Advantages with SMILE

Small incision lenticule extraction (SMILE) may be more predictable and stable for correcting myopic astigmatism than LASIK, with similar visual outcomes, Varintorn Chuckpaiwong MD told the XXXIV Congress of the ESCRS in Copenhagen, Denmark. In a retrospective study involving 4,881 patients treated from July 2010 through to June 2016, mean cylinder fell from -1.00 ±0.75D for 8,406 eyes before surgery to -0.25 ±0.50D for 7,288 eyes one month after undergoing SMILE for compound myopic astigmatic correction at the TRSC International LASIK Center in Bangkok, Thailand. Mean cylinder outcomes for this group remained identical at all subsequent measurement points out to three years, including for 4,973 eyes at one year and 743 eyes at three years, reported Dr Chuckpaiwong, of Ramathibodi Hospital, Mahidol University, Bangkok, Thailand. For a much smaller group of eyes undergoing SMILE for simple myopic astigmatism correction, results were similar, though some fluctuation was observed, Dr Chuckpaiwong said. Mean cylinder went from -2.25 ±1.50D for 85 eyes before surgery to -0.25 ±0.50D for 78 eyes one month post-op, 0.00 ±0.50D for 65 eyes at six months, -0.25 ±0.75D for 44 eyes at one year, and -0.75 ±0.00D for two eyes at three years. Predictability was also excellent, Dr Chuckpaiwong said. At one year, cylinder was within 0.5D of intended for 88% and within 1.0D for 99% of the compound myopic astigmatism group, and 76% and 92% respectively for the simple myopic astigmatism group. These results are similar to or slightly better than SMILE and LASIK results in the literature, she added (Moshirtar M et al. J Cataract Refract Surg 2015; 41:652-665).

In comparison to LASIK, SMILE shows better efficacy and predictability and also long-term stability for correcting myopic astigmatism

As for safety, 13.71% lost one line of best corrected visual acuity at one month and 7.32% lost one line at one year, while 20.38% gained one or more lines at one month, and 35.37% gained one or more lines at one year in the compound myopic astigmatism group, Dr Chuckpaiwong said. These results also are similar to LASIK outcomes. In comparison to LASIK, SMILE shows better efficacy and predictability and also long-term stability for correcting myopic astigmatism, Dr Chuckpaiwong said. This may be because SMILE does away with the LASIK flap, which one study showed induces an average of 0.12D with-the-rule astigmatism (Huang D. J Refract Surg 2000;16:515-518). She plans further analysis of her study to improve SMILE astigmatism correction.   Varintorn Chuckpaiwong: iamjeabs@yahoo.com