Indocyanine green staining during macular surgery

We stained the inner surface of macular retina with 0.5% indocyanine green (ICG) solution during vitreous surgery on 10 eyes of macular hole and 4 eyes of epimacular membrane. The ICG-stained membranes were excised and examined with transmission electron microscopy. The degree of staining observed during surgery was compared with histopathologic findings. In 7 eyes with stage 2, 3 or 4 macular holes, the inner surface of the central retina was homogeneously well-stained with ICG. In the other 3 eyes with stage 3 or 4 macular holes and in all 4 eyes with epimacular membranes, the inner surface of the central retina was poorly or irregularly stained with ICG. Histopathologically, the well-stained membranes showed internal limiting membrane (ILM) only. The poorly stained membranes showed either proliferated cells overlying the ILM or cellular proliferation alone. The findings show that staining of the retinal surface with ICG allows intraoperative identification of the ILM or epiretinal proliferation.