The New iFS Advanced Femtosecond Laser: Better Technology, Better Results, Better Vision
In life, all other things being equal, faster is better. The first experimental femtosecond lasers operating at 2 kHz took approximately 5 minutes to make a LASIK flap. At Will Vision and Laser Centers, our advanced fifth generation iFS laser operating at 150 kHz can now make a superior flap in just 8 seconds.
Speed Increases Comfort and Safety
There are several advantages to higher laser speed. First, the time that the vacuum ring is on the eye is reduced. Less time under suction means less risk of losing vacuum during a procedure and less time that the eye experiences an elevation of intraocular pressure.
From the patient’s perspective, the vacuum ring is the most uncomfortable part of the procedure, so less time under suction means significantly less discomfort. Also, reducing time under vacuum diminishes the potential for superficial hemorrhages on the eye surface. Although these subconjunctival hemorrhages are cosmetic and do not affect vision, patients understandably don’t appreciate them.
Lower Energy to the Eye Tissue
At Will Vision and Laser Centers, our iFS laser is approximately 2½ times faster than the previous 4th generation system. This increased speed allows Dr. Will to markedly reduce the energy used in each laser pulse. Effectively, we can bring the laser spots closer together and reduce the energy to each pulse. The result of this change is that there is significantly less local injury to the tissue surrounding the area where the laser pulse is focused. Less local energy allows the tissue to come through the surgery with less injury, fewer thermal effects, less swelling and simply provides for healthier and happier corneas.
Healthier and happier corneas heal more predictably and the vision clears more rapidly.
The higher the energy in each laser pulse, the higher the chance of causing a bubble layer to occur in the remaining tissue. Although these bubbles have no adverse effect on tissue healing, they can interfere with eye tracking systems and make the LASIK flap more difficult to lift. With the new iFS laser system and lower energy, we only rarely observe an opaque bubble layer.
With older femtosecond laser systems that use higher laser pulse energies, there is the rare patient who will demonstrate a transient sensitivity to light postoperatively. Although this side effect is generally easily treated with eye drops, Dr. Will’s experience suggests that the incidence of this light sensitivity syndrome is reduced with the iFS due to our ability to use a significantly lower pulse energy.
Enhanced Surface Smoothness
Clearly, one of the well-known properties of the optics of the eye is that the smoother the optical surface the better the visual quality. Each generation of femtosecond laser has delivered smoother tissue dissection primarily due to faster speed and closer pulse separation.
The fifth generation iFS laser at Will Vision and Laser Centers delivers superior bed smoothness compared to microkeratomes, previous generations of Intralase technology as well as competing femtosecond platforms. When studied under very high magnification using scanning electron microscopy, the iFS laser clearly delivers a smoother tissue surface and a superior optical surface compared to any other surgical modality.
Superior Healing and Corneal Strength
One of the major innovations that the new iFS system provides is the ability to create an inverted bevel architecture at the edge of the flap. Like a “tongue-in-grove” carpentry joint, the reverse bevel edge fits perfectly. This improved edge architecture provides the patient with several distinct advantages.
First, the side-cut angle provided by femtosecond lasers is believed to prevent the occurrence of epithelial ingrowth. Compared to a mechanical microkeratome, femtosecond lasers have always enjoyed a lower incidence of this unwanted complication. In our experience, this effect will be improved by this new reverse bevel modification in flap edge architecture.
Secondly, in both human eye studies and rabbit eye studies the reverse bevel has been determined to create superior healing and corneal strength. In human eyes in a study comparing the reverse bevel 140-degree sidewall to a standard 70 sidewall, the reverse bevel healed stronger. Similarly, in a rabbit eye study, 3X more force was required to lift a 140-degree bevel iFS flap compared to a microkeratome created flap.
At Will Vision and Laser Centers we continue to invest in the most advanced technologies because we believe that fewer potential complications and a stronger eye represent very significant advantages for patients undergoing elective LASIK eye surgery.
Oval Flap Advantages
An additional major innovation for the new iFS laser is its ability to create oval flaps. Virtually every cornea is oval shaped so this new feature allows Dr. Will to better match the flap design to the normal eye shape. This shape matching allows Dr. Will to preserve corneal nerves as well as maintain better biomechanical stability by severing fewer collagen fibrils.
Perhaps the most significant advantage of the oval flap is that it allows Dr. Will to better match and align the flap size and location to the best treatment area on the cornea, particularly with astigmatism which requires an oval treatment profile. In addition, in more complex cases like farsightedness and astigmatism, the oval flap architecture improves the ability of Dr. Will to locate the flap hinge so that it does not interfere with the delivery of the ideal treatment.
Advanced Surgical Controls
At Will Vision and Laser Centers, we have consistently led the industry in the adoption of the most advanced electronic innovations for the sole purpose of improving surgical results. The new iFS system continues that commitment by delivering one of the most innovative technological developments in computer technology today, providing an enhanced dual “heads-up” touch screen video display for both the surgeon and assistant.
Better Technology, Better Results, Better Vision
Smoother optical surfaces, faster surgery with fewer complications, superior healing, greater flap stability and a stronger eye provide our patients with the best opportunity to have great clear vision. At Will Vision and Laser Centers we believe that excellent surgical results cannot be attained using yesterday’s technologies. We invest in our patients and our consistently excellent visual results validate that commitment.