BACKGROUND: The morphologic features and clinical consequences of removing residual optic disc stalks during vitrectomy for complications of diabetic retinopathy have not been described. METHODS: Twenty-four residual optic disc stalks that were surgically removed from eyes with proliferative diabetic retinopathy and dense nonclearing vitreous hemorrhage and/or traction retinal detachment were studied histologically using conventional hematoxylin and eosin staining as well as a modified Glees staining technique. RESULTS: Histologic examination demonstrated that 79% of the specimens consisted of vascularized glial tissue with an infiltrate of mononuclear cells and 21% consisted of glial membranes devoid of vasculature. Axons were identified in 33% of all tissues studied. Intra-operative hemorrhage occurred in three eyes with strongly adherent optic disc stalks and was controlled with transient elevation of the intraocular pressure. The presence of axons in the removed optic disc stalks was not correlated with a decreased final postoperative visual acuity (median time to follow-up 21 months). CONCLUSIONS: Residual optic disc stalks removed during vitrectomy for proliferative diabetic retinopathy frequently contained axons. The presence of axons does not portend an unfavorable postoperative visual outcome.