Purpose: To assess the compensation of total ocular and corneal wavefront aberrations after conventional myopic LASIK.
Methods: This study comprised 57 eyes of 57 patients. Total and corneal aberrations were measured preoperatively and 3 months postoperatively using the OPD-Scan (NIDEK Co Ltd) aberrometer. Total and corneal aberrations root-mean-square (RMS) was calculated out to the 6th Zernike order for a 6.0-mm pupil diameter. The percentage increase postoperatively was defined by the ratio of RMS pre- and postoperatively for each corneal and total eye group. The compensation between corneal and internal aberrations for a given aberration group was defined as: (corneal aberration group RMS - total eye aberration group RMS)/corneal aberration group RMS.
Results: Postoperatively, higher order aberrations increased by a factor of 1.77+/-1.26 (total) and 2.47+/-2.25 (corneal) (P<.05). Coma aberration increased by a factor of 2.43+/-2.61 (total) and 2.56+/-2.66 (corneal). Spherical aberration increased by a factor of 1.46+/-1.83 (total) and 2.64+/-2.24 (corneal). The values of the ratio of compensation did not change significantly before and after LASIK for individual aberrations (P>.05).
Conclusions: Although myopic LASIK induced significant corneal aberrations, the level of partial compensation of corneal aberrations by internal structures remained unchanged. These results suggest that the previously described emmetropization that is effective during development may also be effective with acquired variations in corneal shape.
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http://dx.doi.org/10.3928/1081597X-20090617-01 | DOI Listing |
Int Med Case Rep J
January 2025
Department of Ophthalmology, University of California San Francisco, San Francisco, CA, USA.
Purpose: To compare the outcomes of two different surgical planning strategies for topography-guided repair of post-LASIK ectasia.
Methods: This is a case report of a patient presenting with post-LASIK ectasia. A retrospective chart review was used to collect details of the ophthalmic exam, as well as ocular imaging such as anterior segment optical coherence tomography and Scheimpflug corneal tomography.
Eye (Lond)
January 2025
Bio-manufacturing Engineering Laboratory, International Graduate School at Shenzhen, Tsinghua University, Shenzhen, Guangdong, China.
Objectives: To propose and evaluate a novel, non-invasive approach for enduring corneal astigmatism correction based on topography-guided, patterned, customized riboflavin-ultraviolet A corneal collagen crosslinking (CXL).
Methods: Astigmatism was modelled on both eyes of rabbits. A randomly selected eye of each rabbit was treated by the proposed CXL procedure with another eye as control.
BMC Ophthalmol
January 2025
Department of Ophthalmology, Eye & ENT Hospital, Fudan University, 83 Fenyang Road, Xuhui District, Shanghai, 200031, China.
Background: To investigate the impact of central corneal astigmatism on postoperative visual outcomes in patients with trifocal intraocular lens (IOL) implantation.
Methods: This retrospective study included 278 eyes of 278 patients who underwent uneventful cataract surgery with implantation of the trifocal IOL (AT LISA tri 839MP). Patients were divided into two groups according to the total corneal refractive power (TCRP) in 3 mm zone centered on the corneal apex: low astigmatism group, TCRP ≤ 0.
Clin Exp Optom
January 2025
Department of Ophthalmology, Adana City Training and Research Hospital, Adana, Turkey.
Clinical Relevance: Horizontal rectus muscle surgeries may cause changes in corneal and anterior segment parameters. Corneal topography is an important device for identifying these alterations.
Background: The aim of this work is to evaluate the effects of horizontal rectus muscle surgeries on corneal topography, anterior chamber parameters and corneal wavefront aberrations.
J Clin Med
December 2024
The David J Apple Center for Vision Research, Department of Ophthalmology, Heidelberg University Eye Clinic, University Hospital Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany.
This laboratory study aims to assess the effects of misaligning different trifocal intraocular lenses (IOLs) under varying spectral and corneal spherical aberration (SA) conditions. With an IOL metrology device under monochromatic and polychromatic conditions, the following models were studied: AT ELANA 841P, AT LISA Tri 839MP, FineVision HP POD F, Acrysof IQ PanOptix, and Tecnis Synergy ZFR00V. The SA was simulated using an aberration-free and average-SA cornea.
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