Time course of lens capsule staining using trypan blue and indocyanine green: in vitro study in porcine eyes

To determine whether staining of the lens capsule with trypan blue 0.1% and indocyanine green (ICG) 0.5% diminishes with time and whether it differs between the anterior and posterior capsules.

Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan.

Crystalline lenses removed from porcine eyes were stained for 10 seconds with 0.1 mL of trypan blue 0.1% or indocyanine green 0.5%. They were then placed in distilled water and observed for the persistence of staining over time. In a second experiment, the anterior chamber and internal aspects of the anterior capsule and internal and vitreous aspects of the posterior capsule were gently irrigated with 0.1 mL of trypan blue 0.1% or ICG 0.5%. After 10 seconds, the capsules were irrigated with distilled water and the staining intensities were compared.

Staining was not diminished 30 seconds, 5 minutes, or 1 hour after application of either dye. No difference was evident in staining intensity or diminution with time between the anterior and posterior capsules, but the external aspects were stained more than the internal aspects with both dyes. Trypan blue produced more intense staining than ICG.

Since the intensity of capsule staining in the intact lens did not change during a 1-hour immersion in water, capsule dyes may not dissipate fully during cataract surgery. As possible long-term adverse effects have not been ruled out, capsule dyes should be used in a low concentration for a short exposure time.