Faculty Collaboration Database

Conventional Versus Inverted Side-cut Flaps for Femtosecond Laser-Assisted LASIK: Laboratory and Clinical Evaluation. J Refract Surg 2017 Feb 01;33(2):96-103

Date

02/14/2017

Pubmed ID

28192588

DOI

10.3928/1081597X-20161102-02

Scopus ID

2-s2.0-85013392613 (requires institutional sign-in at Scopus site)   7 Citations

Abstract

PURPOSE: To study the differences in early corneal cellular events and biomechanical properties after femtosecond laser-assisted LASIK performed using conventional or inverted side-cut angles.

METHODS: In the laboratory study, left eyes of 24 rabbits underwent LASIK flap creation with a 70° or 115° side-cut. The contralateral eyes served as controls. The corneas were harvested 24 hours postoperatively. In the clinical study, 2 eyes of each patient (n = 29) were randomized to corneal flap creation with 70° or 115° side-cut angles during LASIK. The Ocular Response Analyzer (ORA; Reichert Ophthalmic Instruments, Depew, NY) was used to assess biomechanical properties of the cornea.

RESULTS: In rabbit eyes, epithelial ingrowth was observed more frequently in flaps with 70° side cuts compared to flaps with 115° side-cuts. Corneas with 70° side-cuts showed significantly increased apoptotic cells compared to 115° side-cuts in the central (P = .001) and peripheral (P = .004) regions. Fifty-eight eyes of 29 patients were included in the clinical study. An overall reduction in Goldmann-correlated intraocular pressure, corneal-compensated intraocular pressure, corneal resistance factor, corneal hysteresis measurements, p1 area, p2 area, and p1 area 1 and p2 area 1 was noted 37 ± 2 months after surgery (P < .001). No significant difference was observed in the change of any of these parameters between both groups (P ≥ .146).

CONCLUSIONS: Significant differences in wound healing were observed in rabbit corneas that underwent LASIK with conventional or inverted side-cuts. Variation in flap side-cut angles did not alter the long-term biomechanical properties measured with the ORA in patients after LASIK. [J Refract Surg. 2017;33(2):96-103.].

Author List

Jhanji V, Chan TC, Li WY, Lim RR, Yu MC, Law K, Yi P, Yip YW, Wang Y, Ng TK, Chaurasia SS, Mohan RR

Author

Shyam S. Chaurasia PhD Associate Professor in the Ophthalmology and Visual Sciences department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Adult
Animals
Apoptosis
Biomechanical Phenomena
CD11b Antigen
Corneal Keratocytes
Corneal Stroma
Female
Fluorescent Antibody Technique, Indirect
Humans
In Situ Nick-End Labeling
Intraocular Pressure
Keratomileusis, Laser In Situ
Ki-67 Antigen
Lasers, Excimer
Male
Middle Aged
Myopia
Rabbits
Surgical Flaps
Visual Acuity
Wound Healing
Young Adult