In all fields of medicine, potential technology change is variably visible on the horizon. Acceptance tends to come in waves that may be very small and fleeting or very large and enduring. Eventually, new technology does supplant the old; how this occurs is a fascinating process. Examples in ophthalmology of very small and fleeting waves of change would be epikeratophakia and hexagonal keratotomy. Clinical study results were either flawed or just not convincing enough for these procedures to persist as part of current care. A larger and more prolonged wave would be radial keratotomy, which has largely passed once all the complications became well known and better technology (excimer laser corneal refractive surgery) became widely available. Many other examples could be cited.

A tsunami that remains with us is phacoemulsification (phaco), which has maintained overwhelming predominant status for cataract surgery, at least in the developed world, for more than 20 years. While the battle for predominance with intracapsular cataract extraction with or without intraocular lenses (IOLs) may seem obvious from our historical vantage point, such was not the case when the new technology was first introduced. Phaco was dangerous with brunescent cataracts, and the complications for the early adopters were often viewed as unacceptable. So what happened? Technology evolved and by now, in a step-by-step fashion, standard features improved the user friendliness and range of cases that could be safely completed, such that about 20 years after introduction the tipping point occurred.

Principles we can learn from this process include:

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  New technology is compared to well-evolved technology, an often inherently unfair comparison, as advances with new technology are often not considered as part of the process. If the phaco machine I used for my first case in 1976 had been the same equipment I used 20 years later, the transition to phaco would never have occurred!

  
  
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  New technology does introduce new complications. As part of the acceptance process, they need to be recognized, categorized, and weighted for incidence and importance. No one had heard of wound burn or postocclusion surge-related problems until phaco came along; however, we learned how to deal with them.

So today’s new kid on the block is femtosecond laser–assisted cataract surgery (FLACS). For a few years it has been in common use, and we have adamant supporters and those who see it as only a small niche player or as really not adding anything to phaco alone. This is not all that dissimilar to where phaco was 5 years after introduction, except that we probably have more supporters of FLACS today than phaco did in the early 1970s. So what do the clinical studies tell us to date about FLACS, and how might they help us peer into the future to see how big and prolonged this FLACS wave might be in the cataract field?

First of all, true to form, FLACS has presented with a few unique complications related to system failure and suction loss. The system potentially can damage the cornea, iris, and posterior capsule, although the number of such cases is so rare that they are largely anecdotal. Also, the technology is progressing in ease of use and treatment rapidity. One obvious example is anterior capsular tags. Early adopters often had anterior capsular edge tears that could wrap around with loss of the nucleus into the vitreous. Like phaco, early comparisons were unfavorable. We also had clear evidence that the capsulotomy edge was irregular and more likely to tear than after a manual capsulorrhexis. Was this the end of the story? Hardly. One paper did not show differences when FLACS was compared with phaco, or maybe even showed an advantage in tough cases (intumescent cataract and dislocated lenses). Furthermore, another study did not show a difference between manual capsulorrhexis and FLACS in in vitro tear resistance. Another study documented continued anterior capsule problems, although most studies show that this is becoming less of a problem over time. Other unique concerns are the appearance due to subconjunctival hemorrhages, induced pupillary miosis, and possibly more inflammation with induced cystoid macular edema. However, others do not document this.

While most accept that, compared to phaco, FLACS is probably not inferior when it comes to complications, a more common comment is that it adds little to nothing in the majority of cases, with the price of more time expended and much higher cost. The counter-argument is that FLACS has real advantages, roughly summarized as more precise size, regularity, and centration of the capsular opening; more precise corneal entry incisions; and more efficient ultrasound use, with possible decrease in complications in difficult cases.

A femtosecond-generated anterior capsulotomy is a thing of perfection by all previous standards. No one argues with this. The counter-claim is, quite simply, so what? While some studies suggested that this perfection improved refractive stability, others have not supported this, and no study suggests any major differences. Furthermore, a future technology appears to enhance anterior capsulotomy tear-out strength and may have similar accuracy. Still, I can see that with IOLs where capsulotomy accuracy is important, as was the case for dual-optic accommodative IOLs, this could change in the future. The future may change this standoff, as may newer technology, although this advantage may be in just a few cases.

FLACS can precut the nucleus in ways that clearly can decrease the amount of ultrasound energy needed for nucleus removal, especially in the harder end of the spectrum; this is amply verified. Again, the counter-argument is, so what? For the vast majority of cataracts, the argument goes, the difference is clinically unimportant. Even in brunescent cataracts, where clear advantage may be important based on meaningful visual outcomes, no study has documented that FLACS decreased complications in brunescent cataracts. So while FLACS technology may be important for some very difficult cases or in leveling the playing field for those who have less experience with more brunescent cataracts, many see this nucleus removal efficiency advantage as clinically unimportant except, again, maybe for a small number of cases.

With corneal incisions, including astigmatic keratotomy, femtosecond laser accuracy would seem an advantage, but no clinical paper I could find documents this. What some talk about is that the more central position of the incisions makes subincisional work difficult, and opening these incisions can take longer than making new ones. Many surgeons who regularly perform FLACS have personally admitted to me that they make their own incisions. This is not a scientific poll, but it raises the issue that incision creation may not be an advantage, or at least the jury remains out.

So we have FLACS, this new technology that has shown steady improvement and that many support. Yet others feel its advantages are either clinically unimportant or lack convincing clinical studies to support uniform utilization in the face of increased expense and time. While this wave is far from peaking, it would seem that supporters of FLACS are remiss in not providing more robust comparative studies, especially looking at any complication differences in the very difficult cataract categories. Although the jury may be out, I think many cataract surgeons are underwhelmed with FLACS supplanting phaco alone as today’s dominant cataract removal procedure. That said, future studies and/or technology advancement may change this view.