Cataract surgery is one of the most common surgical procedures performed in the United States.1 In a world of advancing technology and longer life expectancy,2 modern cataract surgery is no longer limited to vision restoration but instead may have a marked impact on maintaining and improving vision-related quality of life.3 Patients now expect high-quality vision that matches their dynamic lifestyles and unique needs.3 As a result, the intraocular lens (IOL) market has seen an emergence in lens replacement options attempting to meet the increasing demands and expectations of patients undergoing cataract surgery.4
Historically, traditional cataract surgery has relied upon the use of fixed-power IOLs. However, it is estimated that only 70-75% of cataract surgeries utilizing fixed-power IOLs achieve their post-refractive target,5 which can create gaps in patient expectations regarding their visual goals. Additionally, achieving predicted post-op targets does not necessarily guarantee patient satisfaction. The development of the Light Adjustable Lens™ (LAL®/LAL+™) has begun to disrupt the classic treatment paradigm by allowing the power of the IOL to be titrated approximately two to four weeks after surgery. Not only does this permit modifications to the IOL that may not have been accounted for during preoperative testing but the IOL can also be customized for each patient’s lifestyle and unique visual needs in real time, post surgically.
Created by RxSight, the Light Adjustable Lens is the first and only (at the time of publication of this article) FDA-approved IOL whose refractive power can be adjusted postsurgically – giving both doctors and patients more control in visual optimization.
What are the limitations of traditional “fixed” intraocular lenses?
A successful IOL implantation that can achieve the intended refractive result in the eyes of both surgeon and the patient relies in part on careful preoperative planning. This workflow might be impacted by confounding factors that can be difficult to control, including common sources of error when performing biometry like IOL position, axial length, and corneal power, in which small discrepancies can have a major impact on final results.6 The presence of higher order aberrations, the patient's astigmatic profile, and the status of the ocular surface and tear film can also play a major role in postoperative outcomes,7,8 adding another layer of complexity to postsurgical visual outcomes, including the corneal healing process and postoperative lens positioning. These factors can ultimately lead to refractive surprise postoperatively, which may warrant the need for additional procedures such as refractive corneal surgery (i.e. LASIK or LRI), or less favorable, an IOL exchange.
What makes the RxSight Light Adjustable Lens different?
RxSight has changed the game in the cataract surgery arena with the Light Adjustable Lens.9 As a result of proprietary photosensitive material that can be reshaped in response to ultraviolet (UV) light, the Light Adjustable Lens can be adjusted postoperatively up to three times in approximately two to four weeks to improve uncorrected visual acuity. Not only does this allow for lens power modifications that may provide a solution in cases of refractive surprise, but it may also help to reduce the impact of variability in the preoperative decision-making process. The adjustability of this lens allows for patients to test drive their postoperative visual outcome in their daily lives and provide feedback to the surgeon and co-managing doctors for modification prior to finalizing postsurgical vision. Subsequently, this empowers the patient to be more vested with a level of control in their visual outcome.
How exactly does the Light Adjustable Lens work?
The Light Adjustable Lens is a silicone, three-piece IOL (two haptics to hold the lens in place) that contains photosensitive macromers distributed throughout the lens. When a wavelength of 365 nm of ultraviolet (UV) light is applied from an instrument called the Light Delivery Device (LDD) directly to a specific area of the lens, the macromers in the path of the light polymerize to neighboring macromers. The remaining unpolymerized macromers then diffuse into the light-exposed area. This movement can create a highly predictable change in the curvature of the lens that effectively revises the spherical and sphero-cylindrical power of the lens.
It should be noted that the LDD delivers light treatment as opposed to laser treatment. While the LDD delivers light of a single wavelength as would a laser, this light treatment delivers incoherent light while a laser delivers coherent light.
The Light Adjustable Lens is available in powers of +4 D to +30 D, with availability from +16 D to+24 D in 0.50 D increments to match the patient’s refractive target as closely as possible. From there, the LDD can manage up to 2 diopters of myopic or hyperopic spherical refractive error and up to 2 diopters of astigmatism.
