Recent increased marketing efforts have led some consumers to question if a new procedure called ”Intralase LASIK" is somehow a superior option to standard LASIK or PRK.
The standard method of LASIK surgery entails using a highly precise surgical instrument called a microkeratome to create the corneal flap.
IntraLase LASIK (sometimes referred to as bladeless, blade-free, or all-laser LASIK) is a modified approach which entails creating the corneal flap with a femtosecond laser.
Once the flap is created, the traditional LASIK laser system (an Excimer laser) is used to reshape the cornea to correct the patients vision.
Thus, with Intralase LASIK, two lasers are used during the procedure.
you should know that with PRK no flap or cut is made. PRK is blade free, flap free, pain free under the laser, no cut Laser vision correction for safer, better results.
During the PRK procedure it is painless and it is a much shorter procedure.
No form of LASIK is recommended for thinner corneas and sometimes only PRK is advised.
Lack of improved results A recent study conducted at the Mayo Clinic concluded there were no significant improvements in the results between patients who had LASIK performed with the microkeratome and patients who had Intralase LASIK. When compared side-by-side, the Intralase procedure was no better than the traditional method. For more information, see: http://www.mayoclinic.org/news2006-rst/3356.html. The results of comparing Conventional PRK visual results compared to LASIK visual results demonstrate that PRK has a 2% higher probability to achieve 20/20.http://www.mayoclinic.org/news2006-rst/3356.html
Longer surgical time After the corneal flap is created by the femtosecond laser in the Intralase procedure, the surgeon must wait approximately 12 minutes before lifting the flap and beginning the treatment with the Excimer laser. Creating a flap with a microkeratome takes seconds, and the flap can be lifted immediately.
Some surgeons believe the significantly longer treatment time required in the Intralase procedure increases a patient’s chances for side effects, as well as the potential for the surface of the eye to become dry, which can cause variability in results. If air bubble formation in the substance of the cornea or in the anterior chamber interferes with the Excimer LASER tracker or iris registration, the patient has to wait for the air bubbles to dissipate. This will prolong the Procedure (more about this below).
Increased trauma to the eye The way the Intralase laser cuts a flap in the stroma of the cornea is first to lay down small circular spots of laser energy side by side in the same plane(called the flap bed) within the cornea’s substance (called the stroma) so that the small circular spots just touché each other. This is done to cover approximately a 9 millimeter diameter of the cornea. Second, a circular (9 millimeters in diameter) vertical cut (the flap edge) is then cut by the laser, leaving approximately 2millimeters of uncut corneal stroma so a hinge is created.
The first process leaves small residual “bridges” of uncut corneal stromal bed tissue between the small circular spots cut by the laser. Thus in the Intralase procedure, the flap created by the femtosecond laser is not completely separated from the underlying bed tissue. Surgeons report that small residual “bridges” of tissue are still connected after the procedure, and that these must be snapped or torn apart manually as the flap is lifted. This increased trauma to the underlying tissue can put a patient at risk for inflammation and other complications.
Increased risk of light sensitivity Some patients have reported a previously undocumented side effect following the Intralase procedure – increased light sensitivity. Surgeons have termed this condition “delayed onset photophobia” (DAP) or “transient light sensitivity” (TLS).
Increased cost to the patient Because two lasers are needed to perform the Intralase LASIK surgery, vision centers must invest in two separate and equally expensive devices. The centers are then forced to pass on this increased cost to consumers. Patients generally pay hundreds of dollars more per eye for an Intralase procedure versus PRK or the LASIK procedure performed with a microkeratome
Much more pain The Intralase procedure is much more painful when the femtosecond laser suction ring and aplanator is placed on the eye. To make the femtosecond Laser cut the dome shaped cornea has to pressed or squashed into planer surface by the laser's suction ring and aplanator so the femtosecond laser pulses are all placed or delivered at the same plane in the cornea.
This is something that all laser techs and doctors notice but don't place in their advertisements about the femtosecond laser. LASIK with a microkeratome is less painful. PRK is bladeless, flapless and during the procedure it is painless and it is a much shorter procedure.
Increased difficulty to lift the flap after one year for enhancements Increased difficulty lifting the original femtosecond laser flap after one year for the purpose to doing enhancements has been reported by all users of the laser, if they have used the laser more than one year. To do an enhancement the users have been reporting that a new circular vertical cut has to be placed just inside the original circular vertical cut (the edge of the flap).
This new flap edge is smaller in diameter than the original flap edge. This can lead to problems if the Excimer laser treatment falls out side of this smaller second flap edge. So you have to go under the femtosecond laser again for the purposes of cutting and lifting the flap for enhancements. LASIK flaps done with a microkeratome can be lifted even out to 10 years. Any flap lift is a setup for epithelial ingrowth. PRK enhancements require no flap to be lifted, since there is no flap. All that is done is that the laser treatment is applied to the original treatment bed on the cornea.
Increased risk of air bubbles remaining forming in the cornea High risk of air bubble formation in the substance of the cornea that may require messaging of the cornea to dissipate the air bubbles so the Excimer laser can do the correction. The Excimer LASER’s tracker and iris registration will not engage if there are too many bubbles in the corneal substance or stroma.
Technicians working in LASER centers that have the Femtosecond LASER, tell us that the messaging of the cornea to help speed the dissipation of the air bubbles is painful. Some times the operator has to place the patient in a waiting or holding area to wait for the bubbles to dissipate. This prolongs the procedure time.
Increased risk of air bubbles remaining forming in the anterior chamber High risk of air bubbles forming in the anterior (front) chamber of the eye. The patient has to wait around while the air bubbles dissipate. The air bubbles can interfere with the laser tracker and iris registration (automatic functions of the Excimer laser). This prolongs the procedure time. Increased risk of air bubbles remaining forming in the anterior chamber High risk of air bubbles forming in the anterior (front) chamber of the eye. The patient has to wait around while the air bubbles dissipate. The air bubbles can interfere with the laser tracker and iris registration (automatic functions of the Excimer laser). This prolongs the procedure time.
Slower visual recovery Although femtosecond laser technology and results continue to evolve, many investigators have demonstrated the visual recovery is slower when the LASIK flap is cut with the IntraLase compared to the microkeratome. The investigators think that this is due to more flap edema and perhaps a rougher interface surface.
Investigators reason that the flap created by the femtosecond laser is not completely separated from the underlying tissue. Surgeons report that small residual “bridges” of tissue are still connected after the procedure, and that these must be snapped or torn apart manually as the flap is lifted. They think that this trauma causes edema and rougher interface surfaces, for the Excimer laser to work on. Ophthalmology Times, October 1st 2004, Dr. Richard Duffy.
Corneal endothelial cell density after femtosecond thin-flap LASIK and PRK for myopia: a contralateral eye study.
CONCLUSIONS: No statistically significant change was noted in endothelial cell density following either PRK or thin- flap LASIK for the treatment of myopia. Furthermore, no statistically significant difference was found between the two groups out to 3 months postoperatively, indicating that thin-flap LASIK is as safe as PRK with regards to endothelial health.