Long-Term Implant Cytology Evaluation of Explanted Intraocular Lenses Manufactured from Different Materials

Purpose: To evaluate long-term cell deposition on the surface of intraocular lenses (IOLs) made from different materials, focusing on late foreign-body inflammatory responses. Setting: John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. Design: Experimental Study. Methods: IOLs explanted as part of standard of care were received in our laboratory immersed in fixative. Patient demographics, implantation and explantation dates, reasons for explantation, as well as IOL model and manufacturer were obtained. Lenses underwent gross and light microscopic evaluation without previous staining; those explanted 2 or more years after implantation underwent implant cytology staining (hematoxylin/eosin staining) to assess for the presence of cell deposits, as well as proteinaceous deposits on their anterior optic surface. Results: This study included 31 poly(methyl methacrylate) (PMMA), 58 hydrophobic acrylic, 40 hydrophilic acrylic, and 31 silicone IOLs explanted 21.51 +/- 6.55, 10.53 +/- 4.74, 7.41 +/- 3.67, and 10.73 +/- 4.31 years after implantation, respectively. Main reason for explantation was dislocation, followed by optic opacification (of hydrophilic acrylic IOLs). Giant cells were observed in 9 PMMA and 6 hydrophobic acrylic lenses, with many cases related to rough surfaces of positioning holes, multiple Nd:YAG laser pits, as well as recent history of secondary surgery. Proteinaceous material was estimated to cover 22.52 +/- 19.42%, 22.71 +/- 15.82%, 5.52 +/- 7.43%, and 6.53 +/- 5.85% of the anterior optic surface in these four groups. Conclusion: This study showed that inflammatory cell deposits are rarely observed on IOLs explanted more than two years after implantation.