Novel intraocular ring enhances IOL stability, prevents PCO
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A novel intraocular ring provides good centration and stable holding of IOLs in the capsular bag, while effectively preventing posterior capsule opacification.
“It also provides a stable environment for any future IOL replacement,” Ioannis Pallikaris, MD, PhD, said in an interview with Healio/OSN.
Posterior capsule opacification (PCO), he said, is a long-standing complication, and many attempts have been made over the years to prevent it. The square-edge IOL design is an important element in blocking epithelial cell migration to the back of the capsule and has significantly reduced the incidence of PCO.
“But still, it is not 100%,” Pallikaris said. “Study data in this respect are inconsistent, and personally I believe that moderate to severe PCO still occurs in around 10% to 20% of the cases.”
He said that even a small amount of PCO significantly affects the performance of advanced-technology IOLs because these lenses need to be centered on the visual axis. They are not forgiving of tilt and decentration, and just a small amount of capsular fibrosis that may not even lead to opacification affects the centration of the lens.
“This has been highlighted in all recent meetings, particularly speaking about EDOF lenses or about the modern multifocals. They need a very safe, stable, predictable and clear environment, and the capsule is not the best place in this respect. Even the slightest fibrosis changes the space and shape of the capsule, and the IOL goes out of place,” Pallikaris said.
A simple solution to many problems
The fixOflex ring (Eye PCR) was designed to solve this problem.
“It is the high-end result of a series of attempts I made, aimed at reconstructing within the lens capsule an environment that is similar to the natural form, and it functions in a similar way,” Pallikaris said.
The ring is made of hydrophilic acrylic material and is designed with fixed and flexible parts to adjust to the shape and size of the lens capsule. The flexible structures of the outer rim adhere to the Wieger’s ligament area, preventing cell migration and PCO while the IOL optic is held within the 6-mm central opening.
“The ring refills the capsule, occupying the space previously filled by the natural lens. As a consequence, it prevents the vitreous body from floating as it does after standard cataract surgery due to the absence of volume. Likely, this preserves the eye from developing posterior vitreous detachment,” Pallikaris said.
In addition, by blocking the edge of the IOL optic, the ring contributes to the elimination of night dysphotopsia, “a huge advantage,” according to Pallikaris.
Last but not least, the lens inside the ring is easy to manipulate in case it needs to be exchanged or repositioned.
“This is particularly important with toric IOLs. The ring enhances rotational stability, but if rotation occurs, it is easy to reposition the lens,” he said.
Repositioning or removing and replacing the lens will be possible at any time, even after years. This is another problem solved and a significant advantage in pediatric ophthalmology.
“We are planning studies at the pediatric hospital in Athens. PCO is very aggressive in children, and this ring may prevent it. Moreover, as the years go by and refraction changes, the lens can be easily replaced,” Pallikaris said.
Current and future studies
At the European Society of Cataract and Refractive Surgeons meeting, Pallikaris presented the results of an ongoing prospective study of 120 patients undergoing cataract surgery with fixOflex and IOL implantation.
“With 1 year of follow-up, we can already say that the lens is stable and safe with no significant side effects. Endothelial cell loss was within the normal limits of standard phacoemulsification surgery. No anterior chamber reaction and postoperative IOP changes were observed. No serious adverse events were reported, and no PCO formation was observed to date,” Pallikaris said.
The fixOflex ring can be used with any C-loop IOL. It is implanted through a 2.4-mm incision and adds about 1.5 minutes to the procedure.
“The mean time needed to insert and manipulate the ring in the study was 1 minute 17 seconds, a very little delay to our routine surgical time,” Pallikaris said.
Anterior segment OCT is providing useful information on how the ring sits in the capsule and how the IOL fits in the ring, as well as an overview of how the anatomy of the eye responds to the procedure, including the iris, the angle and the anterior chamber.
“We have studies undergoing in Egypt, Japan and Greece, we are identifying new parameters and collecting data for publications, and most importantly, we see that the surgeons who have tried the ring are very excited,” Pallikaris said.
An application for a CE mark has been submitted, while additional options to further improve the performance of the ring are being studied.
“We are also developing a version of the ring that allows to implant the lens eccentrically for eyes with a big angle kappa,” Pallikaris said. “We are also looking into the possibility of incorporating anti-growth factors in the material, so that the ring can be used also as a drug-eluting device to combat PCO in the first couple of days after IOL implantation.”
For more information:
Ioannis Pallikaris, MD, PhD, can be reached at Vardinoyiannion Eye Institute of Crete, School of Medicine, University of Crete, Heraklion, Crete, Greece; email: pallikar@gmail.com.
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