16 Advances in intraocular lens materials

Cataracts remain the leading cause of blindness worldwide despite the availability of new materials and designs for its treatment. Replacement of an opacified lens with a biomaterial-based intraocular lens (IOL), one of the first procedures to show the potential impact of biomaterials in the body, remains one of the most common surgical procedures performed. Current materials include hydrophilic acrylics, hydrophobic acrylics, and silicone-based materials. Despite advances in materials and designs, complications remain, the most common of these being posterior capsule opacification (PCO). This results from epithelial to mesenchymal transition, when lens epithelial cells, remaining in the capsular bag following lens explantation, transform to fibroblast cells, migrate to the posterior surface of the lens, and result in the formation of secondary cataracts. Square-edged designs have been shown to decrease the incidence of PCO. Additional experimental methods to alter the response to the IOL include delivery of various wound healing inhibitor and surface modification of the IOL or the haptic material. An additional limitation of current designs is the lack of accommodation, with the development of a true accommodating IOL being a future goal.