Improvements in technology expand refractive surgery options
CHICAGO — Contemporary laser refractive surgery results are good, but advancements in technologies and techniques could further improve outcomes, according to a speaker here.
Over the past 20 years, excimer lasers have become faster, ablation profiles have improved, nomograms have been refined, and more variables can be controlled, Jodhbir S. Mehta, MBBS, PhD, said at the Refractive Surgery Subspecialty Day preceding the American Academy of Ophthalmology annual meeting.
“For PRK and LASIK, we have almost two decades of evaluation for our patients, so we do have a long-term record to look at. There has been a gradual shift towards a majority of flaps being created with a femtosecond laser, and now with SMILE coming around in the last decade, we’ve seen almost 1.6 million procedures being performed with this new refractive laser procedure,” he said.
Visual acuity outcome results for LASIK and small incision lenticule extraction (SMILE) are comparable, but in the last few years it has become obvious that centration is important for SMILE outcomes, he said.
Trackers control the centration during LASIK, but the surgeon controls centration during SMILE, which can result in variability of outcomes, he said.
Better centration reduces total higher order aberrations, coma and total displacement associated with induced vertical coma and induced spherical aberration, while lower energy used in SMILE seems to result in better visual outcomes and earlier rehabilitation, he said.
All three procedures – PRK, LASIK and SMILE -- can result in better visual outcomes, so the patient is the determining factor for which type of procedure the surgeon feels is best. For example, if a patient is nervous or difficult to examine with a slit lamp, SMILE would not be an appropriate procedure, he said.
“Of course, patients who do sports or are worried about flap creation, we’d look to a flapless procedure. Also, when you’re looking at moderate to higher degrees of myopia there are distinct advantages to doing a lenticule procedure compared to any of the excimer-based procedures. We’re driving our outcomes now related to our patients, we’re not trying to fit our patients into what we’re able to do,” he said. – by Robert Linnehan
Reference: Mehta JS. Advances in corneal surgery for myopia: LASIK vs. SMILE vs. PRK. Presented at: AAO Subspecialty Day; Oct. 26-27, 2018; Chicago.
Disclosure: Mehta reports receiving lecture fees and grant support from Carl Zeiss Meditec.