Enhanced Square Edge Technology - Reducing PCO

Courtesy of David J Apple MD,
an SEM study of the fine surface
finish on the haptic-optic junction
of a Rayacryl® lens with the
new edge.

Reducing PCO

The Amon-Apple Enhanced Square Edge is a unique Rayner design (patent pending) which reduces Posterior Capsular Opacification (PCO) by creating an insurmountable physical barrier to cell migration.

In co-operation with Professors David Apple and Michael Amon, Rayner identified that all modern single-piece IOLs have a weakness at the haptic-optic junction: the so-called Achilles’ Heel of most single-piece injectable IOL designs, where there is no square edge and thus an incomplete barrier to PCO.

With the Amon-Apple Enhanced Square Edge, Rayner injectable IOLs have increased defence against PCO with 360° protection. Rayner’s own proprietary hydrophilic acrylic co-polymer, Rayacryl®, is already associated with low PCO and therefore fewer Nd:YAG capsulotomies – now, Rayner’s Enhanced Square Edge Technology reduces PCO to a minimum.

In competitor IOLs, the conventional Square Edge can contribute to dysphotopsia. In Rayner IOLs, ray-tracing studies show no general increase in glare as a result of Enhanced Square Edge Technology. This is attributable to the low refractive index of Rayacryl® (1.46). The value is sufficiently high to allow a suitable lens thickness with square edge but not so high as to create internal reflection that leads to dysphotopsia. There is a greater risk of glare with the hydrophobic acrylic biomaterials than with hydrophilic acrylic biomaterials because of the higher refractive indices of hydrophobic biomaterials. The problem of glare is frequently compounded by the optical impurity of some hydrophobic biomaterials which may contain vacuoles and glistenings.