STAINING OF INTRAOCULAR LENSES WITH VARIOUS DYES:A STUDY OF DIGITAL IMAGE ANALYSIS

Abstract

Abstract: : Purpose: To evaluate the interaction of various intraocular lens (IOL) materials with commonly used dyes. Methods: One IOL of five groups (polymethyl methacrylate, silicone, three–piece hydrophobic acrylic, single–piece hydrophobic acrylic and single–piece hydrophylic acrylic) were bathed in trypan blue 0.1%, fluorescein sodium 2%, indocyanine green (ICG) 0.5% for 15 minutes. Digital photographs of the IOLs were obtained prior to bathing and after the 15–minute bath in each dye. The same IOLs were immersed in the same dye for another 15 minutes and digital images were reobtained to depict the 30–minute dye uptake. New IOLs from the group that exhibited visible colour change after the 15–minute bath, were then bathed in half–dilution and if there was still visible dye uptake, one step further dilution was performed, repeating the 15–minute bath and digital photography. The images were then processed using Adobe Photoshop 5.1 to get mean luminosity and red–green–blue values. These values were compared between the groups and the undyed controls. Also dye wash–out was observed in serum containing vials. Results: None of the PMMA, silicone and hydrophobic acrylic IOLs were stained with the dyes used. The only IOL material that changed colour was hydrophylic acrylic and did so with all dyes. Most marked colour change was with fluorescein sodium 2%, the least was with trypan blue 0.05 %. Two–fold dilution of trypan blue and four–fold dilutions of fluorescein sodium and ICG still stained the hydrophilic acrylic IOL, however four–fold dilution of trypan blue did not cause significant colour change. Trypan blue washed out within six hours while the IOL stained with ICG remained green for longer than 24 hours. Conclusions: Hydrophylic acrylic IOLs should be used with caution in cases which dyes are used since this material demonstrates marked dye uptake and also washout may take some time.

Keywords: imaging/image analysis: non–clinical • optical properties • clinical laboratory testing