Clinical Ophthalmology (Dec 2023)
Safety and Effectiveness of Smooth Incision Lenticular Keratomileusis (SILKTM) Using the ELITA(TM) Femtosecond Laser System for Correction of Myopic and Astigmatic Refractive Errors
Abstract
Mahipal S Sachdev,1 Rohit Shetty,2 Pooja Khamar,2 Raghav Malik,1 Brian L Schwam,3 Ying Wang,3 Hong Fu,3 Andrew P Voorhees,3 Michal Laron3 1Centre for Sight, New Delhi, India; 2Narayana Nethralaya Eye Hospital, Bangalore, India; 3Johnson and Johnson Surgical Vision, Inc, Milpitas, CA, USACorrespondence: Michal Laron, Johnson and Johnson Surgical Vision, Inc, 510 Cottonwood Drive, Milpitas, CA, 95035, USA, Tel +1 408 273 5802, Email [email protected]: To evaluate visual outcomes following the Smooth Incision Lenticular Keratomileusis (SILKTM) procedure for correction of myopic refractive errors with and without astigmatism, using the ELITATM Femtosecond Laser System.Patients and Methods: A prospective, multicenter, single-arm, open-label clinical study was conducted. Eighty-five myopic subjects (n = 170 eyes), aged 18 years or older, with manifest refractive spherical equivalent (MRSE) up to − 12.00 D and astigmatism up to − 6.00 D, were treated binocularly using the ELITA femtosecond laser and followed up for 6 months. Intended correction was emmetropia for all eyes. The primary outcome measures included post-operative uncorrected and corrected distance visual acuity (UDVA and CDVA). Secondary outcome measures included surgeon’s rating for ease of lenticule extraction, predictability, safety, and stability.Results: A total of 170 eyes of 85 patients underwent SILK. Preoperative mean MRSE was − 4.14 D ± 1.32 D (range − 1.38 D to − 8.88 D) and the mean cylinder was − 0.77 D ± 0.62 D. Intraoperative surgeon ease of lenticule dissection was rated as grade 0 or 1 in 85.3% of eyes (no/only mild dissection needed). UDVA at 1 day, 1 week, 1 month, and 6 months was 20/20 or better in 65.9%, 85.4%, 91.5%, and 96% of eyes, respectively. No eyes lost any lines of CDVA at 6 months compared to the preoperative. The postoperative MRSE was stable over time, ranging from − 0.34 D ± 0.24 D at 1 month to − 0.33 D ± 0.23 D at 6 months. MRSE predictability (± 0.50 D) was 93.5% (129/138) at 3 months and 91.1% (113/124) at 6 months. No serious adverse events were noted.Conclusion: The SILK procedure with the ELITA Femtosecond Laser System is safe and effective for the treatment of myopic refractive errors with and without astigmatism. Fast visual recovery was demonstrated, with stability achieved by 3 months.Keywords: smooth incision lenticular keratomileusis, SILK, laser-assisted lenticule extraction, corneal refractive surgery, myopia, keratorefractive lenticule extraction