ESCRS Talks Technology at AAO

Four ESCRS leaders presented the latest in European eye surgery technology at Refractive Surgery Subspecialty Day during the American Academy of Ophthalmology annual meeting in Chicago, US.

Innovations

H Burkhard Dick MD, PhD led off featuring three breakthroughs that are not available in the US, despite greater funding and marketing opportunities and a more relaxed regulatory regimen.

“In Europe, MDR is like walking a tightrope over a river full of crocodiles while juggling with checklists,” he said. “The FDA looks like a moonwalk through the approval process, but I know you have to spend $32 million if you want to bring an IOL to the market.”

Laser-induced refractive index change (LIRIC) uses a femtosecond laser to break the bonds of monomers in hydrogel lenses to change their refractive power. LIRIC is being developed by Schwind and University Eye Clinic in Bochum, Germany, for use in corneal tissues to treat refractive errors. In animal trials it is proving feasible, effective, and safe, and human trials could begin in 2026, Professor Dick said.

A handheld, battery-powered femtosecond laser for cutting perfectly centred anterior capsulotomies is now available in Europe from Helix Surgical. It requires no suction, takes 4 seconds, and integrates well into patient workflow, Prof Dick said. “The results are very consistent.”

A small-aperture mask from Morcher that can be placed in the capsular bag or sulcus on top of any intraocular lens (IOL) is succeeding in clinical tests. Implantable through a 2.0-mm incision, the removable device can be used with any lens to add depth of focus, making it more flexible than a dedicated small-aperture IOL.

“The future is undeniably bright, with more breakthrough moments and Europe’s ongoing role in co-shaping the future,” Prof Dick concluded.

Choosing an IOL

A huge array of IOLs is now available in Europe, and choosing among them requires careful evaluation of their characteristics, said Filomena Ribeiro MD, PhD.

Materials—whether hydrophobic or hydrophilic acrylic—influence everything from posterior capsule opacification to flexibility, centration, and quality of vision, Prof Ribeiro noted. Recently, improvements have been made in hydrophobic acrylic lens materials to address issues, including spherical aberrations and glistenings, she added.

Platforms also vary widely, with lens stability influenced by factors such as haptic design and lens diameter versus capsular bag size. These influence decentration, rotation, tilt, and axial displacement, all of which affect vision outcomes. Designs range from the classic C-loop to open C-loops to four-haptic and plate designs. Some are available in multiple sizes to fit the capsular bag.

And then there is optical design. IOLs can be classified as refractive, diffractive, or small aperture, but also by number of focal points, extended depth of focus (EDOF), or enhanced monofocal, Prof Ribeiro said. Trifocals are evolving toward fewer light-splitting rings and providing more light to intermediate vision, with some even incorporating refractive qualities or entirely refractive designs.

Generally, EDOF lenses provide less spectacle independence but better quality of vision and higher contrast sensitivity, Prof Ribeiro said. But as new lenses develop, distinctions among them blur, and the design alone tells little about how they function in patients’ eyes. ESCRS has compiled a functional classification system to help guide lens choices.

“Sometimes it’s not easy because we have diffractive IOLs that are considered EDOF, EDOF that perform like a bifocal, etc., so everything is right now very complex,” she said. “We have a very large catalogue of IOLs.”

Improving refractive outcomes

In the 75 years since the IOL was invented, refractive outcomes for cataract and now refractive lens exchange have steadily improved. That’s thanks in large part to improved technology and lens power calculation formulas that have addressed the main sources of error, said Oliver Findl MD. Current and near-future innovations hold promise for further improvement.

The 1990s saw the start of optical biometry used to help minimise the impact of axial length measurement errors on refractive error. Swept-source optical coherence tomography (OCT) further improved accuracy, allowing measurement of axial length, corneal thickness, anterior chamber depth, and lens thickness, enabling more accurate prediction of postoperative effective lens position.

But OCT remains expensive. Using surface-emitting laser diodes similar to those in laser printers and mobile phones soon could reduce OCT cost by as much as 100-fold, making it more available in limited resource settings, Prof Findl noted. “Cheaper technology is on the horizon.”

Accurate keratometry is also critical, Prof Findl said. Dry eye is particularly problematic, but treating it for weeks before surgery is cumbersome, unreliable, and may not improve keratometry accuracy much. Having patients close their eyes for 5 minutes before scanning can significantly improve surface hydration and scan quality. He added scans should be assessed for mire distortion before proceeding.

Accurate postoperative refractions also remain a significant source of error, and more robust measurement is needed. “Unaided 20/20 is not enough,” Prof Findl said, noting measurements down to 0.25 D and better reproducibility would improve outcomes.

Last, he said accurate IOL power calculation is critical to estimating effective lens position. The ESCRS online calculator enables users access to several formulas with data entered just once. Variations in predictions can help identify potential refractive surprises in advance, allowing for patient counselling and effective treatment planning.

Phakic IOLs

Rapid increases in myopia and high myopia over the next 25 years will drive greater interest in phakic IOLs (PIOL), said Thomas Kohnen MD, PhD. Available in Europe since the mid-1980s, various angle-supported and iris-fixated anterior chamber PIOLs have evolved.

However, angle-supported lenses were pulled from the market due to problems with pupil ovalisation and long-term endothelial cell loss. Iris-claw lenses are also associated with long-term endothelial cell loss, especially in patients with shallow anterior chambers, so these must be monitored over the long term, Prof Kohnen noted.

Ciliary sulcus-fixated PIOLs, such as the posterior chamber implantable collamer lens (ICL, Staar Surgical), are also associated with mild endothelial cell loss. Recent models with a central hole have nearly eliminated cataract formation, making them attractive for high myopia correction, Prof Kohnen said.

An aspheric presbyopia-correcting ICL is now available, providing 0.1 logMAR visual acuity across roughly 2.00 D. “It is a good alternative for high myopia patients from age 45 to 55 years,” Prof Kohnen said. Another available option is a multizone refractive iris-fixated presbyopia-correcting PIOL that offers a full range of vision (Artiplus, Ophtec).

Current German guidelines, updated in 2022, call for PIOL use for myopia of -1.00 D or more and presbyopia of +1.00 or more. Astigmatism may be treated with a toric IOL or laser surgery, Prof Kohnen said. Upcoming ESCRS refractive surgery PIOL guidelines will be similar but add minimum anterior chamber depths of 2.8 mm for myopia and 3.0 mm for hyperopia, with astigmatism correction for 1.00 D or more.

In conclusion, Prof Kohnen noted that anterior chamber angle-supported lenses are no longer sold, though iris-fixated lenses are available in both Europe and the US. But “the winner at the moment seems to be ciliary sulcus-fixated lenses, going back to Fyodorov in 1993, also in presbyopia correction.”

H Burkhard Dick MD, PhD, FEBOS-CR is professor and chairman of the Ruhr University Eye Hospital in Bochum, Germany, and ESCRS president elect. dickburkhard@aol.com

Filomena Ribeiro MD, PhD, FEBO is head of ophthalmology at Hospital da Luz, Lisbon, Portugal, associate editor of the Journal of Cataract and Refractive Surgery, and ESCRS president. filomenajribeiro@gmail.com

Oliver Findl MD, MBA, FEBO is professor and chair of ophthalmology at Hanusch Hospital in Vienna, Austria, and past president of the ESCRS. oliver@findl.at

Thomas Kohnen MD, PhD, FEBO is professor and chair, Department of Ophthalmology, Goethe University, Frankfurt, Germany, and past treasurer of the ESCRS. kohnen@em.uni-frankfurt.de