Determining the lowest trypan blue concentration that satisfactorily stains the anterior capsule

Purpose: To determine the lowest concentration of trypan blue that will stain the anterior capsule satisfactorily to perform a safe continuous curvilinear capsulorhexis and to describe a staining technique using a dispersive viscoelastic material. Setting: Cerrahpasa School of Medicine, University of Istanbul, Istanbul, Turkey, Methods: Trypan blue 0.1% (Vision Blue(R)) was diluted by half by adding an equal volume of balanced salt solution (BSS(R)) in a stepwise pattern continuously until the concentration failed to stain the anterior capsule satisfactorily. After the dilution, 4 concentrations of the dye were obtained: 0.050%, 0.025%, 0.0125%, and 0.00625%. The volume of dye used for staining was 0.1 cc at all concentrations. Each concentration of the dye was applied using a classic air-bubble technique or a technique in which the dye was injected under sodium hyaluronate 3.0%-chondroitin sulfate 4.0% (Viscoat(R)) onto the anterior lens surface without using an air bubble to reform the anterior chamber. Each diluted concentration was used in 10 eyes by the same surgeon, with 5 eyes having the air-bubble technique and 5 having the viscoelastic technique. The 0.1% concentration was used in 5 eyes, all having the viscoelastic technique. Results: Trypan blue in concentrations as low as 0.0125% stained the anterior capsule satisfactorily. In addition, staining was possible under the Viscoat. The viscoelastic technique was faster, safer, and easier to perform than the air-bubble technique. Conclusions: As trypan blue is a potentially carcinogenic vital dye and its possible long-term side effects are unknown, the lowest effective concentration should be used. A concentration lower than 0.1% was effective in staining the anterior capsule even under dispersive viscoelastic material. (C) 2002 ASCRS and ESCRS.