Abstract
Purpose :
Posterior Capsule Opacification (PCO) is the most common complication associated with Intra Ocular Lens (IOL) implantation. It is believed that the interactions between IOL and lens Capsule (LC) may influence the extent of PCO formation. Specifically, a strong binding force between IOL and LC may impede lens epithelial cell migration and proliferation and thus reduce PCO formation. Unfortunately, current in vitro models cannot be used to assess the potential of PCO due to their failure to simulate the posterior curvature of the LC and IOL, a factor known to affect PCO pathogenesis in clinic. To overcome such a challenge, we have developed a new system to study IOL-LC interaction and thus to predict PCO.
Methods :
To better mimic PCO growth, a new in vitro model with simulated LC and a custom-designed micro-force tester is established. A method to fabricate simulated LCs was developed by imprinting IOL onto molten gelatin (low molecular weight, 3%, form Sigma) to create the simulated LCs with curvature resembling the bag-like structure that collapses on the IOL post implantation. By moving the LC mold down slowly, the bending bar attached to a custom-designed micro-force tester was able to measure the force required to detach IOL from simulated LC.
Results :
We have successfully fabricated this in vitro system, which allows us to measure the binding force reproducibly between IOL and lens capsule as low as ~ 0.1 mN. Using this system, we first tested the binding force of various IOLs with simulated LCs and observed binding forces on different commercially available IOLs in the following sequence: Acrysof (1.24 ± 0.24 mN) > Silicone (0.97 ± 0.05 mN) > PMMA (0.81 ± 0.09 mN). These results are in a perfect agreement with the clinical observations about PCO performance of the tested IOL in the following order (best to worst): Acrysof, Silicon, and PMMA. Our preliminary results also show that difference of binding forces can be increased by using collagen gels to create simulated LCs and also adding other critical extracellular matrix proteins, including laminin and fibronectin.
Conclusions :
An in vitro system has been established to assess the interaction between IOL and LCs. We believe that this system can provide valuable insight on the IOL:LC interplay and their relationship to the clinical PCO outcome.
This is a 2020 ARVO Annual Meeting abstract.