New technologies in the service of cataract surgery. Innovative IOLs, designed on the basis of cutting-edge technologies, are being developed or clinically tested to meet the increasingly ambitious goals of modern cataract surgery.
A first important advance has already been marked by the IOL for mini-incisionwhose small size has enabled the spread of mini- and micro-incision surgical techniques, the main advantages of which are the reduction of induced astigmatism and greater stability of the anterior chamber, with reduced complications from collapse (see Interview Dr. R. Bellucci).
Mention must therefore be made of the Preloaded IOLscertainly destined to become a standard in modern implantation techniques. The advantages are more than significant, both in terms of safety (in preventing the possibility of infection) and correct lens loading/release.
Other important progress was made with the Aspherical IOLswhich do not induce or partially correct ocular aberrations.
Indeed, the new aspheric IOLs make it possible to compensate for the positive spherical aberration of the cornea and reduce the risks of postoperative PCO (see article Prof. A. Caporossi).
In the current phase, one of the most ambitious targets is to simultaneously correct, in a single operation, not only cataracts, but also presbyopia.
Since presbyopia is a condition that arises physiologically with age, there is no doubt that eye surgeons will benefit greatly from the availability of new IOLs for this type of refractive cataract.
The most innovative products for the surgical treatment of presbyopia in recent years have been based on multifocality or accommodation actually achieved post-surgery.
The target of optimal 'artificial accommodation' undoubtedly constitutes the most important barrier to the rapid increase in market share of these high-tech products.
In recent years, the development of lenses for the surgical treatment of presbyopia has made much progress.
It started with the Refractive and diffractive multifocal IOLswhich, however, present a number of problems related to discontinuity of vision at different distances and, therefore, the formation of annoying post-operative halos.
As an alternative to multifocals, the Accommodative IOLswhich, however, have not been very popular with eye surgeons.
The latest are the IOL EDOFan acronym that stands for 'Extended Depth Of Focus' i.e. 'Extended Depth of Fire'.
As reported in the FDA report (Food and Drug Administration) the main advantages of EDOF IOLs can be summarised as follows:
- IOL design: designed to positively increase depth of focus and improve visual performance for near and intermediate vision without any negative impact on distance vision (continuous vision at all distances).
- Aberrometric correction on the optical surface.
- Advantages over multifocal optics:
- Less halos/glare
- Less loss of contrast sensitivity.
There is a lively debate going on among insiders about the final balance on the future development prospects of this type of lens.
One of the most promising examples of EDOF lenses based on spherical aberrations is the Mini WELL of SIFI Medtech, which made its market debut in March 2014.
It is an aspherical, pre-loaded, mini-incisional, progressive IOL with an extended depth of focus that provides a superior visual result compared to conventional diffractive IOLs.
The development of the Mini WELL optics is based on a patent owned by SIFI Medtech (US 8,529,559 and WO2009058755).
A clinical trial is currently underway, the results of which look very promising and about which we will keep our readers updated.
An opportunity to explore this topic was the satellite symposium 'Presbyopia: the beginning of a new era'held at the ESCRS congress in Barcelona on 7 September 2015.
Read thisarticle in English
For more details see:
– The new EDOF IOLs in the correction of presbyopia
– Biometrics and the success of refractive cataract surgery
– New horizons for presbyopia surgery
Dr. Carmelo Chines
Direttore responsabile