Trypan Blue dye is very useful in cataract surgery because it can stain the anterior lens capsule which improves visualization for performing the capsulorhexis when we have a limited red reflex. The trypan blue dye is particularly useful in white cataracts where the lens is so opaque that there is an absence of a red reflex. But remember that the blue dye must come into direct contact with the anterior lens capsule.
We need to understand the differences between cohesive and dispersive viscoelastics and if you need a review of this, please see this prior post. Using a cohesive viscoelastic, which is more solid and tends to stick together cohesively, we can fill the anterior chamber and then create a small space just above the anterior lens capsule by injecting a few drops of balanced salt solution on top of it.
But for most cataract cases, we are using a dispersive viscoelastic at the beginning of the surgery because it will tend to coat and protect the corneal endothelium. Most of the dispersive viscoelastics in the USA market have the word coat in their names: Viscoat from Alcon, Ocucoat from B&L, and Healon endocoat from J&J. These OVDs (ophthalmic viscosurgical devices) will also coat the anterior lens capsule and prevent the trypan blue dye from staining it. In this video, we show that issue and also the solution to solve it.
Click below to learn why Trypan Blue dye should be used before a dispersive OVD: