| 1. |
- Bentham, James, et al.
(author)
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A century of trends in adult human height
- 2016
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In: eLIFE. - : eLife Sciences Publications Ltd. - 2050-084X. ; 5
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Journal article (peer-reviewed)abstract
- Being taller is associated with enhanced longevity, and higher education and earnings. We reanalysed 1472 population-based studies, with measurement of height on more than 18.6 million participants to estimate mean height for people born between 1896 and 1996 in 200 countries. The largest gain in adult height over the past century has occurred in South Korean women and Iranian men, who became 20.2 cm (95% credible interval 17.5–22.7) and 16.5 cm (13.3– 19.7) taller, respectively. In contrast, there was little change in adult height in some sub-Saharan African countries and in South Asia over the century of analysis. The tallest people over these 100 years are men born in the Netherlands in the last quarter of 20th century, whose average heights surpassed 182.5 cm, and the shortest were women born in Guatemala in 1896 (140.3 cm; 135.8– 144.8). The height differential between the tallest and shortest populations was 19-20 cm a century ago, and has remained the same for women and increased for men a century later despite substantial changes in the ranking of countries.
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| 2. |
- Bixby, H., et al.
(author)
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Rising rural body-mass index is the main driver of the global obesity epidemic in adults
- 2019
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In: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 569:7755, s. 260-4
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Journal article (peer-reviewed)abstract
- Body-mass index (BMI) has increased steadily in most countries in parallel with a rise in the proportion of the population who live in cities(.)(1,2) This has led to a widely reported view that urbanization is one of the most important drivers of the global rise in obesity(3-6). Here we use 2,009 population-based studies, with measurements of height and weight in more than 112 million adults, to report national, regional and global trends in mean BMI segregated by place of residence (a rural or urban area) from 1985 to 2017. We show that, contrary to the dominant paradigm, more than 55% of the global rise in mean BMI from 1985 to 2017-and more than 80% in some low- and middle-income regions-was due to increases in BMI in rural areas. This large contribution stems from the fact that, with the exception of women in sub-Saharan Africa, BMI is increasing at the same rate or faster in rural areas than in cities in low- and middle-income regions. These trends have in turn resulted in a closing-and in some countries reversal-of the gap in BMI between urban and rural areas in low- and middle-income countries, especially for women. In high-income and industrialized countries, we noted a persistently higher rural BMI, especially for women. There is an urgent need for an integrated approach to rural nutrition that enhances financial and physical access to healthy foods, to avoid replacing the rural undernutrition disadvantage in poor countries with a more general malnutrition disadvantage that entails excessive consumption of low-quality calories.
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| 3. |
- Sundström, Johan, Professor, 1971-, et al.
(author)
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Risk factors for subarachnoid haemorrhage : a nationwide cohort of 950 000 adults
- 2019
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In: International Journal of Epidemiology. - : Oxford University Press. - 0300-5771 .- 1464-3685. ; 48:6, s. 2018-2025
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Journal article (peer-reviewed)abstract
- BACKGROUND: Subarachnoid haemorrhage (SAH) is a devastating disease, with high mortality rate and substantial disability among survivors. Its causes are poorly understood. We aimed to investigate risk factors for SAH using a novel nationwide cohort consortium.METHODS: We obtained individual participant data of 949 683 persons (330 334 women) between 25 and 90 years old, with no history of SAH at baseline, from 21 population-based cohorts. Outcomes were obtained from the Swedish Patient and Causes of Death Registries.RESULTS: During 13 704 959 person-years of follow-up, 2659 cases of first-ever fatal or non-fatal SAH occurred, with an age-standardized incidence rate of 9.0 [95% confidence interval (CI) (7.4-10.6)/100 000 person-years] in men and 13.8 [(11.4-16.2)/100 000 person-years] in women. The incidence rate increased exponentially with higher age. In multivariable-adjusted Poisson models, marked sex interactions for current smoking and body mass index (BMI) were observed. Current smoking conferred a rate ratio (RR) of 2.24 (95% CI 1.95-2.57) in women and 1.62 (1.47-1.79) in men. One standard deviation higher BMI was associated with an RR of 0.86 (0.81-0.92) in women and 1.02 (0.96-1.08) in men. Higher blood pressure and lower education level were also associated with higher risk of SAH.CONCLUSIONS: The risk of SAH is 45% higher in women than in men, with substantial sex differences in risk factor strengths. In particular, a markedly stronger adverse effect of smoking in women may motivate targeted public health initiatives.
