Eyeworld

Reporting from the XXXV Congress of the ESCRS, October 7–11, Lisbon, Portugal EW MEETING REPORTER 90 Dr. Dupps discussed research, based on a model of patient-specific geometry, that showed how stress in LASIK was carried in the residual stromal bed, compared to SMILE where most of the stress remained at the cap. Dr. Dupps also described a patient who was told he was not a good candidate for any refractive procedure as there was evidence of early keratoconus. This patient went elsewhere and received SMILE. He developed ectasia. Dr. Dupps and his team simulated the SMILE procedure on this patient's eye and found his risk for ectasia was very high, but the additional risk added by SMILE was low. The take-home point of this is that even though SMILE seems to have a lower biomechan- ical impact, it doesn't mitigate the preoperative risk in the first place. Overall, Dr. Dupps said that SMILE does present a stability ad- vantage compared to LASIK or fem- tosecond lamellar extraction (FLEx) in normal corneas, but perhaps not in those with occult anterior weak- ness. He said clinical measures for measuring depth dependent prop- erty gradients are needed to define risk and optimal choice for refractive surgery. As for SMILE complications, Catherine Albou-Ganem, MD, Paris, France, said most are related can outperform SMILE in some of these ways. In a single paired eye study where one eye received topog- raphy-guided femtosecond LASIK and the other eye SMILE, efficacy was 86.4% for LASIK and 58.2% for SMILE; predictability within 0.5 D was 95.5% for LASIK and 77.3% for SMILE. Dr. Hjortdal suggested that individualized modifications of lent- icule cutting could improve SMILE. Quality of vision with SMILE, which is impacted by interface quality, functional optical zone size, aberration, ocular surface recovery, and psychometric assessment, was discussed by Jodhbir Mehta, MD, Singapore. In terms of patient-re- lated responses, Dr. Mehta said SMILE has been shown equivalent to LASIK, but it is superior to LASIK in having a larger functional optical zone, reduced higher order aber- rations, and faster ocular surface recovery. One of the most important questions we've heard with SMILE, William Dupps, MD, PhD, Cleve- land, said, is the effect on structural stability and risk of ectasia. It's accepted, Dr. Dupps said, that the interweaving collagen fibers of the anterior cornea confers additional strength; these fibers become more stacked and weaker as you go deeper. This is where SMILE might be advantageous, in that it leaves these stronger anterior fibers preserved. motion. IRIS (Pixium Vision, Paris, France) works via a similar concept, but its receiver is on an intraocular lens and its epiretinal implant has 1,550 electrodes. Subepiretinal implantation of a chip with 1,600 electrodes (Retina Implant Alpha AMS, Retina Implant, Reutlingen, Germany) is more tech- nically difficult as a procedure, but Dr. Gabel said research has shown patients with this device have been able to detect a number of different objects and perform daily living activities after 4 weeks of training. "To smile or cry": Symposium covers lenticule extraction It was standing room only in the "Intrastromal lenticule extraction: To smile or cry?" symposium, where experts presented various aspects of small incision lenticule extraction (SMILE). Leonardo Mastropasqua, MD, Chieti, Italy, compared SMILE and LASIK from a recovery, complica- tion, and biomechanical standpoint. Research shows, for example, that keratocyte damage and interface changes are less pronounced in ReLEx SMILE (Carl Zeiss Meditec, Jena, Germany) compared to fem- tosecond LASIK, which Dr. Mastro- pasqua said could represent a cellu- lar basis for better wound healing. In vivo findings also show less denervation and faster nerve regeneration with SMILE compared to the flap creation in LASIK, which Dr. Mastropasqua said could be associated with better preservation of the corneal neural architecture and could translate to fewer dry eye symptoms. The SMILE procedure offers the opportunity to preserve useful lent- icules that are removed during the procedure for implantation in treat- ing ametropia and corneal diseases, such as keratoconus. Jesper Hjortdal, MD, Aarhus, Denmark, presented published data about the efficacy and predictability of SMILE compared to other laser surgery for myopia. On the whole, SMILE has similar efficacy, predict- ability, stability, and safety com- pared to LASIK and PRK procedures, but, Dr. Hjortdal said, advanced individually guided laser treatments November 2017 continued on page 92 View videos from ESCRS 2017: EWrePlay.org Oliver Findl, MD, discusses increased accuracy in IOL calculations achievable by incorporating posterior corneal measurements.

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