Is IntraLase a Safer Alternative for Your Eyes?

Choosing LASIK surgery for vision correction is not the same as it was 10 or 12 years ago.  In 1994, when Baltimore ophthalmologist Anthony Kameen had LASIK surgery to correct nearsightedness and astigmatism, his options were not very extensive: a small mechanical blade, called a microkeratome, created a flap on his cornea, after which a conventional excimer laser was used to reshape the tissue underneath so that the cornea would be able to focus light directly on the retina, as it would in a normal eye.  That was, in a nutshell, the only way LASIK was performed then.  Now, of course, the technology is much more advanced including smoother and more precise lasers, allowing patients to achieve better vision than ever possible before.  The newest technological addition to Dr. Kameen's refractive surgery office is a machine called IntraLase, which allows patients to avoid operation via a metal blade, using a special laser that is used only for the purpose of flap creation.

IntraLase in Practice

Touted as "all-laser" LASIK, the most significant claim of the IntraLase machine is that it can greatly reduce the risk of flap complications associated with microkeratome created flaps.  When a microkeratome is used, there is the possibility that a flap will be cut too thin, will tear, or will not cut completely.  With IntraLase these possibilities are negated.  Dr. Trevor Woodhams has used the IntraLase system in his Atlanta office for the past two years and reports very few major complications, and a re-operation rate similar to that with a microkeratome, about 5%.  Dr. Kameen reports even better results during his year of use.  In fact he has only needed to do "touch-ups" on 6 of his approximately 960 procedures, compared to an 8-9% rate with the mechanical device.  Of this statistic he says, "I personally didn't believe it.  I thought it was just marketing hype.  I am a believer now."

However, this does not mean that it will eliminate flap problems, in fact flap wrinkles and other related problems are still possible, though less likely, with the IntraLase laser.  Proponents of the IntraLase created flap, such as Dr. Woodhams and Dr. Kameen, use the system for the majority of their LASIK patients, claiming that they can achieve better visual acuity while cutting down on the occurrence of major complications.  Detractors say that there is no clinically substantial evidence that better vision is possible or that such risks are significantly reduced, while surgery takes longer and additional complications are introduced.

How IntraLase Works

During flap creation, the IntraLase laser beam places a series of small bubbles inside the cornea, removing corneal tissue, and allowing the flap to be dislodged and exposing the cornea.  Because the surgeon can determine the depth and diameter of the flap, the result is a more precise and usually smoother cut.  With the laser, surgeons have better control, and even have the ability to make adjustments after beginning the cut.  While using IntraLase on one of his patients, Dr. Kameen realized halfway through that the flap wasn't centered correctly so he stopped, re-centered, then continued the cut.  This would not have been possible if he were using a mechanical blade.  In addition, many practitioners say that they can achieve better vision with IntraLase.  Dr. Woodhams says that recently about 94% of his patients are achieving 20/20 vision and all reach 20/30, though studies, he says, are ongoing.

The Learning Curve

The biggest knock against IntraLase is that it has an unacceptably high rate of late occurring photophobia (abnormal sensitivity to light).  Dr. Woodhams noticed this trend, and even stopped using the machine in his office for two months.  IntraLase made adjustments, introduced a new laser, and Dr. Woodhams began using the system again in August 2004 without the problems of photofobia.  He says, "I have been impressed with the way the company has been responsive to user complaints."

As with any device, there is also the learning curve factor.  Dr. Kameen had a short period during which the machine in his office had energy settings that were too high.  While he emphasizes that no one was hurt as a result of this miscalculation, there were instances of post-operative inflammation and additional patient discomfort.  Dr. Woodhams agrees that learning to get the energy set correctly is an issue for beginners.  He also says that the more you use it, the more you develop a softer touch, better accuracy, and even achieve better visual acuity for patients.

Supplemental Differences

Of course, not everyone agrees with Dr. Woodhams and Dr. Kameen's findings.  In a report published as a supplement to the November/December 2004 issue of Cataract and Refractive Surgery Today, studies showed that there were no significant differences in visual acuity and instances of higher order aberrations between eyes with IntraLase created flaps and eyes with flaps created by the Hansatome microkeratome manufactured by Bausch & Lomb.  In addition to not offering any statistically better outcomes, the report showed that IntraLase introduced its own possible complications including photophobia, inflammation, and a less-than-smooth stromal bed (the part of the cornea exposed after flap creation).  As mentioned above, however, some doctors believe that the risk of these complications can be avoided after significant experience and setting changes.  The additional negatives sighted by the report included a higher cost that is passed along to the patient at the price of about $250 per eye and a longer operating time. 

In contrast to this report, however, there have been several other findings suggesting that the IntraLase system does offer better vision along with lower instances of complications.  One, in fact, was published as the March 2004 supplement to Cataract and Refractive Surgery Today by Dr. Daniel Durrie, in which he stated, "the INTRALASE FS laser was at least equal to or better than the Hansatome in every category.  I consider these results impressive across the board."

A Case by Case Basis

Looking solely at report statistics, however, will probably not determine what option will offer the most benefits to a given patient.  IntraLase flap creation offers more potential benefits for specific patients, while for others it may not even be a good option at all.  For this reason, patients may be better served trying to answer the question "is IntraLase a better option for me" rather than, "is IntraLase better than a microkeratome?"

For patients who have had RK (radial keratotomy), a surgical refractive surgery, in the past, IntraLase cannot be used (other vision correction surgeries could make the use of laser flap creation undesirable as well).  In addition, patients needing only minor correction, especially patients with only mild myopia, or nearsightedness, may not necessarily find the benefits that IntraLase can offer them any greater than what a microkeratome can, and may view the extra money and longer surgical time as unnecessary.

On the other hand, Dr. Kameen will use only IntraLase on patients with any amount of hyperopia, farsightedness, never a microkeratome.  Because IntraLase offers better control and more flap precision, the flap is wider and is removed in a more symmetrical shape.  When hyperopia is corrected with LASIK, it is the periphery of the cornea that is treated, and the wider flap that IntraLase provides offers the possibility of better surgical correction.  In addition, IntraLase makes LASIK available to patients for whom it would not have been a good option before.  These types of patients include ones with high myopia or thin corneas.  Again, because flap creation can be tailored to meet the specifications of an eye individually, creating laser flaps in these patients can greatly reduce the risks and offer better possible vision.

IntraLase and Custom LASIK

IntraLase also seems to offer greater advantages when it is combined with wavefront-guided lasers, in which a specialized computer maps specific corrections for each individual eye.  In studies in which wavefront lasers were used, often referred to as custom LASIK, instead of the older technology of conventional LASIK, the visual results achieved with IntraLase are substantially better than those achieved with a microkeratome using the same technology.  The anecdotal information reported by Dr. Woodhams and Dr. Kameen, both of whom use wavefront LASIK almost exclusively, corroborate the results of such studies. 

IntraLase has been FDA approved since 2001 and has been used in the treatment of more than 250,000 eyes. Through the years the technology has been adjusted and doctors have honed their technique, and, in many instances, patients are reaping the benifits of LASIK without the blade. 

 

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