Pacific Cataract and laser Institute

Precise Customized Vision with

Light Adjustable Lens

By Mark Maraman, OD  |  PCLI—Chehalis, wa

distributed quarterly to 2700 optometric physicians      Winter 2021

In traditional cataract surgery, the science and decision-making of selecting IOL powers can be challenging. Despite the best measurement devices and most predictive formulas, we cannot foretell exact outcomes. The inability to be fully confident in lens selection can be stressful for surgical providers and sometimes disappoints patients.

The revolutionary new Light Adjustable Lens (LAL) by RxSight changes that.

Adjustable After Surgery

The LAL’s shape and prescription are designed to be changed after cataract surgery. Being able to repeatedly adjust this lens allows us to work with patients to customize their vision. They can test-drive monovision and different visual outcomes to see what works best for them—before the final prescription is made permanent.

After the eye heals from surgery and vision is stable, our doctors optimize the LAL’s refractive power with a clinic-based UV light source. Several adjustments are performed over a number of weeks. Once the patient is happy with their vision, a final light treatment locks in the prescription.

Although the FDA approved the LAL in 2017, its commercial launch in the U.S. did not get underway until 2019. But implementation is taking off as more patients are benefiting from this revolutionary and precise technology.

How the LAL Works

At a glance, the LAL looks similar to many IOLs. It is a three-piece 13 mm foldable implant with a 6 mm optic and squared posterior edge.

A wide range of powers is available. However, while most IOLs in the U.S. are made of hydrophobic acrylic material, the LAL is made of photoreactive silicone. When exposed to UV light, it changes shape.

During light adjustment treatment, photosensitive silicone macromers in the path of light are photopolymerized. As a result, unpolymerized macromers move into the exposed area of the lens. The associated swelling causes precise shape and power changes. Light treatment focused on the center of the LAL increases curvature and power, while treatment of the peripheral areas flattens the center and decreases power. When the desired refractive outcome is achieved, the entire lens is irradiated and locked in. After that, no further adjustment is possible.

Mechanism of Action

PCLI—Chehalis, WA

Happy, friendly and polite, Mark Maraman’s exuberant, caring personality infects those around him. Born in Lincoln, Nebraska, Mark grew up in this midwestern city playing sports with the neighborhood kids. He enjoys basketball, traveling, hiking, golfing, snow skiing and spending time with his family. Mark and his wife Kendra, a nutrition and fitness specialist, live in Olympia, Washington. They have two sons—Lucas and Reid.

Mark Maraman, OD

 

 

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ABOUT THE AUTHOR

Light Adjustments

Precise UV irradiation of the lens is done in an office visit with an instrument called a Light Delivery Device (LDD). Irradiation is spatially controlled to deliver a pattern based on the patient’s post-operative refraction and their desired target outcome. Adjustments to the lens can be made in 0.25 diopter increments.

The LDD is FDA approved to correct +/- 2.00 diopters of sphere and 0.75 to 2.00 diopters of astigmatism in the IOL. However, higher degrees of adjustment are possible in certain circumstances.

Patient Experience

With the LAL, lens extraction and IOL implantation are the same as routine cataract surgery. But post-operative care is more involved:

  • Patients receive special UV protective glasses to wear during waking hours until the final prescription is locked in. This typically takes 4 to 6 weeks and is necessary to avoid unintended reshaping of the IOL due to environmental sources of UV light. Our post-op kit includes three pairs of glasses: clear, tinted, and reading.
  • To obtain precise refractive outcomes, patients undergo 1 to 3 adjustments and 1 or 2 lock-in treatments. Each treatment takes 40 to 120 seconds and is performed in an exam-room setting.

​

The Results

An FDA study of 600 patients found that those who received the LAL were twice as likely to achieve 20/20 uncorrected vision at six months as those who received a standard monofocal IOL.

