A modified technique for sulcus placement of glaucoma silicone tubes is described. Sulcus placement can be useful in patients with penetrating keratoplasty or in those who are at risk for corneal endothelial decompensation. However, correct placement can be difficult to confirm with a traditional ab externo approach. An ab interno technique for sulcus placement of glaucoma tube implants that both offers an easier approach and facilitates accurate positioning is described.