Adjustable IOL helpful in correcting residual errors after surgery

The lens provides better predictability, accuracy and amplitude of accommodation, a surgeon said.

PARIS — An adjustable IOL used by a small number of surgeons in France will soon be more widely adopted, according to a speaker at the meeting of the French Society of Ophthalmology.

The Light Adjustable Lens (Calhoun Vision) is made of a flexible polymer matrix with mobile, photosensitive silicone subunits. Once implanted, the lens is irradiated with a cool beam of near-UV light for power adjustment.

“In terms of accuracy, predictability, cylinder correction and amplitude of accommodation, it is like no other lens,” Michael Assouline, MD, said.

Correcting residual error

Dr. Assouline began using this technology after reviewing 4,434 cataract procedures and realizing that residual refractive error was greater than expected.

“We aim at achieving emmetropia, correction of the astigmatism with toric lenses, compensation of presbyopia with multifocal lenses, a high quality of vision, prevention of complications and, patient satisfaction,” he said. “The scatter plot of my cataract surgery in the last decade clearly showed how much we have improved, thanks to the latest refinements in the procedure and IOL technology. However, there was still some dispersion in terms of spherical equivalent and cylinder.”

So far, Dr. Assouline has been using the Light Adjustable Lens (LAL) for limited indications, mostly in eyes with residual refractive error after refractive surgery, corneal transplantation, corneal scar, keratoconus and high hyperopia.

“I have only used it in 10 cases, but results were remarkable. In one case, refraction improved from preoperative +4 D to postoperative –0.58 D and visual acuity from 20/50 to 20/25. In another patient with poor outcomes from a previous presby-LASIK procedure, visual acuity after LAL implantation was 20/16. She maintained corneal multifocality and was able to read J1,” Dr. Assouline said.

The overall LAL results were better than those of other implants, standard or multifocal, and excimer laser procedures, he said.

Predictability was also superior, and a more accurate correction of sphere and cylinder as well as a higher than average amplitude of accommodation were obtained.

“This implant allows modulation of spherical aberration. By stretching out the depth of focus with increased spherical aberration, a correction of presbyopia comparable to the results of multifocal implants can be achieved,” he said.

Advantages, drawbacks

The three-piece silicone design of this lens requires a 3.2-mm incision, offering benefits in terms of vision alongside the drawbacks of a large incision.

Also, this kind of implant requires motivation and cooperation from the patient.

“Patients must come back for the locking-in procedure and are seen more often than average. In addition, they must wear protective glasses for 1 month,” he said.

While only one eye is operated, patients who need spectacle correction in the contralateral eye can utilize fit-over protective eyewear from Calhoun Vision. – by Michela Cimberle

• Michael Assouline, MD, can be reached at Centre Iéna Vision, 37 rue Galilée, 75116 Paris, France; +33-1-45569292; fax: +33-1-45555500; e-mail: rdv.assouline@gmail.com.

Dr. Assouline points out a reality, which is that at least 60% of our cataract patients have a significant residual ametropia. With the LAL, this issue may be easily addressed.

However, the use of the LAL has a substantial impact on clinical practice, as it requires more office visits than a standard lens for the lock-in procedure and in the follow-up. Not a problem, however, if the patient is sufficiently motivated and your team is well-organized.

– José L. Güell, MD
OSN Europe Edition Board Member