Residual astigmatism (> 0.75 D) is one of the most common sources of patient dissatisfaction postoperatively.10 Of note, the Light Adjustable Lens can correct as low as 0.50 diopters of astigmatism. The ability to treat 0.50 diopters of postoperative cylinder makes this IOL the only technology in the United States approved to correct this level of astigmatism.11 From a clinical perspective, leveraging this capability could enhance postoperative visual satisfaction along with dynamic, functional visual acuity and low-contrast acuity.11
Who is a candidate for Light Adjustable Lens?
Nick Bruns, OD, FAAO, has been practicing in the refractive surgery space for his entire career, has experienced his patients receiving enhanced visual outcomes with a Light Adjustable Lens. He would pose the question, “Who isn’t a good candidate for an RxSight Light Adjustable Lens?” Dr. Bruns has found that the overall proportion of patients in his practice could benefit from Light Adjustable Lens—far outnumbering those who might not be appropriate candidates for the lens.
Ron Carr, OD, FAAO, an optometrist with over 30 years of practice in a co-management setting, has also observed tremendous patient satisfaction when electing to proceed with a Light Adjustable Lens. He finds it meets the visual needs of many of his patients through its adjustability in the weeks following cataract surgery. Dr. Carr believes that the capability to customize the lens power postoperatively makes it a viable treatment option for a wide array of patient types. He also emphasizes the importance of patient education and setting realistic expectations—especially when it pertains to a patient’s preoperative visual demands and lifestyle goals.
A look at the Light Adjustable Lens workflow—the journey and considerations
As with any cataract surgery, the preoperative workflow begins with patient education and setting appropriate expectations. A simplified scripted explanation for patients about the Light Adjustable Lens process during the initial cataract evaluation is an imperative step to set them up for potential success. While the patient ultimately has decision-making authority, they still need to explicitly understand both the time commitment and the critical importance of strict adherence to the protocol from the Day 1 postoperative visit to the final lock-in treatment.
It is important to stress compliance with UV-protective lens wear early and often throughout the entire surgical journey, as non-compliance may affect a patient’s refractive outcomes if the macromers of the lens are altered by other ultraviolet light sources, such as the sun. The Light Adjustable Lens does incorporate redundant UV protection within the anterior portion of the lens called ActivShieldTM that provides an extra layer of protection against UV light. Subsequently, this feature of the Light Adjustable Lens aids to lessen the potential concern for accidental sunlight exposure in the patient’s everyday environment.12
It is imperative that patients comply with required follow-up visits. The Light Adjustable Lens process consists of both LDD adjustment and lock-in treatments. Of note, the patient will undergo at least one adjustment treatment at 2-3 weeks and can have up to 3 per eye, with 2 lock-in treatments per eye to reach an appropriate visual endpoint based on the patient’s goals and lifestyle.
It is critical to communicate these steps to patients throughout the cataract surgery journey as they may have pre-existing expectations regarding the postoperative follow-up schedule from friends or family members who elected to pursue standard cataract surgery. As an added benefit, these visits provide additional touchpoints with patients to champion their selection of the Light Adjustable Lens while reminding them of their lifestyle and overarching visual goals. In totality, this serves to strengthen rapport with patients.
“I’ve been pleasantly surprised with how patients actually look forward to the chair time between surgery and our final light treatment,” says Dr. Bruns. “The time between each light adjustment gives the patient a really exciting opportunity to live their life, see where we’ve met the mark, and then take ownership over their own improvements. Overwhelmingly, our patients enjoy the adjustment period and it’s not at all a deterrent.”
Dr. Bruns also adds that the period of intimately working with patients enables him to strengthen the doctor-patient relationship, a critical element for successful incorporation of unique technology and practice growth.
Taking a closer look: Light Adjustable Lens implantation to adjustment
The surgical implantation of the Light Adjustable Lens following cataract extraction follows the standard procedures of most three-piece IOLs, although a specific and proprietary IOL insertion device is used during surgery for the RxSight Light Adjustable Lens.
