Background: The aim of this study was to investigate the changes in corneal epithelial thickness along the principle meridians of astigmatic corneas after six months of overnight spherical myopic orthokeratology (OK) lens wear.
Methods: This is a prospective study. Fifty-seven subjects with up to 1.50 diopters (D) of corneal toricity wore spherical OK lenses for 6 months. Evaluations of OK lens fit, visual acuity, refractions and corneal toricity (CT) were performed. Fourier-domain optical coherence tomography (FD-OCT) was conducted to measure the corneal epithelial thickness (ET) along the principle meridians of corneal toricity over a diameter of 6 mm. The means of △ET of the same diameter at individual meridians (△ETSm and △ETFm) were calculated and compared.
Results: Visual acuity and refraction improved significantly after OK lens wear. △ETFm thinned more than △ETSm (P = 0.027) at 1.5 mm in radius. △ETSm thickened more than △ETFm at 2.5 mm (P = 0.019) and 3.0 mm (P = 0.036).∣△ETSm - △ETFm∣ were significantly correlated with the baseline central CT at 2.0 mm, 2.5 mm and 3.0 mm. ∣△ETSm - △ETFm∣was significantly correlated with the baseline peripheral CT at 2.5 mm.
Conclusions: Overnight wear of spherical OK lenses resulted in differential changes in the thickness profiles of the corneal epithelium between the steep and flat meridians in eyes with corneal toricity.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7304131 | PMC |
http://dx.doi.org/10.1186/s12886-020-01477-y | DOI Listing |
Background: To determine whether accounting for posterior corneal surgically induced astigmatism (SIA) would improve toric intraocular lens power calculation prediction error.
Methods: A total of 189 eyes of 148 patients undergoing routine cataract surgery were included in the study. Standard and posterior keratometry were measured pre- and postoperatively.
Cont Lens Anterior Eye
January 2025
Laboratory of Optometry and Vision Sciences, West China School of Medicine, Sichuan University, Chengdu, China; Department of Optometry and Vision Sciences, West China School of Medicine, Sichuan University, Chengdu, China.
Objective: To investigate changes in corneal astigmatism (curvatures and corneal sagittal height difference (C-sagDiff) at 8-mm chord) after temporary discontinuation from long-term spherical and toric orthokeratology (ortho-k) lens wear in a Chinese population.
Methods: Relevant data were retrieved from 110 patients (55 wearing spherical ortho-k lenses, 55 wearing toric ortho-k lenses) who have been undergoing ortho-k treatment for at least one year and stopped lens wear temporarily for scheduled lens replacement. The topographic and refraction data at baseline and post-discontinuation was collected for all the patients.
Graefes Arch Clin Exp Ophthalmol
December 2024
Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University, No. 83 Fenyang Road, Shanghai, 200031, China.
Purpose: To compare the precision of the arithmetic mean of surgically induced astigmatism (M-SIA) and the centroid of surgically induced astigmatism (C-SIA) in estimating SIA when predicting the power and axis of toric IOLs under different circumstances.
Methods: 120 eyes of 99 patients undergoing toric IOL replacement in a simple cataract surgery were included in the retrospective study. The predicted position of toric IOL was calculated by Z Calc online calculator and Barrett Toric Calculator with M-SIA (0.
Clin Ophthalmol
December 2024
Department of Refractive Surgery, Eye Clinic Sistina Oftalmologija, Skopje, 1000 Republic of North Macedonia.
Purpose: To explore the significance of changes in anterior chamber depth (ΔACD) and astigmatism between 4 and 8 weeks following uneventful phacoemulsification.
Patients And Methods: Anterior chamber depth (ACD, mm), autorefractometry and subjective refraction were monitored in pseudophakic eyes implanted with non-toric IOLs (group 1, SA60AT, n=36; group 2, SN60WF, n=34; group 3, ICBOO, n=16) and phakic control group (n=30, group 4a, for ACD and autorefractometry) over four weeks. Changes in subjective refractions were compared with repeatability in normal phakic eyes (n=30, group 4b).
Purpose: To compare 6-month visual outcomes and optical quality after small incision lenticule extraction (SMILE) and toric Implantable Collamer Lens (ICL) (STAAR Surgical Company) implantation for high myopia astigmatism.
Methods: This was a prospective non-randomized study. Overall, 88 eyes of 88 patients with high astigmatism (≥ 2.
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