Purpose: To demonstrate whether indocyanine green stains the inner limiting membrane of the retina or residual vitreous cortex.
Methods: We report on the intraoperative staining patterns of the vitreomacular interface in 10 eyes of 10 consecutive patients who underwent vitrectomy with indocyanine green staining for macular hole formation and diffuse diabetic macular edema.
Results: In five eyes of five patients with macular holes, indocyanine green staining of the macula after posterior vitreous detachment resulted in an immediate visibility of a discernable membrane that was not previously seen. In five eyes of five patients with diffuse diabetic macular edema and adherent cortical vitreous, indocyanine green failed to stain the vitreomacular interface. After peeling off the residual vitreous cortex, however, a discernable membrane could be identified using indocyanine green dye again. Light and transmission electron microscopy revealed the inner limiting membrane as the membrane that had been stained and removed in all specimens.
Conclusion: Indocyanine green selectively stains the inner limiting membrane. Staining of the vitreomacular interface using indocyanine green as a vital dye enables the surgeon to distinguish between the residual vitreous cortex and the inner limiting membrane, and it allows safer and easier removal of the inner limiting membrane.