​20/16 or better30.2%9.3%20/20 or better70.1%36.3%20/25 or better91.6%60.6%20/40 or better99.7%90.2%UCVARxSight LALMonofocal IOL

Most studies of standard monofocal IOLs in normal eyes show targeted manifest refraction spherical equivalent (MRSE) is accomplished with the following results:

  • About 90% are within 1.00 diopter of target
  • About 80% are within 0.50 diopters of target

The FDA pivotal trial for RxSight LAL compared targeted MRSE of this new lens with standard monofocal IOLs. These are the results:

  • 99.5% of LAL cases were within 1.00 diopter of target vs. 96.9% of standard IOL cases
  • 92.1% of LAL cases were within 0.50 diopters of target vs. 83.4% of standard IOL cases

Precision Benefits

Patients have unique expectations of what their vision will be like after cataract surgery. With traditional IOLs, we can be very close to our intended target. Yet, some people are underwhelmed with their results. Additionally, we can be off-target due to a variety of pre-operative conditions and measurement limitations. When more correction is needed, we have the option of lens exchange or laser vision correction. However, both come with potential risks and the stress of undergoing another surgery.

The LAL allows us to adjust lens power after implantation, when patients are using their new vision in everyday life. So we can help them customize their outcome. Those who desire monovision can benefit greatly from this technology. Likewise, patients who have had previous refractive surgery (RK, PRK, or LASIK) can benefit from this lens. With a standard IOL, they would have greater risk of residual refractive error and dissatisfaction.

Contraindications

LALs and light adjustments are contraindicated for:

  • Patients who have difficulty fixating
  • Patients with a history of ocular herpes simplex virus
  • Patients with macular disease (relative)

If systemic medications that increase UV sensitivity are being used, they will need to be discontinued a week or so before light adjustments.

Challenges

One challenge we have encountered is assuring that patients’ pupils dilate enough for light adjustments. The lens optic is 6 mm and must be completely visible, so patients need to dilate to 7 mm.

With frequent dilation in the post-operative period, some patients may suffer pharmacological dilation fatigue. If this occurs, we can space the light-adjustment treatments further apart, use stronger mydriatics, or both.

Final Thoughts

The new LAL ushers in a revolutionary era of technology. For the first time, we can modify an IOL after surgery with precision like no other. We believe this is just the beginning for advancements in modifiable IOLs.

Further improvements are expected with the RxSight LAL. And in the years to come, we will likely see the introduction of other novel systems, such as refractive index shaping. Future iterations should allow for even greater customization—expanding those treatments to obtain extended focus or multifocality within the IOL and treating higher-order aberrations of the visual system. The future is bright, and I am excited to see what comes next!

Questions

If you have questions, feel free to contact any of our optometric physicians. We’re always happy to assist.

WATCH our patient education video.

WATCH an OD talk about her LAL experience.

View Video

FROM THE EDITOR

Being able to adjust the refractive power of a patient’s lens implants after cataract surgery—once the eye has healed—seems like a sci-fi dream. But it is now a reality! With a revolutionary lens from RxSight, we can make repeated adjustments allowing patients to experience different visual outcomes. In this issue, my colleague Mark Maraman discusses this exciting technology.

As always, enjoy!

Ami Halvorson, OD

PCLI—Portland, OR

LALs at PCLI

Light adjustable lens implants are now available at our offices in:

Bellevue, WA

Chehalis, WA

Portland, OR

Boise, ID

 

Note from the editor

Our mission is to provide the best possible comanagement services to the profession of optometry. If we can help with anything, please be in touch.

CORPORATE OFFICE

Pacific Cataract and Laser Institute

2517 NE Kresky Ave., Chehalis, WA 98532

800.888.9903

pcli.com

By Mark Maraman, OD

PCLI—Chehalis, WA

Precise Customized
Vision with

 Light Adjustable

 Lens

Light Adjustments

Precise UV irradiation of the lens is done in an office visit with an instrument called a Light Delivery Device (LDD). Irradiation is spatially controlled to deliver a pattern based on the patient’s post-operative refraction and their desired target outcome. Adjustments to the lens can be made in 0.25 diopter increments.

