Purpose.: To describe the intraoperative staining pattern of the internal limiting membrane (ILM)-specific dye Brilliant Blue G (BBG) in a cohort of patients with idiopathic macular holes; to analyze the associations of the staining pattern with pre- and postoperative variables and to correlate the staining pattern with transmission electron microscopy (TEM) of the excised ILM.

Methods.: Fifty-five consecutive patients were studied. The staining pattern was divided into three subtypes based on the intraoperative appearance. The presence of a narrow rim of nonstaining around the macular hole (MH) edge was noted and measured. In the final 21 patients, the excised ILM was examined with TEM.

Results.: The pattern of staining observed was categorized as uniform in 33 patients (60%), patchy nonstaining in 17 (31%), and no visible staining in 5 (9%). The staining pattern correlated with the MH stage. In the patients with uniform or patchy staining, a nonstaining rim was observed in 26 (52%) of the 50. The presence of a rim was associated with a greater hole diameter and lower postoperative visual acuity. The stain pattern correlated significantly with the amount of cellular tissue on the vitreous side of the ILM on TEM, with a greater proportion of multicellular layer membranes and new collagen in the incomplete staining groups.

Conclusions.: A variety of nonstaining patterns around macular holes can be observed using BBG, and these patterns correlate to the amount of cellular tissue on the vitreous side of the ILM seen histologically. These patterns could be used to guide the ILM peeling requirement or extent in future studies.