Negative staining of the vitreous with the use of vital dyes

The vitreous cortex, epiretinal membrane (ERM), and inner limiting membrane (ILM) are transparent tissues and are thus difficult to visualize. Staining these structures can increase the efficiency of a nontraumatic removal.

The surgeon performs a partial core vitrectomy and induces a posterior vitreous detachment. The vital dye is then injected into the retrohyaloid space in balanced salt solution (BSS). The dyes used are TWIN (Alchimia srl, Padova, Italy), MembraneBlue-Dual (DORC International, Zuidland, the Netherlands), and Doubledyne (Alfa Intes, Casoria, Italy). The surgeon can complete the vitrectomy and gradually aspirate the dye with the probe. Once the vitrectomy is complete, the surgeon can perform the peeling of the ERM without the need to reinject the vital dye over the macula.

The presence of the dye over the macula facilitates visualization of the vitreous cortex by blocking the red reflex and increasing the contrast power of the coaxial light probe during the vitrectomy. This allows a negative coloration of the vitreous because the dye acts by increasing the visibility of the surrounding BSS and not the vitreous itself.

We describe a new chromovitrectomy technique using the same dye to increase the visualization of the vitreous, posterior hyaloid, ERM, and ILM.