The LDD is FDA approved to correct +/- 2.00 diopters of sphere and 0.75 to 2.00 diopters of astigmatism in the IOL. However, higher degrees of adjustment are possible in certain circumstances.

​

Patient Experience

With the LAL, lens extraction and IOL implantation are the same as routine cataract surgery. But post-operative care is more involved:

  • Patients receive special UV protective glasses to wear during waking hours until the final prescription is locked in. This typically takes 4 to 6 weeks and is necessary to avoid unintended reshaping of the IOL due to environmental sources of UV light. Our post-op kit includes three pairs of glasses: clear, tinted, and reading.
  • To obtain precise refractive outcomes, patients undergo 1 to 3 adjustments and 1 or 2 lock-in treatments. Each treatment takes 40 to 120 seconds and is performed in an exam-room setting.

​

The Results

An FDA study of 600 patients found that those who received the LAL were twice as likely to achieve 20/20 uncorrected vision at six months as those who received a standard monofocal IOL.

​20/16 or better30.2%9.3%20/20 or better70.1%36.3%20/25 or better91.6%60.6%20/40 or better99.7%90.2%UCVARxSight LALMonofocal IOL

Most studies of standard monofocal IOLs in normal eyes show targeted manifest refraction spherical equivalent (MRSE) is accomplished with the following results:

  • About 90% are within 1.00 diopter of target
  • About 80% are within 0.50 diopters of target

The FDA pivotal trial for RxSight LAL compared targeted MRSE of this new lens with standard monofocal IOLs. These are the results:

  • 99.5% of LAL cases were within 1.00 diopter of target vs. 96.9% of standard IOL cases
  • 92.1% of LAL cases were within 0.50 diopters of target vs. 83.4% of standard IOL cases

Precision Benefits

Patients have unique expectations of what their vision will be like after cataract surgery. With traditional IOLs, we can be very close to our intended target. Yet, some people are underwhelmed with their results. Additionally, we can be off-target due to a variety of pre-operative conditions and measurement limitations. When more correction is needed, we have the option of lens exchange or laser vision correction. However, both come with potential risks and the stress of undergoing another surgery.

The LAL allows us to adjust lens power after implantation, when patients are using their new vision in everyday life. So we can help them customize their outcome. Those who desire monovision can benefit greatly from this technology. Likewise, patients who have had previous refractive surgery (RK, PRK, or LASIK) can benefit from this lens. With a standard IOL, they would have greater risk of residual refractive error and dissatisfaction.

Contraindications

LALs and light adjustments are contraindicated for:

  • Patients who have difficulty fixating
  • Patients with a history of ocular herpes simplex virus
  • Patients with macular disease (relative)

If systemic medications that increase UV sensitivity are being used, they will need to be discontinued a week or so before light adjustments.

Challenges

One challenge we have encountered is assuring that patients’ pupils dilate enough for light adjustments. The lens optic is 6 mm and must be completely visible, so patients need to dilate to 7 mm.

With frequent dilation in the post-operative period, some patients may suffer pharmacological dilation fatigue. If this occurs, we can space the light-adjustment treatments further apart, use stronger mydriatics, or both.

Final Thoughts

The new LAL ushers in a revolutionary era of technology. For the first time, we can modify an IOL after surgery with precision like no other. We believe this is just the beginning for advancements in modifiable IOLs.

Further improvements are expected with the RxSight LAL. And in the years to come, we will likely see the introduction of other novel systems, such as refractive index shaping. Future iterations should allow for even greater customization—expanding those treatments to obtain extended focus or multifocality within the IOL and treating higher-order aberrations of the visual system. The future is bright, and I am excited to see what comes next!

Questions

If you have questions, feel free to contact any of our optometric physicians. We’re always happy to assist.