Biomechanical performance of expanded polytetrafluorethylene sutures, flanged polyvinylidene fluoride and polypropylene in scleral IOL fixation.

To compare the least required dislocation force (LRDF) among three scleral fixation techniques used for secondary intraocular lens (IOL) implantation. The flanged haptic technique (FFT) with a 3-piece IOL, the double-flange technique (DFT) and the Expanded Polytetrafluoroethylene suture fixation technique (GFT) with a four-loop haptics IOL. In this ex-vivo laboratory study, twenty human corneoscleral tissues (CSTs) were prepared, and all three fixation techniques were performed on each CST at standardized scleral positions. FFT was performed using a three-piece IOL with polyvinylidene fluoride (PVDF) haptics, whereas DFT and GFT were applied to a four-loop haptic IOL using either melted polypropylene flanges (DFT) or Expanded Polytetrafluoroethylene sutures (GFT). Mean LRDF differed significantly among techniques, with 0.73 ± 0.54 N (N) for DFT, 1.09 ± 0.48 N for FFT, and 3.95 ± 0.55 N for GFT. No significant difference was found between DFT and FFT (p = 0.221). In contrast, GFT demonstrated significantly higher LRDF compared with both DFT (p < 0.001) and FFT (p = 0.042). Among the evaluated fixation methods, GFT provided the highest resistance to longitudinal dislocation forces in this ex-vivo model, while DFT and FFT demonstrated comparable biomechanical stability. These findings highlight substantial differences in mechanical resilience across fixation techniques.