Age-related cataract is the main cause of impaired vision in the elderly population
worldwide. In the UK, more than half of people who are over 65 have some cataract development
in one or both eyes. The only treatment that can restore functional visual ability is
cataract surgery where the opacified crystalline lens is removed by phacoemulsification and
an artificial intraocular lens is implanted. It is estimated that around 10 million cataract
operations are performed around the world each year. Cataract operations are generally very
successful, with a low risk of serious complications. The most common risk is developing a
condition called posterior capsule opacification (PCO), which causes impaired vision to
During the past two decades, cataract surgery underwent tremendous change and modernisation
resulting in today's small incision phacoemulsification surgery and a safe technique with a
short rehabilitation time for the patient. The most frequent long-term complication of
cataract surgery remains to be posterior capsule opacification (PCO). In the past few years,
refinements in surgical technique and modifications in IOL design and material have led to a
decrease in the incidence of PCO.
It has been shown that a sharp posterior optic edge inhibits migration of lens epithelial
cells (LEC) behind the IOL optic and therefore have a lower incidence of posterior capsule
opacification (PCO). Most IOL designs have open-loop haptics that are connected to the optic
towards the end of the production process, also called multipiece designs.
For several reasons such as better ease of use with injector systems and higher efficiency in
the production process, companies have developed IOLs with open-loop haptics out of one block
of material, also called single-piece designs. In the case of such single-piece IOLs, the
haptics tend to be much thicker than with multipiece IOLs. A potential drawback of the thick
haptics maybe an incomplete closure of the capsule at the optic rim with a reduced bending
effect of the posterior capsule around the posterior optic edge. Additionally, the posterior
sharp edge is often discontinuous in the region of the haptic-optic junctions. These
locations may serve as a scaffold for LECs to migrate behind the IOL optic resulting in PCO.
Nowadays a multitude of different single piece IOLS are available, many of them similar but
of course with some differences in regard to the chemical composition of the acrylic material
and the IOL design.
The purpose of this study is to compare the intensity of posterior capsule opacification
(PCO) between two different 1-piece foldable hydrophobic acrylic intraocular lenses (IOLs)
with different design of the sharp posterior edge within a follow up period of three years.