Laser Cataract Surgery

By Vance Thompson, MD

The femtosecond laser technology that brought new levels of safety, accuracy and predictability to LASIK flap creation is also advancing cataract surgery. In our office, we call the procedure Refractive Laser-Assisted Cataract Surgery (ReLACS), but it also is known generally as laser cataract surgery.

The Cataract Incision

Traditional cataract surgery is one of the most frequently performed surgeries and also one of the most safe and effective, with predictable outcomes. It is highly dependent on surgeon skill, volume and experience.

In traditional cataract surgery, the eye surgeon uses a hand-held metal or diamond blade to create an incision in the area where the sclera meets the cornea. The goal in creating this incision is to go a partial depth vertically, then go horizontally in the cornea about 2.5 mm and then enter into the eye. Then the surgeon can break up and remove the cataract, which is located right behind the pupil. Next an intraocular lens (IOL) is inserted and implanted, to replace the cloudy natural lens.

The reason cataract incisions are created in a two- or three-plane fashion is so they will self-seal when surgery is complete, allowing for a no-stitch approach.

With the laser approach to cataract surgery, the surgeon creates a precise surgical plan with a sophisticated 3-D image of the eye called an OCT (optical coherence tomography). The goal is to create an incision with a specific location, depth and length in all planes, and with the OCT image and a femtosecond laser, it can be performed exactly without the variable of surgeon experience.

Optical coherence tomography is an imaging technology that helps your cataract surgeon to plan the location and depth of incisions made during a laser-assisted cataract surgery procedure. OCT scans offer high-resolution and even cross-sectional images, to make the cataract surgery as precise as possible. (Images: Vance Thompson, MD)

This is important not only for accuracy but also for increasing the likelihood that the incision will be self-sealing at the end of the procedure, which reduces the risk of infection.

The Capsulotomy

The eye's natural lens is surrounded by a capsule that is very thin and very clear. In cataract surgery the front portion of the capsule is removed in a step called thecapsulotomy, to gain access to the cataract.

It is important that this capsule not be damaged during the cataract surgery, because it must hold the artificial lens implant in place for the rest of the patient's life.

In traditional cataract surgery, the surgeon creates an opening in the capsule with a small needle and then uses that same needle or a forceps to tear the capsule in a circular fashion.

The opening should be a continuous tear that is 5 to 6 mm in diameter and well-centered for optimal implant fit.

Studies have already shown that this very important capsulotomy step works better with the laser in terms of accuracy and reproducibility.

Studies have also shown that laser capsulotomies enable better centering of the intraocular lens (IOL), and IOL positioning is a significant factor in determining final visual outcomes.

Removal of the Cataract

After the capsulotomy, the surgeon now has access to the cataract to remove it. In traditional cataract surgery, the ultrasonic device that breaks up the cataract is inserted into the incision. During this phacoemulsification procedure, the ultrasound energy can lead to heat buildup in the incision, which sometimes can burn the incision and negatively affect the visual outcome by actually inducing astigmatism.

An incision burn also has a higher chance of leaking and sometimes needs multiple sutures to close. The smaller the incision we use, the more this issue is important to consider.

The laser, on the other hand, softens the cataract as it breaks it up. By breaking up the cataract into smaller, softer pieces, less energy should be needed to remove the cataract, so there should be less chance of burning and distorting the incision.

Using the laser should also result in less chance of capsule breakage. After the calculation of the proper implant power, there is no step more important for visual outcome than preservation of the capsule that the natural lens sat in. This capsule is as thin as cellophane wrap and is important to leave undamaged so that it can hold the artificial lens implant in the proper position for the best ability to focus.

The reduced energy of the laser may also make the procedure safer to the inner eye, which reduces the chance of certain complications, such as a detached retina.

Astigmatism Correction at the Time of Cataract Surgery

Especially with advanced intraocular lenses that provide good vision without glasses after cataract surgery, it is important that the surgery results in minimal astigmatism. Examples of these advanced lenses are presbyopia-correcting multifocal IOLs and accommodating IOLs.

