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Up Front | May 2005

10 Questions on the Future of LASIK

10 Questions on the Future of LASIK We asked Perry S. Binder, MS, MD; Stephen G. Slade, MD, FACS; and John A. Vukich, MD, to consider the changing landscape of LASIK over the next several years.

1. Where do you see refractive laser surgery in 2 years?

Perry S. Binder, MS, MD: I predict that, in 2 years, PRK and LASIK will be used for treating moderate refractive errors from +3.00 to -8.00D, depending on individual corneal thickness, mesopic pupil diameter, and the flap-creation system used. Mitomycin C will be used for complicated cases in low doses (eg, 0.002%). The femtosecond laser will become the standard of care for flap creation. Laser software will continue to improve the predictability of systems' outcomes. We will determine the best refractive errors for phakic IOLs, and, with experience, the refractive indications will translate into the indications for LASIK and PRK. We will not have an established procedure for presbyopia. The capabilities of accommodative IOLs will be defined. Contact-lens technology will improve to compete with other refractive modalities. Wavefront-corrected spectacles and contact lenses will be in the clinical realm. Some keratoconic eyes will undergo PRK and the implantation of intracorneal ring segments.

Stephen G. Slade, MD, FACS: I do not see any profound changes taking place in laser refractive surgery in the next 2 years. I think the specialty is currently in a refinement phase as opposed to an innovation phase. I expect providers to fine-tune the percentage of LASIK versus PRK procedures that they perform, and they may increase their amount of PRK procedures over the next couple of years. In addition, practitioners may become increasingly conservative about which patients they treat with LASIK and PRK, considering the current medicolegal atmosphere. One positive result of those concerns may be that surgeons will become more diligent about preoperative documentation, testing, and patient selection.

John A. Vukich, MD: I predict that the number of laser refractive procedures performed on an annual basis will steadily increase over the next 2 years. The upper limit of laser correction for myopic eyes with adequate corneal thickness will be -10.00D. Continued refinement of the delivery of laser correction will make therapeutic treatments more predictable. I think the most important trend will be the emergence of intraocular surgery as an accepted alternative to corneal reshaping. Early experience with phakic IOLs will be positive, and more practices will offer intraocular refractive surgery as an option.

2. Where do you see refractive laser surgery in 5 years?

Perry S. Binder, MS, MD: Depending on the factor(s) that define the risk(s) for ectasia, LASIK will still be the primary refractive procedure, and surface ablation will be the second most common modality for treating moderate refractive errors. New excimer lasers will be faster and have automatic tracking in the x, y, and z planes as well as automatic cyclotorsional registration. Topography-driven customized corneal ablations associated with wavefront analysis will be commonplace. Faster femtosecond technology will create flaps safely in 20 or fewer seconds. The best surface-ablation technique will be determined (PRK, LASEK, or Epi-LASIK). Phakic IOLs and insertion techniques will improve, and the lenses' indications will expand. New presbyopic procedures that act directly on the crystalline lens will be developed. Wavefront-corrected IOLs, toric IOLs, wavefront-corrected spectacles, and improved accommodative/diffractive IOLs will be commonplace. Contact-lens technology will improve, but its market will shrink as refractive surgery increases its penetration. The long-term results of conductive keratoplasty will be determined, and the procedure will be replaced.

Stephen G. Slade, MD, FACS: Within 5 years, I think there will be some significant shifts in refractive surgery. It could have some new technologies. Also, the specialty may be significantly affected by lens-based refractive surgery, particularly now that the FDA has approved the Verisye IOL (Advanced Medical Optics, Inc., Santa Ana, CA) and if it approves the ICL (Staar Surgical Company, Monrovia, CA). These IOLs will encourage surgeons to reevaluate which patients they treat with lens-based procedures and which they treat with laser-based surgery. Also, in 5 years, I anticipate our having new laser platforms that improve upon today's systems. For example, they may be capable of firing 500 to 1,000 shots per second, provide real-time feedback during the ablation, and combine topographical and wavefront capabilities. I also predict that wavefront-guided software will be significantly better in 5 years. I think the laser platforms will really come into their own.

John A. Vukich, MD: The 5-year outlook is not dramatically different than the 2-year trend for refractive surgery. The wild card will be the availability of true accommodative IOLs, which should be through the FDA process by this time. If we can reliably achieve 4.00D of peak and 2.00D of sustained accommodation with an IOL, it will completely reshape the way in which we think about refractive surgery.

3. Will lamellar or surface ablation be the preferred method by which most treatments are completed?

Perry S. Binder, MS, MD: The push for surface treatment will be solely influenced by the risk(s) of ectasia. If surgeons are able to identify the eyes that are at risk, they will continue to apply LASIK surgery, because both surgeons and patients prefer its benefits.

