FEMTOSECOND LASER CATARACT SURGERY
What we are going to learn in this article
What is Femtosecond Laser Cataract Surgery
Cataract Surgery assisted by Femtosecond lasers is called femtosecond laser surgery or femtosecond laser assisted surgery (FLACS). Femtosecond lasers are different than excimer lasers used in Lasik Eye Surgery.
Femtosecond lasers for Cataract, Prelex and Pi surgeries have increased safety and precision for vision correction procedures. The Femtosecond laser is remarkable because it can make perfect openings in the lens of the eye as well as make relaxing incisions to correct astigmatism. In addition, the Femtosecond laser has an amazing technology where it can break the lens of the eye into multiple pieces of desired size and shape: therefore making it easier to remove the lens pieces with the least amount of energy.
Fig 1 Engaging the docking mechanism. Patient looks at the central red light. Corneal cuts from previous radial keratotomy are visible.
The laser procedure, lasting a few minutes, is simple and easy. It begins with the patient being wheeled into the laser suite. Everything to be operated upon is confirmed per protocol before the surgery. Drops are then placed in the eye to dilate as well as numb the eye. A medical marking pen is then used to make specific markings on the eye. Next, an eye retainer is placed in the eye to keep the eyelids separated and the laser is positioned over the patient. This is a non-invasive procedure and therefore the eyes will not be prepped with any installation of drops that can sting, such as Iodine which can interfere with the performance of the laser. During the quick procedure the patient will be addressed to look at a blinking red light. This red light is very bright and can even be seen through advanced cataracts. The docking mechanism is then engaged and the Femtosecond laser works to carry out the instructions previously programmed by the surgeon. The laser will first make an opening in the capsulorhexis (lens bag) and then followed by a patterned breakup of the lens. The laser can cut the lens into 2, 4 or 6 pieces, or it can even be chopped into cubes of various sizes like 250 or 500 microns, depending on the commands given to the laser. Also, the center core may be delineated too and the depth of these lenticular cuts can again be controlled by the laser. Next, one or two precise incisions are made to fix the astigmatism. The length and the distance from the center and the depth of each astigmatic keratotomy incision can be coordinated independently. Lastly, one or two side-port openings and the main wound is made. At all times during the procedure, a real-time image of the lens and cornea are displayed on a monitor. After the laser has done its job, the patient is taken to the operating room where the surgeon will remove the lens fragments left in the eye and insert a new Pi (lens).
Advantage and Disadvantages of Laser Assisted Cataract Surgery
There are several great advantages of femtosecond laser cataract surgery. The surgeon can design the exact openings and pattern of breaking up the lens pieces. The plan for the laser is generated by performing various tests including obtaining a colored image of the surface of the eye and measuring the length of the eye. A detailed clinical slit exam is also necessary because the surgeon will need to asses the thickness, color, and hardness of the lens. Pupil dilation, any weakness in the support of the lens or imperfections on the lens capsule has to be accounted for.
All the content obtained during an eye exam leads to a plan of action. This arrangement can then be entered into the software of the Femtosecond laser and any modifications can be programmed. In special cases, the femtosecond laser may be the best choice. If the support of the lens is weak, working the capsule by hand can lead to further weakening of the support. Therefore in this scenario laser cataract surgery would be safer as it does not stress the lens capsule or its support.
The same rings true in extreme cataract cases where trauma has weakened the lens support. The Femtosecond laser is advantageous in making openings in the lens of the eye with a thick capsule. In people with white or red cataracts the Femtosecond laser also holds an advantage. For these patients the capsule needs to be stained manually to be visualized and still it may be difficult to get a good view of the capsule. The Femtosecond laser overcomes this as it utilizes imaging in real time and cutting vertically deflects any rubbing on the Zonular support system.
The opening in the capsule can even be contained by the laser down to a tenth of a millimeter and the diameter can be made to change over a great range, for example 4.2 to 6 mm. The Femtosecond laser systematically makes an opening of the desired shape and diameter, which is challenging to create manually. An experienced surgeon may be very experienced in making the openings but sometimes the shape may be too eccentric or oval. When embedding Pi in eye, the more circular, central, and defined the opening the better it is. For Restor and Tecnis multifocal lens, the openings are somewhat smaller than for Crystalens.
Specifically with the Crystalens implant, a symmetrical opening is essential. Otherwise, possibilities of torque in the lens known as Z-Syndrome may develop. If the bag were to rip, Crystalens cannot even be embedded. The Femtosecond laser’s exactness is equally helpful in wound creation. The precise openings permit the entry and exit of instruments and the insertion of the Pi without excessive stress and consequently unintended enlarging of the wound, preventing any wound leakage at the end of the surgery and facilitating faster healing.
Fig 3 and Fig 4 Compare the programmed and actual corneal incisions and cuts in the lens. Air bubbles can be seen in Fig 8.4. The depth and width of the lens cuts is displayed in yellow.
The splitting of the lens by the Femtosecond laser is valuable because it is done without any stress on the capsular bag or the Zonular support system. The deepness of the cuts in the lens can be precisely controlled in real time. The energy is delivered from the bottom towards the top permitting gas, created by transition of the lens material into plasma, to escape as well as allowing the subsequent beam to work without hindrance from gas bubbles. In dense cataracts, the bottom is challenging to perceive so the capsule can be incidentally ruptured. Real-time image display with the Femtosecond laser allows the ability to be precise therefore allowing the surgeon to avoid the bottom of the bag. This is of tremendous benefit when using the laser for cataract or Prelex procedure.
Breaking apart hard lenses is time consuming with traditional sound wave technology. Femtosecond lasers lessen time and energy required to accomplish the breaking of the lens. Further advances in laser technology will be even more assertive in removal of cataracts. The age of robots is red-hot and approaching. Maybe one day robots could safely perform Cataract or Prelex surgery. As of the moment skilled cataract surgeons are still needed. The technology is advancing at a speedy pace.
Disadvantages of Laser Assisted Cataract Surgery
It increases the time required for total cataract eye procedure. There are two steps. A person has to lie still for few minutes under the docking of femtosecond, lasers may cause redness of the eye, and there is increased cost.
Different Lasers available for Cataract Surgery
There are many lasers available for Femtosecond laser cataract surgery The following are FDA approved.
• Lensx Laser– Alcon (OCT or Ocular Coherence Tomography based)
• Catalys Laser – Optimedica (OCT based)
• Victus – Bausch & Lomb (Real time OCT based)
• Lensar – (Scheimpflug based)
A typical question is, which is the best? Each laser has its own strengths and benefits. It is important that the Pi in eye surgeon has access to more than one of these lasers so he or she can select the best for the particular eye.
Cost of Laser Cataract Eye Surgery
Femtosecond laser cataract surgery requires imaging and calculations. Ocular Coherence Tomography or OCT imaging is required to plan the cataract eye procedure with the laser. OCT is like a colored MRI. It scans the structures of the eye in great detail. Only than the precision of the femtosecond lasers can be employed. This technology is expensive. Most surgeons charge between 1800 to 3200 Dollars per eye. At our Los Angeles Centers, we offer 36 month no interest no money down affordable monthly installments.
Insurance Coverage for Laser for Cataract Surgery
The Medical and Visual insurances do not cover for the diagnostic imaging. The Center for Medical Services came out with a ruling which outlines this policy. Still it is a good idea to double check with your insurance company. If you want us to find the exact coverage for femtosecond laser cataract surgery please send us a copy of your insurance card by fax to (805) 230 2199 or Please take a picture of the insurance card with your smart phone and text it (310) 482 1240.
By Rajesh Khanna, MD