Injecting Trypan blue under the iris: Staining in Small Pupils
In cases with posterior synechiae and a non-dilating pupil, the traditional “drop from above” method for Trypan Blue often fails to provide an adequate view of the anterior capsule. If you can’t see the capsule, you can’t safely perform the rhexis. This video demonstrates a clever maneuver: using a Surgical Peripheral Iridotomy (PI) as a portal for visualization. By performing a small, peripheral iridotomy, we create a direct channel to the posterior chamber. We then inject the Trypan Blue dye directly behind the iris. This ensures the dye reaches the entire anterior capsule surface, even the areas hidden by a miotic pupil or synechiae.
Strategic Steps for Success:
- The PI Portal: Use micro-scissors or a vitrector to create a small, peripheral opening. This serves as your “peek-hole” for both dye and OVD.
- Controlled Staining: Inject the dye under the iris slowly. Watch as the blue wave spreads beneath the pupil, providing a high-contrast roadmap for your capsulorhexis.
- Synechiolysis: Once stained, you can more safely use a cyclodialysis spatula or iris hooks to break the adhesions, knowing exactly where the capsule plane lies.
Have you tried this technique? Or does it make more sense to just open the pupil and then stain?
