First implantation of a Rayner monofocal intraocular lens with aspheric optics

Rayner is pleased to announce the implantation of the first Rayner C-flex^® monofocal IOL with an aspheric correction.

Surgery was performed by Mr. Charles Claoué (London, UK) with very encouraging results.

The Rayner C-flex^® Aspheric IOL (and the Superflex^® Aspheric IOL) are based on aberration-neutral optic technology.

Recent advances in IOL design have involved the application of wavefront technology to help improve optical efficiency and visual function. The ability to measure Higher Order Aberrations has led to a much greater understanding of the eye as an optical system, resulting in a new category of IOLs – aspherics – which are capable of providing an excellent quality of vision and improved contrast sensitivity particularly in mesopic illumination.

In the younger eye, the naturally-occurring positive spherical aberration of the cornea is largely balanced by the negative spherical aberration of the crystalline lens, resulting in optimal vision. However, with age, that negative spherical aberration becomes more positive, creating an imbalance which can reduce contrast sensitivity and thus, visual function. This compounds the reduced contrast sensitivity of the ageing macula.

Aspheric IOLs, unlike conventional IOLs (which have positive spherical aberration), induce significantly less spherical aberration by effectively avoiding adding to the positive spherical aberration of the cornea. As such, they are associated with an increased contrast sensitivity and functional visual acuity, particularly under mesopic and scotopic conditions. This can lead to an improved night vision and decreased glare. As contrast sensitivity tends to decline with age, aspheric IOLs can minimise loss of contrast sensitivity to optimal levels.

However, “aspheric” IOLs can either be based on negative spherical aberration designs (to try to correct existing corneal asphericity), or they can be truly aspheric, or aberration-neutral, to reduce the occurrence of additional and unwanted optical aberrations. There are concerns that IOLs with negative spherical aberrations may, by producing a very flat wave-front, have an undesirable effect on the depth of field. Rayner aspheric IOLs are spherically aberration-neutral with the aspheric modification being applied to the anterior surface of the IOL, providing uniform refractive power from the centre of the optic to its edge, for optimal visual outcomes. The depth of field of this lens is very similar to standard IOLs whilst having the advantages discussed above.

Additionally, unlike negative spherical aberration designs, aberration-neutral IOLs do not contribute to any pre-existing higher order aberrations in the visual axis, thereby optimising image quality, regardless of the patient’s idiosyncratic spherical aberration, or indeed, by any limitations imposed by previous surgery. Similarly, unlike negative spherical aberration designs, with aberration-neutral IOLs, the image quality is much less likely to be affected by decentration or tilt.

In addition to all these advantages, the Rayner C-flex^® Aspheric and Superflex^® Aspheric IOLs offer the technology of the existing IOL platform. These include the Amon-Apple Enhanced Square Edge for exemplary low posterior capsular opacification rates, AVH (anti-vaulting haptic) Technology for optimal centration, and a single-use disposable injector capable of IOL insertion through a sub 3mm incision.

Fifty seven years after the introduction of the IOL and in the centenary year of the birth of Sir Harold Ridley FRS, Rayner Intraocular Lenses is still at the forefront of IOL technology.