98%
921
2 minutes
20
Objective: To calculate the values from the human anterior corneal surface with the tangential radius of curvature and analyze its distribution characteristics in different age and refractive status groups.
Methods: Tangential power maps of the anterior cornea from Orbscan II were acquired for 201 subjects' right eyes. They were divided into groups of adults and children and then divided further into subgroups according to the refraction status. The values of each semimeridian were calculated by the tangential radius with a linear regression equation. The value distribution in both the nasal cornea and temporal cornea were analyzed.
Results: The mean temporal values of the emmetropia group of adults and all children's groups were significantly different from the mean nasal value. The mean nasal corneal values were more negative in children. The adult group showed differences only in the low myopia group. The mean value of the nasal cornea among different refractive groups of children was significantly different, and so was the temporal cornea between the adult myopia and emmetropia group.
Conclusion: The method using the tangential radius of curvature combined with linear regression to obtain anterior surface values for both adults and children was stable and reliable. When we analyzed the anterior corneal value, area division was necessary.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5932450 | PMC |
http://dx.doi.org/10.1155/2018/7263564 | DOI Listing |
J Clin Med
August 2025
BG Klinik Ludwigshafen, Department for Orthopaedics and Trauma Surgery at Heidelberg University, Ludwig-Guttmann-Str. 13, 67071 Ludwigshafen, Germany.
: Dorsal screw protrusion or intra-articular screw penetration at the distal radius can cause extensor tendon injuries or articular surface damage. Despite the use of various views, the detection of screw misplacement remains limited in 2D fluoroscopy. This study compares the sensitivity of 2D and 3D fluoroscopy for detecting screw misplacement at the distal radius.
View Article and Find Full Text PDFImaging Neurosci (Camb)
August 2025
Department of Biomedical Engineering, University of Alberta, Edmonton, Alberta, Canada.
The human cortex undergoes significant macrostructural and microstructural changes across the lifespan, which can be assessed using high-resolution diffusion tensor imaging (DTI). In healthy individuals, diffusion is typically greater perpendicular to the cortical surface, aligning with neuronal bodies and apical dendrites. This study examined DTI metrics in 190 healthy individuals (ages 5-74 years) to characterize normative cortical changes across neurodevelopment and aging.
View Article and Find Full Text PDFMultilayer coated toroidal mirrors have been widely used in X-ray optical systems to focus/collimate the X-ray beams. The variation of grazing incidence angles at different positions in the tangential direction of the toroidal mirror necessitates a lateral gradient of the multilayer d-spacing. Additionally, a small radius of curvature (RoC) in the sagittal direction and the compact size of the mirror make the deposition more difficult.
View Article and Find Full Text PDFMaterials (Basel)
June 2025
School of Engineering, University of Auckland, Auckland 0632, New Zealand.
The torsional stiffness of rehabilitation robot joints is a critical performance determinant, significantly affecting motion accuracy, stability, and user comfort. This paper introduces an innovative traction drive mechanism that transmits torque through friction forces, overcoming mechanical impact issues of traditional gear transmissions, though accurately modeling surface roughness effects remains challenging. Based on fractal theory, this study presents a comprehensive torsional stiffness analysis for advanced traction drive joints.
View Article and Find Full Text PDFJ Hand Surg Glob Online
July 2025
Division for Orthopaedics and Traumatology, Cantonal Hospital Winterthur, Winterthur, Zurich, Switzerland.
Purpose: Dorsal screw tip protrusion (DSTP) with extensor tendon injury is a well-known complication after volar plating of the distal radius. Specific fluoroscopic views such as the dorsal tangential view (DTV) and the radial groove view (RGV) have been recommended to detect DSTP. The aim of this study was to investigate the accuracy of these views before and after standardized teaching of the involved surgeons.
View Article and Find Full Text PDF