In vitro analysis of AcrySof intraocular lens glistenings in AcryPak and Wagon Wheel packaging

Purpose: To compare the formation of "glistenings in acrylic intraocular lenses (IOLs) packaged in Wagon Wheel and AcryPak(TM) packaging systems. Setting: John Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. Methods: Acrylic IOLs in Wagon Wheel (WW) and AcryPak (AP) packaging were analyzed in vitro. The lenses were placed in a test chamber with a controlled temperature and evaluated every 48 hours for 336 hours. The presence of glistenings within the lens optic was assessed using slitlamp evaluation and a quantitative microscopic evaluation with an image analysis system. Results: When maintained at a constant temperature, the WW packaged IOLs showed no glistening formation and the AP-packaged IOLs, significant glistening formation. Glistenings were noted in the WW-packaged IOLs only under fluctuating temperature conditions. Quantitative image analysis confirmed the presence of glistenings only in AP-packaged IOLs maintained-at a constant temperature. Conclusion: The glistenings in AcrySof(TM) IOLs were temperature dependent and confined to IOLs packaged in AcryPak folders and maintained at constant (body) temperatures. These findings are believed to be consistent with fluid formation within the acrylic optic, somehow related to the AcryPak packaging system.