Each office’s exact postoperative schedule may vary, though the postoperative drop schedule is similar to standard or other premium cataract surgeries. A one-day postoperative visit is common, and a one-week visit can be performed by the comanaging eyecare provider (ECP). At the first postoperative visit at which an adjustment could potentially be performed, a technician or ECP would ask guided intake questions, obtain another objective refractive measurement, and take the patient’s visual acuity at all ranges.
Afterward, refraction would be performed coupled with a supportive discussion with the patient about their visual goals and to reiterate realistic expectations. The next step would be to demonstrate any potential adjustment options with trial lenses, along with patient input to assist with the ECP’s decision-making for the LDD treatment. This is a great moment to model what the patient’s vision might look like ahead of the lock-in visits.
The doctor will then perform a slit lamp exam to assess the level of anterior chamber inflammation present and whether ocular surface dryness might warrant waiting until a subsequent visit to perform a light adjustment. If the ECP has determined the healing process to be stable and that a LDD adjustment can be performed, the patient would be dilated to fully visualize the Light Adjustable Lens haptics and optic.
The first light adjustment of the IOL, however, is not performed until at least 17 days have passed to allow enough time for proper healing, in accordance with original FDA studies13. Subsequently at the 17–21-day mark after surgery, patients can return for examination and their first adjustment treatment. The second and third adjustment treatments, if necessary, are all separated by about 3-5 days.
Patients generally receive their first lock-in treatment at 3-5 days after the final adjustment treatment. The second lock-in treatment may be performed 3-5 days thereafter. Depending on the adjustment(s) performed, all eyes can receive one to three adjustments and one or two lock-in treatments.
Note: The additional postoperative commitment required for patients choosing the Light Adjustable Lens can impact the surgeon’s typical scheduling patterns.12
Dr. Bruns chooses to take the adjustment period one step at a time:
“We do the first treatment after day 17 if the patient is healed,” he says. “I use the analogy of a golf course, where you start with the ball on the fringe and aim for that first hole. We may get lucky and hit it right away, but it’s ok if we need to let that ball come to rest and realign because we know we are going to get there.”
Light Adjustable Lens workflow snapshot:
Dr. Bruns supports the idea of letting a patient “live” in a lens, whether this means postponing an adjustment for a vacation or just to go play golf and learn more about what they would like to improve.
“The post-op period is really exciting,” adds Dr. Carr. “Patients are seeing improvements in their vision and it’s all leading up to the lock-in.”
The lock-in process is initiated after three adjustments have been performed, or sometimes after only one or two if the patient is pleased with their vision. The process consists of two separate visits, though a final refraction is required at the first lock-in visit, prior to dilation. A lock-in treatment is similar to an adjustment, except that the refractive power is not changed, and the light is delivered over the entire lens. During the lock-in, the molecules in the IOL become “frozen,” and are no longer able to be adjusted.
The lock-in light is delivered for 90 seconds during the first lock-in treatment, and 120 seconds for the second lock-in treatment. The patient should be made aware that their eyes may feel more dry than usual following the lock-in treatment, which is why Dr. Bruns recommends the use of lubricating drops during this time.
The patient should continue to wear their UV protective lenses until 24 hours after their second and final lock-in treatment.
Does the UV light administered during LDD treatments pose any safety issues?
The high safety profile for both the Light Adjustable Lens and the LDD has been extensively documented through long-term results of multiple studies.14 A trial evaluating the potential negative effects of UV irradiation exposed to the macula found that the UV light administered to the Light Adjustable Lens during the LDD adjustment treatments did not affect the development of postoperative cystoid macular edema (CME) and had no effect on the layers of the macula.15 Additionally, there were no signs evident of retinal toxicity after a study was conducted to evaluate this type of potential tissue damage using up to 5 times the maximum dosage of UV light used during LDD treatments.16 Further, it was found that the UV light exposure for LDD treatments did not add to corneal endothelial cell loss caused by cataract surgery itself.15, 17
Why choose adjustability?
The ability to customize the Light Adjustable Lens after cataract surgery gives the patient the opportunity to influence their postoperative vision. When asked his thoughts on the Light Adjustable Lens compared to other premium IOLs, Dr. Carr shared that “there has not been in my experience a better quality of vision postoperatively.” Additionally, Dr. Bruns added that “there's always a “but” with a multifocal lens or an EDOF lens. Rarely do we get anybody who's unhappy as long as we've set the expectation to be realistic, too.”
