Trypan blue staining of the anterior capsule: the one-drop technique.

Capsule staining is usually a two- or three-stage procedure in which trypan blue is injected under air, a viscoelastic device, viscoelastic mixed with dye, or compartmentalized viscoelastic and balanced salt solution. In these techniques, the consequent irrigation of the anterior chamber with balanced salt solution may lead to a less stable anterior chamber, a decrease of pupil diameter, and damage of the corneal endothelium. A modification of current injection techniques for staining the anterior capsule under a dispersive viscoelastic device with 1 drop of trypan blue by an ordinary 27-gauge anterior chamber cannula is described.