Purpose: This study was designed to identify factors that predict longitudinal increases in corneal curvature as measured by the First Definite Apical Clearance Lens (FDACL) and flatter keratometric reading (Flat K) in keratoconus.
Methods: The Collaborative Longitudinal Evaluation of Keratoconus (CLEK) Study is a long-te rm evaluation of the natural history of keratoconus involving 1209 patients. This report uses 8 years of follow-up data from 1032 patients who had penetrating keratoplasty in neither eye at baseline and who provided enough data to compute the slope of the change with time in the FDACL or the Flat K. Outcome measures included the aforementioned slopes and whether the FDACL or the Flat K increased by 3.00 or more diopters (D) in at least 1 eye.
Results: At CLEK Study entry, patients were aged 38.9 +/- 10.8 years. Overall, 44.3% of them were women, and 69.3% of them were white. The slope of the change in FDACL (0.18 +/- 0.60 D/y) and Flat K (0.20 +/- 0.80 D) during 8 years translates into expected 8-year increases of 1.44 D in FDACL and 1.60 D in Flat K. Increases of > or = 3.00 D in either eye had an 8-year incidence of 24.8% for FDACL and 24.1% for Flat K. Independent predictors of increased FDACL included younger age, poorer baseline high-contrast manifest refraction visual acuity, and non-white race. Younger age and poorer high-contrast manifest refraction visual acuity were independent predictors of a >3.00-D increase for both FDACL and Flat K.
Conclusion: CLEK patients exhibited a slow but clear increase in corneal curvature. Younger age and poorer high-contrast manifest refraction visual acuity at baseline predicted the rate of change in corneal curvature.
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http://dx.doi.org/10.1097/01.ico.0000178728.57435.df | DOI Listing |
J Optom
January 2025
Department of Ophthalmology, Antwerp University Hospital, Edegem, Belgium; Visual Optics Lab Antwerp (VOLANTIS), Faculty of Medicine and Health Sciences, Antwerp University, Wilrijk, Belgium. Electronic address:
Background: The maximum accommodative range is a useful indication of visual function. It decreases with age, but the exact cause of this decrease is not fully understood. It is associated with the increasing rigidity of the lens and changes to the lens shape, as well as the geometry of the zonular attachments.
View Article and Find Full Text PDFComplement Med Res
January 2025
Eye Hospital, China Academy of Chinese Medical Sciences, Beijing, China.
Background: The increasing prevalence of myopia among Chinese children and adolescents, especially at younger ages, has emerged as a significant concern in recent years. Pre-myopia is a key period for myopia prevention and control in children and adolescents. Previous studies suggested auricular acupressure (AA) therapy might offer a viable approach to prevent and slow down myopia progression.
View Article and Find Full Text PDFJ Clin Med
December 2024
Ocupharm Research Group, Department of Optometry and Vision, Faculty of Optics and Optometry, Complutense University of Madrid, 28037 Madrid, Spain.
: The objective of this study was to examine the trend of treatment zone (TZ) decentration over 12 months of orthokeratology (OK) wear using two Corneal Refractive Therapy (CRT) lens designs: standard (STD) and dual axis (DA). : A prospective, randomized, longitudinal study was conducted at the Optometry Clinic of the Complutense University of Madrid. Subjects were randomly fitted with an STD design or DA design in one of the eyes.
View Article and Find Full Text PDFFront Med (Lausanne)
December 2024
Chongqing Key Laboratory of Prevention and Treatment on Major Blinding Diseases, Chongqing Eye Institute, Chongqing Branch (Municipality Division) of National Clinical Research Center for Ocular Diseases, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China.
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.
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