Because astigmatism involves the cornea being more curved in one axis than the other (like a football shape), incisions can be used in the more curved axis to reduce the astigmatism so the cornea has a rounder shape (like a basketball). The procedure is called astigmatic keratotomy or AK.

Surgeons perform AK free-hand with a diamond blade, and it is quite effective in reducing astigmatism.

During refractive laser-assisted cataract surgery, the OCT image can be used to plan the AK incisions in a very precise location, length and depth, and then the laser accurately creates them. Since the laser minimizes the variables involved, the AK procedure becomes more accurate and reproducible.

Cost of Laser Cataract Surgery

Refractive laser-assisted cataract surgery costs more than conventional options. The laser itself can cost the surgeon approximately $300,000 to $500,000, and additional costs are associated with using and maintaining the device.

Extra costs associated with laser cataract surgery are unlikely to be covered by Medicare or private health insurance. Fees vary from one cataract surgeon to another, but it is likely you would pay a few hundred dollars extra per eye out-of-pocket for a laser-assisted procedure.

Cataract surgeons who use lasers say that their advantages are especially evident when it comes to high-tech, premium implants such as presbyopia-correcting multifocal IOLs and accommodating IOLs. The advantages can include better lens placement and therefore more accurate visual outcomes.

A New Era in Cataract Surgery

An exciting aspect of laser cataract surgery is the concept of optimization — the continuous improvement of a technique or technology.

One example is the incision. When it is made with a human hand guiding a blade, there are limitations. But a laser can make a perfect zigzag incision that interlocks precisely and improves the chance of self-sealing, and this is an advancement over traditional manual technology.

Once a laser enters the surgical arena the opportunities to optimize are endless. We are just in the beginning of this refractive laser-assisted cataract surgery journey, and precision improvements will arrive quickly.

Status of Laser Cataract Surgery Systems in the United States

Here are the principal laser-based surgical systems that are either FDA-approved or still in development for laser cataract surgery:

This LenSx femtosecond laser system has laser data entry at left, a joy stick control and an OCT screen at right, which offers the surgeon all-important guidance during laser-assisted cataract procedures. (Images: Alcon)

• LenSx. The LenSx (Alcon) was the first femtosecond laser system to receive FDA approvals for cataract procedures. The approvals involve three aspects of cataract surgery: creating the anterior capsulotomy that involves making a circular incision within the eye, fragmenting the cataract and making laser incisions on the corneal plane.
• LensAR. The latest LensAR Laser System (LensAR, Inc.) received FDA approval for anterior capsulotomy and lens fragmentation in June 2012, and for performing corneal incisions for cataract surgery in December 2012. Its FDA approval for arcuate incisions (made on the periphery of the cornea) came in April 2013.
• Catalys. The Catalys Precision Laser System (OptiMedica) also has FDA approval for capsulotomy and lens fragmentation.
• iFS. Abbott Medical Optics received FDA approval for its iFS Femtosecond Laser to create bow-shaped or curved arcuate incisions in cataract surgery. The device had already been used for several years to create the flap in all-laser LASIK.
• Victus. The Victus Femtosecond Laser Platform (Technolas Perfect Vision in partnership with Bausch + Lomb) was launched in Europe in September 2011 and received FDA approval in August 2012. The Victus is a multiple-use femtosecond laser system and is cleared for: anterior capsulotomy during cataract surgery; corneal flap creation during LASIK surgery or other treatment requiring initial lamellar resection; and arcuate corneal incisions.
• Femto LDV Z6. This device by Ziemer Group has received FDA approval for certain eye surgeries, but not yet for laser cataract surgery.

Conclusion

It is important to put this new technology into proper perspective. Traditional cataract surgery is very effective and successful. People who do not want to invest out-of-pocket money in laser cataract surgery can still feel confident about the traditional approach.

But for those who want the best possible vision, the laser approach is appealing. A more accurate incision, capsulotomy and astigmatic correction will help to achieve their goal of less dependence on glasses after cataract surgery.

Keep in mind that even though the early results of laser cataract surgery are promising, this is newer technology that deserves in-depth research and discussion with your doctor so that you can make the best possible decision for your situation.