PCO prevention with IOLs maintaining an open or expanded capsular bag

Abstract

Postoperative capsular opacification is a multifactorial physiological consequence of cataract surgery. Opacification may involve the anterior or posterior capsules and may have a significant impact on visual function. Capsular opacification, composed of cortical/pearl and/or fibrotic components, can disrupt the proper functioning of an intraocular lens, particularly specialized ones such as accommodating lenses. It has been hypothesized that intraocular lens designs that maintain an open or expanded capsular bag are associated with better bag clarity. This may be due to mechanisms that include mechanical compression of residual lens epithelial cells within the capsular bag by a relatively bulky device/intraocular lens with overall inhibition of residual lens epithelial cells metaplasia and migration/proliferation of these cells. Another factor may be the mechanical stretch of the bag at the level of the equatorial region, maintaining the overall bag contour. Lastly, constant irrigation of the inner capsular bag compartment by the aqueous humor may also have an influence on the prevention of proliferation of residual cells. This chapter discusses devices that have been designed to minimize or prevent the development of anterior and/or posterior capsule opacification. Devices described include capsular rings and different designs of intraocular lenses which are intended for implantation within the capsular bag after phacoemulsification. The commonality among these devices is to maintain an open or expanded capsular bag, which effectively prevents capsular opacification. While some of the devices are already in clinical use, others are currently under investigation in animal studies.