iFS™ Technology Improves Flap Nerve Apposition
Femtosecond Laser Flap for LASIK Surgery
Creating the flap during LASIK surgery with a femtosecond laser is more precise than using a Microkeratome. It provides:
Better control of flap thickness
Diameter choice of the flap
Better centration of the flap
The femtosecond laser flap formation provides less disruption of the corneal structures and architecture.
iFS Femtosecond Laser
The iFS Laser has some other advantages in that the surgeon can customize other aspects in creating the flap during LASIK surgery. The shape of the flap can be changed. There is new theory that an oval flap may be better as it conforms to the shape of the cornea. The cornea is wider at the horizontal axis versus the vertical axis. The side-cut angle of the flap, hinge size, and location can be manipulated with the iFS Laser.
After the LASIK is performed, approximating the edge of the flap is important and may help with aligning the nerves in the cornea. A reverse side-cut or Zig-Zag creates a flap design that helps align the flap and therefore the nerves in the cornea.
Corneal Sensation and Dry Eyes Following LASIK
One of the most common problems or complaints of patients following LASIK surgery is dry irritated eyes. The loss of corneal sensation due to cutting of the nerves in the cornea leads to the development of dry eye syndrome in many patients. This causes the common complaints of dry eyes such as grittiness, foreign body sensation, itching, watering, dry sensation, redness, irritation, and blurred vision.
As the nerves regenerate, the dry eye symptoms improve over the first few months after surgery. There is a small minority of patients who continue to have dry eye complaits permanently.
Factors That Can Effect Corneal Sensation and Dry Eyes
The size of the flap can have an effect on corneal sensation with larger flap cutting more nerve fibers.
Thicker flaps cut more nerve fibers.
Hinge Size and Location
Larger hinges preserve nerve fibers. The location of the flap is important as there are more nerve fibers located in the horizontal axis. Placing the flap in the horizontal axis can preserve more nerve fibers.
The type of edge of the flap may help with realignment of the corneal nerves.
One of the most common factors LASIK surgeons have to handle after surgery is the complaint of dry eyes. Treatment of any dry eye syndrome that the patients may have before surgery is very important. The size, shape, thickness, flap location, and type of edge cut have an important role in improving the results for LASIK surgery. The iFS Laser provides the surgeon with the ability to design the flap in a manner that the surgeon feels is most appropriate for a particular patient.