December 2019


Examining presbyopia treatments
Leaning in with the Light Adjustable Lens

by Vanessa Caceres EyeWorld Contributing Writer

The Light Adjustable Lens
Source (all): Stephen Slade, MD

How the Light Adjustable Lens works


The Light Adjustable Lens (LAL, RxSight) has been long awaited among cataract surgeons in the U.S., who witnessed their global colleagues using it before it became available in the States.
Approved by the FDA in late 2017 for patients with pre-existing astigmatism of 0.75 D or greater, initial users of the LAL are discovering best practices to maximize its potential. Here’s what some of these early practitioners have to share about how the lens works, its best candidates, and surgical pearls.

How the LAL works

For a patient receiving the LAL, cataract surgery is performed normally, and a standard three-piece silicone IOL is implanted. What’s different comes postoperatively.
“The ‘magic’ is in the optic,” Kevin Waltz, MD, said. “Seventy percent of the optic of the IOL is polymerized, and 30% is not. You can polymerize proportionately the IOL in place and change the optic.”
These polymers are activated by the Light Delivery Device to change the prescription, William Wiley, MD, explained. “This can be done 2 to 3 weeks after cataract surgery, ensuring you can achieve the patient’s visual target with a high degree of precision and accuracy,” he said.
Patients can have up to three adjustments performed with the LAL, John Doane, MD, said. Vision adjustments are done in 0.25 D increments after the corneal wound has healed.
Once the patient is satisfied with his or her vision, the surgeon “locks in” the vision using the Light Delivery Device. “In practice, the LAL is the most patient-customizable lens option to date and becomes analogous to a finely tailored dress or shirt,” Dr. Doane said.
Dr. Doane went on to explain how the light-based technology works. “The photosensitive silicone has free macromers within the lens substrate that can migrate depending on where the light is applied over the lens,” he said. “If it’s central light, then the central part of the lens will steepen and resolve a hyperopic refractive error. If it’s peripheral light application, then peripheral thickening and central flattening with a resultant reduction in myopic refraction will occur. For astigmatism, more light is provided along one major meridian than another, creating a singular spherical focal point impinging on the central retina.”
Patients receiving the LAL had uncorrected 20/20 vision or better at 6 months post-surgery at about twice the rate of patients receiving a standard IOL, according to the RxSight website.

Best candidates for the LAL

There are a few types of candidates who are best suited for the LAL.
First, a patient must be willing to have the series of light adjustments that will help tailor their vision, Dr. Wiley said.
Second, you’ll want a patient who doesn’t mind wearing glasses temporarily while their vision is fine-tuned. “Our patients really don’t seem to mind the glasses [temporarily]. This is Texas, and we’ve had several patients decorate their glasses with rhinestones,” said Stephen Slade, MD.
Patients who are concerned about their quality of vision may favor the LAL, as it doesn’t have the same problems with glare, haloes, or dysphotopsias as some of the other premium IOL technology. “The lens has increased our premium lens usage since the negative and positive dysphotopsia issues are equal to a monofocal lens, which is virtually zero complaints,” Dr. Doane said.
Another good candidate is someone who is a good personality match for the surgeon, because the surgeon and patient will work together closely to help achieve those visual goals, Dr. Wiley said. This can be tricky because there may be demanding patients who are not good multifocal IOL candidates but who can receive the LAL. Both parties have to be prepared to work together cooperatively.
Patients also have to be ready to pay for this premium technology.
Overall, patients appear to be pleased with results from the LAL, said the surgeons interviewed by EyeWorld, all of whom were part of the trials done before the LAL was approved.
One advantage that both patients and surgeons like is being able to try out monovision before it is locked in—in fact, patients who like monovision often are a good match for the LAL, Dr. Slade said. This is in contrast to patients in the past who received monovision with their IOLs and were unhappy with their vision. Surgeons were always left to wonder if the patient was unhappy with their actual vision or with monovision itself.
Another good group of patients for the LAL are those with previous refractive surgery—in fact, there is a trial now for this patient group, according to RxSight. “Someone with previous LASIK has already said with their pocketbook that they find their vision important,” Dr. Waltz said.

Poor candidates for the LAL

There are a few medical reasons why someone may not be a candidate for the LAL.
For instance, a patient who has a small pupil that does not dilate well is not a good LAL candidate. “The pupil has to be larger than 6 mm to achieve the light adjustments,” Dr. Wiley said.
If a patient has astigmatism that is greater than 3 D, the lens may not be ideal, Dr. Wiley added.
Another limitation is if a patient takes photosensitizing medications; this could include patients on various types of diuretics, Dr. Slade said. However, patients can still use the lens if they can discontinue photosensitizing medications during the light adjustment process, Dr. Doane said.

LAL pearls

With all the excitement over the LAL, it could be easy to dive in without much thought. However, surgeons share a few pearls to help potential users better plan for their LAL experience.

1. Do a site visit. Just as you would with many other types of new surgical technology, plan a site visit with someone already using the lens, Dr. Waltz advised. The cataract surgery itself is the same, but surgeons and staff will want to see the light adjustments and patient education as well as review scheduling nuances.

2. Consider scheduling. A key consideration with the LAL is the light adjustments that are done, Dr. Waltz said. For each cataract patient you treat who will get an LAL, there’s the potential for up to three separate light adjustments per patient. “That’s a lot of time and effort, and it’s a lot of coordination with you, your office, and patients,” Dr. Waltz said. To help manage this, have key staff come along during a site visit to see how experienced offices schedule those light adjustments. Also, consider offering more than one day or afternoon a week for those light adjustments, to help meet patients’ busy schedules. It may be helpful to have a partner who also offers the LAL to help broaden the adjustment schedule.

3. Plan the light adjustments around your peak concentration time. “Using the light delivery process is not hard, but it takes an incredible concentration,” Dr. Waltz said. “It’s a minute or two of holding something exactly center with an eye that is moving, and that takes some real concentration. If you do 10 in one afternoon, that’s 20 minutes of intense concentration. You can do it, but it’s a unique skill.” Plan with your staff when to best schedule light adjustments to take advantage of your peak concentration.

4. Make sure to follow the recommended protocols from the FDA trials regarding the light adjustments. You want to perform the light adjustments on an eye that has a stable refractive state to assure you are not treating a moving target.

At a glance

• The LAL gives patients customized vision after cataract surgery, made possible by a series of light adjustments postop.
• Good candidates for the LAL are patients who will return for light adjustments, can afford the technology, and do not mind wearing glasses for a couple of weeks.
• Poor candidates for the LAL are patients with small pupils, those who have a large degree of astigmatism, or who are using photosensitizing drugs.
• Set up a site visit with a seasoned physician using the LAL to get a better sense of how light adjustments work and how to schedule patients post-surgery for those adjustments.

About the doctors

John Doane, MD

Discover Vision Center
Kansas City, Missouri

Stephen Slade, MD
Slade & Baker Vision Center

Kevin Waltz, OD, MD
Partner, Whitson Vision

William Wiley, MD
Cleveland Eye Clinic

Relevant financial interests

Doane: RxSight
Slade: RxSight
Waltz: RxSight
Wiley: RxSight

Contact information


Leaning in with the Light Adjustable Lens Leaning in with the Light Adjustable Lens
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