Corneal biomechanical properties after laser-assisted in situ keratomileusis and small-incision lenticule extraction in myopic eyes
Purpose The aim of this study was to compare the differences in corneal biomechanical changes after laser-assisted in situ keratomileusis (LASIK) and femtosecond laser small-incision lenticule extraction (SMILE) using the corneal visualization Scheimpflug technology (Corvis ST). Patients and methods...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Wolters Kluwer Medknow Publications
2020-01-01
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| Series: | Delta Journal of Ophthalmology |
| Subjects: | |
| Online Access: | http://www.djo.eg.net/article.asp?issn=1110-9173;year=2020;volume=21;issue=3;spage=146;epage=152;aulast=ElShourbagy |
| Summary: | Purpose The aim of this study was to compare the differences in corneal biomechanical changes after laser-assisted in situ keratomileusis (LASIK) and femtosecond laser small-incision lenticule extraction (SMILE) using the corneal visualization Scheimpflug technology (Corvis ST).
Patients and methods This is a prospective study that included two groups of myopic patients. Group 1 included 20 eyes that underwent LASIK surgery, and group 2 included 20 eyes that underwent SMILE surgery. The corneal biomechanical properties were assessed preoperatively and three months postoperatively using the Corvis ST in both groups. The main evaluated parameters included the first and second applanation (A1 and A2) time, absolute velocity and length, highest concavity (HC) time and radius, peak (P) distance, HC deflection amplitude, deformation amplitude, and Corvis biomechanical index.
Results There was no significant difference between the two groups regarding all preoperative biomechanical parameters measured by Corvis ST. At the third postoperative month, there was no significant difference between the two groups regarding A1 length or absolute velocity, whereas A1 time, A2 time, A2 length, absolute A2 velocity, and HC time were significantly lower among patients in the LASIK group than patients in the SMILE group. On the contrary, HC radius, P distance, HC deflection amplitude, deformation amplitude, and Corvis biomechanical index were significantly higher among patients in the LASIK group than patients in the SMILE group.
Conclusion SMILE and LASIK procedures substantially alter the corneal biomechanical properties measured by the Corvis ST. The LASIK procedure seemed to result in less tensile strength and more compliant cornea when compared with the SMILE procedure in myopic corrections. This denotes greater reduction in biomechanical stability in the LASIK procedure than in SMILE. |
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| ISSN: | 1110-9173 2090-4835 |