Stephen G. Slade, MD, FACS: I think lamellar ablations will remain the preferred treatment method. Once two technologies approach a certain proximity in their results, the issue largely becomes one of patients' preference. Although PRK has always delivered results comparable to LASIK, surgeons bought microkeratomes because patients wanted LASIK, and I think most patients view LASIK as the most convenient, accessible option. Ophthalmologists sometimes focus too much on lines of vision and visual acuity results, but patients consider other factors when choosing a refractive treatment. I doubt that physicians will replace LASIK with surface ablation, partly because of the amount of pre- and postoperative medications that surface ablation requires (as many as 13 oral and topical medications with some regimens). Furthermore, I expect that, after the excitement about Epi-LASIK has worn off, the modality will reveal some complications. Surface ablation is a great tool; I use it in 5% to 8% of my patients and am happy to have it as a surgical option, but I do not see it becoming the dominant technique.

John A. Vukich, MD: Lamellar ablation will remain the preferred method. Comfort and speed of recovery will remain the primary drivers of lamellar surgery. Surface ablation with either PRK or Epi-LASIK will level off at approximately 10% of all cases, primarily in patients with marginal pachymetry. The high hopes that Epi-LASIK will provide a safer alternative to lamellar surgery will be tempered by the former's delayed healing times compared with PRK and clinical outcomes that demonstrate marginal if any advantage.

4. If lamellar surgery wins out, will it favor laser flap creation or mechanical means?

Perry S. Binder, MS, MD: It is clear, in 2005, that laser flap creation is safer and more predictable than mechanically created flaps. Also, early data support better refractive outcomes with laser flap creation. Improvements in laser technology will make this difference more substantial.

Stephen G. Slade, MD, FACS: I think surgeons will continue to use both. The percentage of laser keratomes has increased, but there are the factors of time and cost to consider. Certain patients may best be served by a particular type of keratome, such as metal keratomes for previous RK patients or laser keratomes for patients with loose epithelia. Patient education and perception also may play important roles in the surgeon's choice. Although patients like the idea of all-laser procedures, many are completely unaware of the step of creating a flap in LASIK.

John A. Vukich, MD: Mechanical flap creation will remain the most common method. The increased cost and the minimal impact on clinical outcomes will limit the widespread use of flap creation with a laser. Most patients are more interested in how well they can expect to see after surgery as opposed to how the individual steps of the surgery are carried out. As long as the safety profile and outcomes with mechanical keratomes remain similar to those of laser flap creation, there will be a limited incentive for most surgeons to change. The downside to mechanical microkeratomes is that they are very one-dimensional in their versatility. Laser flap creation may gain market share if a novel application is devised for which the laser is better suited.

5. Will wavefront “optimized” or “customized” rule the day?

Perry S. Binder, MS, MD: We clearly need better ablation software and lasers that are capable of delivering the energy where it is needed. Both will improve. We will also develop a combined means of assessing topographic and wavefront errors to improve outcomes. Perhaps such a technology will provide an as yet undiscovered means of vision assessment.

Stephen G. Slade, MD, FACS: Customized will prevail, because optimized ablations are not the same thing. Customized ablations deliver a different treatment to each patient, whereas optimized ablations give the same ablation to every patient with a given refraction. Granted, a wavefront-optimized ablation is contoured to the cornea compared with the standard algorithms that are commonly used, and I do think that feature offers a benefit. However, wavefront-customized laser platforms are all capable of being programmed to deliver extra ablation shots in the periphery, and they have the added benefit of being able to treat higher-order aberrations. I think that the optimized algorithm could be part of an improvement in customized platforms. Furthermore, I think patients will become aware of less-than-open marketing about the differences between optimized and customized.


ohn A. Vukich, MD: Wavefront customized ablation will be the standard of care. Improvements in capture, interpretation, registration, and delivery will further improve individual wavefront-driven corrections. The limitations of wavefront optimization compared with truly customized treatments will become more apparent as we continue to refine the delivery systems.

6. Will cyclotorsional tracking be required?

Perry S. Binder, MS, MD: Yes, to maximize outcomes for those eyes that rotate between the sitting and supine positions. Today, we accept 5º to 10º of rotation; tomorrow, we will accept none.

Stephen G. Slade, MD, FACS: I do not know the answer to that yet. Some articles say that a few patients really do experience cyclotorsion, and others state that tracking is unnecessary. My staff and I mark every eye, and some eyes do cyclotort. My best guess is that cyclotorsional tracking will be required. As the technology improves and tracking becomes relatively easy to incorporate, I think it will be done.

John A. Vukich, MD: Cyclotorsional registration and tracking will be an important step in improving the accuracy of laser delivery. The current method of manually marking the sclera has a too large a margin of error. Automating this component of the delivery process will be a significant improvement.

7. Will a solid-state laser be available for ablating tissue for refractive purposes?

Perry S. Binder, MS, MD: My practice had the Novatec laser (Novatec Laser Systems Inc., San Diego, CA), which worked nicely. A solid-state laser that was less costly both up front and to operate would supplant the argon-fluoride excimer lasers.

