Changes in biomechanically corrected intraocular pressure and dynamic corneal response parameters before and after transepithelial photorefractive keratectomy and femtosecond laser-assisted laser in situ keratomileusis

Lee, Hun, Roberts, Cynthia J, Kim, Tae-im, Ambrosio, Renato Jr, Elsheikh, Ahmed ORCID: 0000-0001-7456-1749 and Kang, David Sung Yong (2017) Changes in biomechanically corrected intraocular pressure and dynamic corneal response parameters before and after transepithelial photorefractive keratectomy and femtosecond laser-assisted laser in situ keratomileusis. JOURNAL OF CATARACT AND REFRACTIVE SURGERY, 43 (12). pp. 1495-1503.

Text Paper on bIOP and DCR before-after surgery with Kang 2016 004.pdf - Author Accepted Manuscript Download (211kB)

Abstract

<h4>Purpose</h4>To evaluate the changes in biomechanically corrected intraocular pressure (IOP) and new dynamic corneal response parameters measured by a dynamic Scheimpflug analyzer before and after transepithelial photorefractive keratectomy (PRK) and femtosecond laser-assisted laser in situ keratomileusis (LASIK).<h4>Setting</h4>Yonsei University College of Medicine and Eyereum Eye Clinic, Seoul, South Korea.<h4>Design</h4>Retrospective case series.<h4>Methods</h4>Medical records of patients having transepithelial PRK or femtosecond-assisted LASIK were examined. The primary outcome variables were biomechanically corrected IOP and dynamic corneal response parameters, including deformation amplitude ratio 2.0 mm, stiffness parameter at first applanation, Ambrósio relational thickness through the horizontal meridian, and integrated inverse radius before the procedure and 6 months postoperatively.<h4>Results</h4>Of the 129 patients (129 eyes) in the study, 65 had transepithelial PRK and 64 had femtosecond-assisted LASIK. No significant differences in biomechanically corrected IOP were noted before and after surgery. The deformation amplitude ratio 2.0 mm and integrated inverse radius increased, whereas the stiffness parameter at first applanation and the Ambrósio relational thickness through the horizontal meridian decreased after surgery (P < .001). The changes in deformation amplitude ratio 2.0 mm and integrated inverse radius were smaller in transepithelial PRK than femtosecond-assisted LASIK (P < .001). Using analysis of covariance, with refractive error change or corneal thickness change as a covariate, the changes in deformation amplitude ratio 2.0 mm and integrated inverse radius were smaller in transepithelial PRK than femtosecond-assisted LASIK (P < .001).<h4>Conclusions</h4>The dynamic Scheimpflug analyzer showed stable biomechanically corrected IOP measurement before and after surgery. The changes in dynamic corneal response parameters were smaller with transepithelial PRK than with femtosecond-assisted LASIK, indicating less of a biomechanical effect with transepithelial PRK.

Item Type:	Article
Uncontrolled Keywords:	Cornea, Humans, Tonometry, Ocular, Keratomileusis, Laser In Situ, Postoperative Period, Retrospective Studies, Intraocular Pressure, Photorefractive Keratectomy
Depositing User:	Symplectic Admin
Date Deposited:	17 Jan 2018 14:13
Last Modified:	13 Feb 2024 15:54
DOI:	10.1016/j.jcrs.2017.08.019
Related URLs:	Author Publisher
URI:	https://livrepository.liverpool.ac.uk/id/eprint/3016007