Postoperative considerations: Impact of dry eye disease on the Light Adjustable Lens process?
Similarly to how dry eye disease (DED) can significantly impact preoperative biometry measurements for cataract surgery, it can also impact the accuracy of the postoperative refractions and delay the Light Adjustable Lens postoperative treatment timeline.
It is known that intraocular surgery can induce the symptoms of DED19 and it is considered an underestimated problem for patients undergoing cataract surgery.1 A reduction in tear film quality can directly impact vision quality after cataract surgery and create delays in assessing refractive targets during the postoperative period. With this said, it is highly recommended to take a proactive approach to identify DED and initiate ocular surface treatment for patients at the preoperative planning stage prior to cataract surgery in order to optimize biometric results. This includes assessing for blepharitis, meibomian gland dysfunction and neurotrophic keratitis (NK), since all of these conditions can be instigators and/or comorbidities of DED. In the off chance that symptoms only arise in the postoperative period, it would be advised to follow a similar treatment protocol noted preoperatively to decrease the inflammatory response.
Referring the patient back to their optometrist for ocular surface management between Light Adjustable Lens treatments is a refined approach and a great way to illustrate the collaborative OD/MD relationship. It’s mutually beneficial—as the Light Adjustable Lens patient can be confident that they are under the care of an ophthalmic team who has the pulse on their visual needs from start to finish.
The optometrist’s role with the Light Adjustable Lens
The chair time and attention needed for each Light Adjustable Lens patient often requires a collaborative approach between the co-managing optometrist and surgeon to provide a seamless patient cataract surgery journey and enhanced experience. An accurate refraction at each postoperative visit is crucial, and optometrists are not only well versed to provide these, but oftentimes have access to refractive data and historical knowledge of the patient’s lifestyle which may help shape the discussion surrounding how best to map out the adjustment visits and respective visual expectations.
Dr. Carr believes that too often, optometrists think they don’t need to be involved with cataract IOL technologies, since surgeons have traditionally been the decision-makers. “I would really encourage optometrists who are new to this technology to become thoroughly educated by attending meetings, reading articles, meeting with the surgeons, and understanding the process that's involved,” he explains. “The surgeon often relies heavily on the refraction that's provided to them by the optometrist. So, I think this is absolutely an arena in which optometrists can and should be involved.”
As Dr. Bruns says, “if you're not offering this to your patients you're going to lose patients — because they’re going to go to another practice that offers it. We may have patients coming to see us who found us on the internet. If that happens to be your patient and you're not co-managing these types of patients, that will potentially affect your practice. So, my advice to optometrists is to really get involved and know the technology. We're critical players with this technology and we should be well educated about it.”
What’s new for RxSight and the Light Adjustable IOL?
There are over 732 practices with 1,300+ surgeons and 400+ optometrists who have embraced the Light Adjustable IOL in their practices.
In early 2024, RxSight introduced the LAL+ which has been optically designed to slightly extend the depth of focus of the lens compared to their previous model. They have also updated the form factor of the LDD, coming in a more compact size to better serve surgeons with limited office space.
“This technology is here to stay, and if you're not getting in now, you're going to be behind," says Dr. Bruns. "So if you consider yourself somebody who is technologically driven and on the forefront of eye care, this is it."
Final takeaways
The Light Adjustable Lens is the first and only intraocular lens that can be customized after cataract surgery, uniquely giving the surgeon, the optometrist, and the patient a shared partnership in defining and enhancing the visual outcome.
By embracing your role in Light Adjustable Lens adoption, you might begin to think differently about the cataract surgery discussion. By shifting the narrative towards a customizable visual experience, it can empower patients to be more vested in the process, along with appreciating the ECP’s skill set to help meet the moment to match their lifestyles goals to the final outcome.
Acknowledgments This article was peer-reviewed by Michael S. Cooper, OD, President, Visionary Medical Education, LLC.
