Comparison of corneal hysteresis and corneal resistance factor after small incision lenticule extraction and femtosecond laser-assisted LASIK: A prospective fellow eye study

• Published in: Contact lens & anterior eye Vol. 37; no. 2; pp. 77 - 80
• Main Authors: Agca, Alper, Ozgurhan, Engin Bilge, Demirok, Ahmet, Bozkurt, Ercument, Celik, Ugur, Ozkaya, Abdullah, Cankaya, Ilker, Yilmaz, Omer Faruk
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.04.2014
• Subjects: Adult; Biomechanics; Cornea - physiopathology; Cornea - surgery; Corneal hysteresis; Corneal resistance factor; Corneal Topography; Elasticity; Female; Hardness; Humans; Keratomileusis, Laser In Situ - methods; LASIK; Male; Minimally Invasive Surgical Procedures - methods; Myopia - diagnosis; Myopia - physiopathology; Myopia - surgery; Ophthalmology; Prospective Studies; Refractive Surgical Procedures - methods; Small incision lenticule extraction; SMILE; Treatment Outcome; Viscosity; Biomechanics; Corneal resistance factor; SMILE; LASIK; Small incision lenticule extraction; Corneal hysteresis
• ISSN: 1367-0484; 1476-5411
• DOI: 10.1016/j.clae.2013.05.003

Abstract Purpose To compare corneal hysteresis (CH) and corneal resistance factor (CRF) between eyes treated with small incision lenticule extraction (SMILE) and femtosecond laser-assisted laser in situ keratomileusis (femto-LASIK). Setting Beyoğlu Eye Training and Research Hospital. Design Prospective comparative case series. Methods Sixty eyes from 30 patients with bilateral myopia or myopic astigmatism were studied. Inclusion criteria were spherical equivalent of subjective manifest refraction (SE) <10 diopters (D) and a difference ≤0.50 D between the SEs of both eyes. One eye of each patient was treated with SMILE, and the fellow eye underwent femto-LASIK. Randomization was performed using a sealed envelope system. The main outcome measures were CH and CRF measured preoperatively and postoperatively (1 and 6 months). Results Preoperative SE was similar in both groups ( p = 0.852). CH and CRF values were reduced postoperatively in both groups compared to their corresponding preoperative values ( p < 0.001). At the 6-month follow-up visit, the mean CH values in the SMILE and femto-LASIK groups were 8.95 ± 1.47 and 9.02 ± 1.27, respectively ( p = 0.852), and the mean CRF values were 7.77 ± 1.37 and 8.07 ± 1.26, respectively ( p = 0.380). Conclusion CH and CRF decreased after SMILE. There were no differences between SMILE and femto-LASIK treatments in postoperative CH or CRF values.