With ability to provide LASIK-like outcomes, the light-adjustable lens creates a new opportunity for cataract surgeons to grow the premium channel, says Fritz H. Hengerer, MD, PhD.
Results from U.S. and European premarketing studies show that a light-adjustable lens (LAL; RxLAL, RxSight) can bring LASIK-like outcomes to cataract surgery, said Fritz H. Hengerer, MD, PhD, at the 2018 ASCRS Symposium.
He reported that compared with a standard monofocal IOL or a toric IOL, the LAL is associated with a greater than two-fold improvement in the percentage of patients achieving UCVA of 20/20 or better. The data also show that more than 90% of eyes implanted with the LAL achieve a refractive outcome that is within 0.5 D of target.
“Residual refractive error is still common after cataract surgery due to variations in postoperative lens position and wound healing, and so the ability to consistently achieve great results and meet patient expectations remains a challenge,” said Dr. Hengerer, senior head physician/deputy director, Department of Ophthalmology, Heidelberg University, Germany.
“With ability to provide LASIK-like outcomes, the LAL creates a new opportunity for cataract surgeons to grow the premium channel,” Dr. Hengerer said.
The LAL has received FDA approval and the CE mark, but has not been launched commercially. It is a foldable IOL that can go through a 2.8 mm incision. It has a 3-piece design and 6 mm optic made of a UV photosensitive silicone material. It is implanted using an injector system that goes through a 2.8 mm incision.
About 2 weeks after surgery, once healing is complete and refraction has stabilized, residual refractive error can be adjusted to target in an office-based procedure using the proprietary Light Delivery Device. The treatment takes about 90, seconds and the procedure is similar to performing an Nd:YAG capsulotomy, Dr. Hengerer said.
Both sphere and cylinder can be adjusted postoperatively, alone or in combination. In the US FDA study and in a prospective European study conducted at the Center for Vision Science, Ruhr University Eye Clinic, Bochum, Germany, the adjustment range was between -2 and +2 D for sphere and 0.75 to 2 D for cylinder.
Dr. Hengerer stated that an expanded range for cylinder adjustment, between 0.5 to 3.0 D, was subsequently approved in Europe.
Once the patient is satisfied with vision, the IOL power is permanently locked with another treatment.
The LAL U.S. FDA clinical study was conducted at 17 centers and included 391 eyes implanted with the LAL and 193 controls that received a monofocal IOL. The study conducted at Ruhr University included 122 eyes. In both studies, patients returned after 6 months to determine functional and refractive outcomes.
In the U.S. study, UCVA of 20/20 or better was achieved by 70% of LAL eyes and 36% of the monofocal IOL controls. In the German cohort, 88% of LAL-implanted eyes achieved UCVA of 20/20 or better. Dr. Hengerer noted that in the US FDA study of an acrylic toric IOL, only 38% of eyes achieved UCVA of 20/20.
Manifest refraction spherical equivalent (MRSE) was within 0.5 D of the intended correction in 98% of eyes in the German study and in 92% of eyes in the US study.
“These outcomes compare very favorably with the results of modern LASIK that show about 91% of cases are within 0.5 D of intended MRSE,” Dr. Hengerer said.
Dr. Hengerer said that the LAL can be considered for almost any cataract surgery patient. The only limitation is that the pupil must be at least 6 mm in order to perform the UV light treatment.
He suggested that because it delivers such extreme refractive precision, the LAL solves the shortcomings of monovision as a treatment for presbyopia.
“The usual target for monovision is 0.75 to 1.00 D of anisometropia, but currently, it is hard to hit the desired offset. The LAL can dramatically improve binocular accuracy, and it also gives patients the ability to test-drive monovision and see if they are happy,” Dr. Hengerer said.
He also said that the LAL is particularly attractive for use in cases where postoperative refractive predictability is more challenging.
“The LAL can be used in nearly all patients, but it is especially useful in people with a history of LASIK or other corneal refractive surgery,” Dr. Hengerer said. “These patients also have high expectations for excellent outcomes.”
In addition, to the expanded cylinder range, product improvements implemented since the LAL received the CE mark include a 10-fold reduction in retinal exposure during the adjustment treatments, introduction of a proprietary re-usable injector system for delivery through a sub 3-mm incision, and reduced need for postoperative visits.
Dr. Hengerer is a consultant for RxSight.