeon might choose to remove the ERM without using the dye,
followed by a BBG injection to identify residual ILM.