Changes in Corneal Biomechanical Properties after Laser-Assisted in situ Keratomileusis and Photorefractive Keratectomy in Myopia.

Autor: Humayun S; Department of Eye, Armed Forces Institute of Ophthalmology, Rawalpindi, Pakistan., Bangash YW; Department of Eye, Armed Forces Institute of Ophthalmology, Rawalpindi, Pakistan., Ishaq M; Department of Eye, Mazhar Ishaq Centre of Ophthalmology, Rawalpindi, Pakistan., Yasmeen H; Department of Eye, Armed Forces Institute of Ophthalmology, Rawalpindi, Pakistan.
Jazyk: angličtina
Zdroj: Journal of the College of Physicians and Surgeons--Pakistan : JCPSP [J Coll Physicians Surg Pak] 2023 Sep; Vol. 33 (9), pp. 1023-1027.
DOI: 10.29271/jcpsp.2023.09.1023
Abstrakt: Objective: To compare changes in corneal biomechanical properties after laser-assisted in situ keratomileusis (LASIK) and photorefractive keratectomy (PRK) in low and moderate myopia by Ocular Response Analyzer.
Study Design: Quasi-experimental study. Place and Duration of the Study: Armed Forces Institute of Ophthalmology (AFIO), Rawalpindi, Pakistan, between September 2020 and April 2022.
Methodology: Myopic correction was done in forty-six eyes of twenty-three patients by PRK, and forty-seven eyes of twenty-four patients by LASIK. Corneal hysteresis (CH) and corneal resistance factor (CRF) were measured using Ocular Response Analyzer (ORA), pre-operatively, and then 1, 3, and 6 months, postoperatively. The relationship between the amount of myopia treated and biomechanical properties was also studied.
Results: CRF and CH were decreased significantly after LASIK and PRK. A significantly larger decrease in CRF was observed after LASIK as compared to PRK at 6 months (Mann-Whitney U test: CRF, p = 0.02); however, decrease in CH was not statistically significant between LASIK and PRK at 6 months period (Mann-Whitney U test: CH, p = 0.388). A significant correlation was observed between the changes in biomechanical properties and extent of myopic correction after LASIK and PRK.
Conclusion: Biomechanical strength of the cornea was significantly reduced by PRK and LASIK, which was also dependent on the spherical equivalent (SEQ) of myopic correction. A significantly larger change in CRF was observed after LASIK as compared to post PRK.
Key Words: Myopia, Laser in situ keratomileusis, Photorefractive keratectomy, Cornea, Biomechanics.
Databáze: MEDLINE