Effect of flap homogeneity on higher-order aberrations induction after femtosecond LASIK for myopia. Issue 9 (September 2020)

• Record Type: Journal Article
• Authors: Parafita-Fernandez, Alberto; Gros-Otero, Juan; Villa-Collar, Cesar; García-González, Montserrat; Teus, Miguel
• Is Part Of: Journal of cataract and refractive surgery. Volume 46:Issue 9(2020)
• Page Start: 1278
• Page End: 1283
• Publication Date: 2020-09
• Subjects: 617.7
• DOI: 10.1097/j.jcrs.0000000000000255
• Languages: English
• ISSNs: 0886-3350

Abstract

Abstract : Different femtosecond lasers induce irregularities in flap thickness correlated with differences in visual quality; even using the same excimer laser, the intraflap thickness heterogeneity is correlated with visual results. Abstract : Purpose: To assess the relevance of the homogeneity of femtosecond laser flap thickness regarding induction of higher-order aberrations (HOAs). Setting: Clínica Rementería & Clínica Novovisión, Madrid, Spain. Design: Prospective observational study. Methods: Two hundred thirty-one patients underwent in situ keratomileusis using 5 different femtosecond lasers. The flap thicknesses were measured using anterior segment optical coherence tomography 3 months postoperatively. The same masked observer measured 6 symmetrical points nasally and temporally 1.0 mm, 2.0 mm, and 3.0 mm from the center of the flap in each case. HOAs induced in the cornea were measured using tomography. Results: Positive and significant correlations were found between HOA induction and the flap thickness heterogeneity 3.0 mm from the center of the flap. Pearson correlation coefficients for the induction of HOAs were third-order 0.17112 ( P = .0224), fourth-order 0.22474 ( P = .0026), fifth-order 0.16449 ( P = .0282), coma-like 0.17370 ( P = .0204), and total HOAs 0.18182 ( P = .0151). Conclusions: The amount of flap-thickness heterogeneity at 3.0 mm from the center of the flap created using femtosecond lasers was correlated with the magnitude of the HOAs induced.