Background: To determine the influence of the magnitude of treatment zone decentration on axial length (AL) elongation and to investigate the association between paracentral corneal asymmetry and orthokeratology (OK) lens decentration.
Methods: This retrospective study involved 268 subjects (7-14 years) who wore OK lenses for one year. The parameters that reflected the paracentral corneal asymmetry were recorded: corneal toricity; Q value; anterior corneal curvature; and elevation values at the 6-, 7-, and 8-mm chords along the horizontal meridian. The relationships between these data and the amount of treatment zone decentration were analyzed. The relationship of the decentration magnitude and AL elongation was also analyzed.
Results: AL elongation was significantly associated with initial age, baseline spherical equivalent, AL, and the decentration magnitude. The subjects with large decentration magnitude showed less AL elongation. The decentration was affected by corneal morphology at the 8-mm chord on the nasal side. In the low curvature group (≤41.0D), the decentration magnitude had a stronger correlation with AL elongation than in all subjects. In the high curvature group (>41.0D), the decentration magnitude was no longer correlated with the AL elongation.
Conclusion: The decentration of the OK lens effectively slowed the elongation of the eyeball. When the nasal curvature was less than 41.0 D at the 8-mm chord, the magnitude of decentration was predetermined by the flatter curve.
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http://dx.doi.org/10.1097/ICL.0000000000000985 | DOI Listing |
Cont Lens Anterior Eye
February 2025
Department of Ophthalmology & Clinical Center of Optometry, Peking University People's Hospital, Beijing 100044, China; College of Optometry, Peking University Health Science Center, Beijing, China; Eye Disease and Optometry Institute, Peking University People's Hospital; Beijing Key Laboratory of Diagnosis and Therapy of Retinal and Choroid Diseases. Electronic address:
Background: To assess the predictive value of pretreatment corneal elevation asymmetry vector (CEAV) for severe orthokeratology (Ortho-k) lens decentration (LD) in Chinese myopic adolescents.
Methods: A retrospective analysis of 247 myopic participants over one year employed a novel MATLAB algorithm to calculate CEAV and precise LD vector. Subjects were categorized into mild (<1 mm) and severe (≥1 mm) yearly averaged LD (YALD) groups.
Ophthalmic Physiol Opt
January 2025
The Eye Hospital, School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, China.
Purpose: To discuss the characteristics of anterior corneal elevation asymmetry in myopic eyes and clarify which kind of asymmetry most influenced lens position.
Methods: In this retrospective study of 199 consecutive myopic participants, corneal topography was used to analyse asymmetry in anterior corneal elevation. Amongst them, 65 participants (65 eyes) who underwent orthokeratology (31 and 34 with spherical and toric lenses, respectively) were re-evaluated.
BMC Ophthalmol
October 2024
Department of Ophthalmology, University of Ulsan College of Medicine, Asan Medical Center, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, 05505, South Korea.
Purpose: To compare long-term intraocular lens (IOL) decentration and tilt following femtosecond laser-assisted cataract surgery (FLACS) and conventional surgery using swept-source anterior segment ocular coherence tomography (SS-ASOCT).
Methods: In this retrospective cross-sectional study, all patients underwent FLACS or conventional cataract surgery. Those with a minimum of 12-months follow-up since surgery were included.
J Clin Med
September 2024
Department of Materials, Design and Manufacturing Engineering, School of Engineering, University of Liverpool, Liverpool L69 3GH, UK.
Purpose: To assess the influence of ocular biometric parameters on intraocular lens (IOL) tilt and decentration after cataract surgery.
Methods: Patients scheduled for cataract surgery were screened for inclusion in this prospective cohort study. Tilt and decentration of the crystalline lens and IOL were measured using the CASIA2 (Tomey).
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