Stephen G. Slade, MD, FACS: It is possible that a solid-state laser could be used for refractive ablations. The gas tube, however, is not the problem with current excimer lasers. Their maintenance involves the lenses, mirrors, and all the parts through which the corrosive beam passes. Rarely does the gas head of a laser burn out. Solid-state lasers have two cathodes that must be adjusted if a spark jumps between them. I do not see solid state as a huge improvement for excimer lasers anytime soon, or it would have been done by now. They are approximately 90% as service-intensive as a gas laser.

John A. Vukich, MD: Any new laser entry into the refractive market will have to compete with excimer lasers that have undergone several generations of refinement. The results from the current lasers are quite good, and this creates a significant barrier to entry for new technology. Unless solid-state lasers can demonstrate a real clinical advantage or a reduced acquisition cost, it seems unlikely they will succeed commercially.

8. How will phakic IOLs impact laser vision correction?

Perry S. Binder, MS, MD: As we develop safer lens technology and improve its predictability, phakic IOLs will expand in refractive indications for myopia and hyperopia. Ultimately, a refractive error range will be determined to have similar outcomes with both technologies, so the surgeon and patient will have to weigh these factors. My guess is that laser surgery will be used for treatments of up to -6.00D and hyperopic surgery for up to +3.00D, depending on the patient's preoperative corneal power. IOLs will treat all other errors.

Stephen G. Slade, MD, FACS: I think phakic IOLs and laser vision correction will help grow each other. Phakic IOLs may take a percentage of the market from laser vision correction, but overall they will drive the entire market, because people who are not candidates for phakic IOLs will turn to LASIK, and those who should not have LASIK will receive phakic IOLs (no more -12.00D ablations). Plus, many who receive phakic IOLs will need laser touch-ups for problems such as astigmatism or sphere. This relationship will benefit manufacturers, who will receive the same procedural fees for retreatments as for regular procedures.

John A. Vukich, MD: The early use of phakic IOLs will be primarily in those individuals who would otherwise be unable to have laser vision correction. Strong word-of-mouth recommendations from early satisfied phakic IOL patients will drive an increase in patient as well as physician acceptance of these lenses. Phakic IOLs will ultimately represent approximately 10% of all refractive procedures.

9. Will presbyopic laser vision correction be a true remedy?

Perry S. Binder, MS, MD: Probably not. It is a temporary fix. We need to attack the real problem of the lens' aging. Lens replacement with synthetics theoretically has the best chance of reversing presbyopia.

Stephen G. Slade, MD: Presbyopic laser vision correction, which ablates a multifocal correction on the cornea, will truly benefit certain patients. Others, as we know from multifocal contact lenses and IOLs, simply will not tolerate the loss of contrast sensitivity, multiple images, etc. Patients should try the treatment first with contact lenses, and then they can undergo the permanent laser treatment if they choose. It requires the right patient.

John A. Vukich, MD: True presbyopic correction will require a truly accommodative IOL. Multifocal laser correction will provide adequate near and distance vision for many patients and will gain acceptance as an alternative to monovision. The use of this technique will be limited primarily to hyperopic patients.

10. If higher orders are corrected, how long do you think the effects of the treatment will last?

Perry S. Binder, MS, MD: We have to assume that the measured higher-order aberrations are mostly in the cornea. As the lens' higher-order aberrations increase, we can be sure that the benefits of corneal surgery will lessen. We need to determine the effect of lens removal on outcomes following wavefront-corrected corneal surgery.

Stephen G. Slade, MD, FACS: I do not think that higher-order corrections will regress. These treatments do not dramatically change the slope of the cornea so that it epithelializes inward. Time will prove their efficacy, however.

John A. Vukich, MD: Correcting the visual system of an eye to its fullest potential will always be desirable. The fact that higher-order aberrations show minor changes over the lifetime of a patient does not diminish the benefit of wavefront-guided correction. The best we can ever hope to do is reset the clock to zero. n

Perry S. Binder, MS, MD, is Associate Clinical Professor, nonsalaried, for the Department of Ophthalmology, University of California, San Diego, and practices at the Gordon Binder Vision Institute in San Diego. He is a paid consultant for Intralase Corp. but states that he holds no financial interest in any product mentioned herein. Dr. Binder may be reached at (858) 455-6800; garrett23@aol.com.

Stephen G. Slade, MD, FACS, is in private practice in Houston. He is a consultant for Staar Surgical Company and Intralase Corp. but states that he holds no financial interest in any product mentioned herein. Dr. Slade may be reached at (713) 626-5544; sgs@visiontexas.com.

John A. Vukich, MD, is Assistant Clinical Professor at the University of Wisconsin, Madison. He is a consultant to Staar Surgical Company but states that he holds no financial interest in any product mentioned herein. Dr. Vukich may be reached at (608) 282-2002; javukich@facstaff.wisc.edu.

For a downloadable pdf of this article, including Tables and Figures, click here.
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