Light-Adjustable Lens Yields Positive Outcomes

Cheryl Guttman Krader reports from ASCRS in Las Vegas, USA

Real-world outcomes with the Light-Adjustable Lens (LAL, RxSight) in clinical practice appear to be as good if not better than those seen in the US FDA clinical trial that led to its approval, Joshua K Duncan DO reported.

Dr Duncan presented findings from a series of 600+ cases of LAL implantation. In addition, he discussed considerations for surgical planning and LAL removal, highlighted the benefit of the updated LAL featuring a new UV protective layer (ActivShield), and described a novel, interesting off-label case involving intrascleral fixation of the LAL using the Yamane technique.

“We are all aware of the current challenges faced with achieving the refractive target in cataract surgery. Preoperatively we rely on accurate biometry, topography, and OCT imaging. Intraoperatively we use tools such as the femtosecond laser, aberrometry, and alignment aids. Still, we fall short and often resort to additional surgery with LASIK enhancement or IOL exchange,” Dr Duncan said.

“In our practice, we have been very pleased with the refractive and visual outcomes using the LAL, and it has been a nice driver for our premium channel.”

Dr Duncan added the LAL still has limitations because it is a monofocal lens. However, surgeons can achieve excellent visual acuity for their patients at all distances when implanting the LAL with a monovision approach.

In a small study involving 25 patients, the functional results with LAL monovision rivaled those achieved with a trifocal IOL, while dysphotopsia and contrast sensitivity with the LAL were similar to results associated with a monofocal lens, Dr Duncan said.

PRACTICE OUTCOMES The 600+ cases from his practice series represented procedures performed by four surgeons. More than half of the eyes had a history of LASIK or radial keratotomy (RK). After LAL lock-in, residual spherical equivalent (SEQ) was ≤0.5 D in 97% of eyes and averaged 0.12 D in the total population and 0.15 D in the post-refractive surgery subgroup. Distance UCVA was 20/25 or better in 92% of all eyes and 91% of those with prior refractive surgery. UCVA of 20/20 or better was achieved by 74% of eyes, of which a significant proportion saw 20/15 or better.

“The LAL is my ‘go-to’ lens for anyone with a history of LASIK, PRK, or RK,” Dr Duncan said.

He added that his refractive targets for the dominant/nondominant eye are plano and -1.00 D for patients with a history of monovision and plano/-0.50 D for those without prior monovision.

“These targets are a starting place and are adjustable,” Dr Duncan said.

He reiterated an often-mentioned tip to miss on the hyperopic side in the nondominant eye to increase depth of focus/ spherical aberration.

“Initially, we aimed to miss the hyperopic side in both eyes, but patients were not happy with the hyperopia during the time they were waiting to achieve refractive stability. That is not helpful for building a refractive practice, and I think patients do not need so much depth of focus in their dominant eye.”

The new LAL that incorporates a UV protective layer in the anterior portion has been helpful for patient satisfaction. According to RxSight, the layer is meant to provide redundant UV blocking along with UV glasses before lock-in. Dr Duncan believes it eliminates the need for patients to wear UV glasses around the clock.

“I still ask patients to wear the glasses if they are outside during the day because Phoenix is very sunny. Before the new UV protective technology, however, being tied to UV glasses was a significant nuisance for patients. Now, it is easier to wait for better refractive stability, which in post-RK patients in particular can take some time.”

Dr Duncan estimated that in total, he and his practice colleagues removed the LAL because of refractive error in only six to eight eyes. The patients involved in these cases all received the original LAL and either experienced a late refractive shift, perhaps because the adjustment and lock-in were performed prior to achieving refractive stability, or were noncompliant with wearing the UV glasses before lock-in.

If removal is necessary, Dr Duncan said surgeons should be aware the LAL is somewhat brittle.

“Be sure to use a lot of viscoelastic. Also, we used special IOL cutters that are a little finer and gentler,” he advised.

The case where he used the LAL with the Yamane technique involved a referred patient who was left aphakic after undergoing complicated cataract surgery with tears of the anterior and posterior capsule, iris trauma, and vitreous loss.

“I felt the patient was a great candidate for the LAL because his fellow eye was 20/20 uncorrected, and he wound up with 20/15 vision in the LAL eye after lock-in,” Dr Duncan said.

Joshua K Duncan DO is in private practice in Phoenix, Arizona, USA. jduncan@horizonlaservision.com