Elimination Kinetics of Indocyanine Green (ICG) Dye after Intraovular Surgery Using ICG Staining

Abstract

Abstract: : Purpose: To study the elimination kinetics of indocyanine green (ICG) dye after intraocular surgery using ICG staining techniques. Methods: Nine eyes in 7 patients with white cataract and 14 eyes in 14 patients with macular holes were studied. The intraocular fluorescence of ICG dye was observed using the ICG angiographic mode of a scanning laser ophthalmoscope(SLO) (in vivo), and fluorescence microscopy (in vitro) to determine the level of ICG after capsule-staining circular curvilinear capsulorhexis (ICG-CCC) during cataract surgery and internal limiting membrane (ILM) peeling with ICG ILM-staining during macular hole surgery (ICG-ILMrhexis). Results:SLO showed fluorescence in the anterior capsule of cataract patients on the first postoperative day, and the fluorescence continued for 6.0 ± 2.2 days after surgery. SLO also showed fluorescence in the disc and retina of macular hole patients, and it remained for 2.7 ± 1.4 months after surgery. Fluorescence microscopy revealed fluorescence of entire tissues suggesting that the dye had stained not only the surface of the membranes but also entered them. Conclusions:ICG dye exited the eye within approximately one week after ICG-CCC, but ICG dye remained in the eye for several months after ICG-ILMrhexis. Since entire tissues were stained in both cases, the difference in the kinetics of the dye might be caused not only by differences in stainability but also by other factors, such as the environment surrounding the tissues and/or molecular structural differences between the lens capsule and ILM. Although we found complete clearance of fluorescence and good visual outcomes during the observational period, the longer resident time of the dye after ICG-ILMrhexis may suggest a potential risk to the retina and optic nerve.

Keywords: macular holes • cataract • vitreoretinal surgery