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| 4. |
- Brusini, Irene, et al.
(author)
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Fully automatic estimation of the waist of the nerve fiber layer at the optic nerve head angularly resolved
- 2021
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In: Progress in Biomedical Optics and Imaging - Proceedings of SPIE. - : SPIE-Intl Soc Optical Eng. ; , s. 1D1-1D8
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Conference paper (peer-reviewed)abstract
- The present project aims at developing a fully automatic software for estimation of the waist of the nerve fiber layer in the Optic Nerve Head (ONH) angularly resolved in the frontal plane as a tool for morphometric monitoring of glaucoma. The waist of the nerve fiber layer is here defined as Pigment epithelium central limit –Inner limit of the retina – Minimal Distance, (PIMD). 3D representations of the ONH were collected with high resolution OCT in young not glaucomatous eyes and glaucomatous eyes. An improved tool for manual annotation was developed in Python. This tool was found user friendly and to provide sufficiently precise manual annotation. PIMD was automatically estimated with a software consisting of one AI model for detection of the inner limit of the retina and another AI model for localization of the Optic nerve head Pigment epithelium Central limit (OPCL). In the current project, the AI model for OPCL localization was retrained with new data manually annotated with the improved tool for manual annotation both in not glaucomatous eyes and in glaucomatous eyes. Finally, automatic annotations were compared to 3 annotations made by 3 independent annotators in an independent subset of both the not glaucomatous and the glaucomatous eyes. It was found that the fully automatic estimation of PIMD-angle overlapped the 3 manual annotators with small variation among the manual annotators. Considering interobserver variation, the improved tool for manual annotation provided less variation than our original annotation tool in not glaucomatous eyes suggesting that variation in glaucomatous eyes is due to variable pathological anatomy, difficult to annotate without error. The small relative variation in relation to the substantial overall loss of PIMD in the glaucomatous eyes compared to the not glaucomatous eyes suggests that our software for fully automatic estimation of PIMD-angle can now be implemented clinically for monitoring of glaucoma progression.
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| 5. |
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| 8. |
- Kisonaite, Konstancija, et al.
(author)
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AI-based detection of the inner limit of the minimal waist of the nerve fiber bundles in the ONH in subjects with peripapillary atrophy
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Other publication (other academic/artistic)abstract
- Purpose: To verify that a deep learning model developed by our research group does not wrongly identify the outer edge of the atrophic zone in eyes with peripapillary atrophy (PPA) rather than a point adjacent to the external limit of the minimal waist of the nerve fiber bundles in the ONH.Methods: Subjects with at least one eye with PPA were included. The ONH of the eye with PPA was imaged with colour photography, and the three-dimensional structure of the ONH was captured three times at one occasion with SS-OCT (Topcon Triton, Japan). Each capture was exported to a custom-made software for analysis. The custom-made software, AutoPimd, allowed fully automatic localization of the external limit of the minimal waist of the nerve fiber layer in space using deep learning-model. An en face visualization of the frontal plane of the ONH and user measurement in the en face view is possible. The en face view in the OCT volume was verified to render PPA as imaged in the photograph. The distance between the ONH center and the extreme edge of the PPA was measured in the en face view of the OCT. Then, the frontal plane distance between the ONH center and the fully automatically detected external limit of the minimal waist of the nerve fiber layer in the ONH was measured along the same frontal plane angle.Results: A 95 % confidence interval for the mean difference between the distance from center of the ONH to the extreme edge of the PPA, and the distance from the center of the ONH to the corresponding fully automatically detected outer limit of the minimal waist of the nerve fiber layer was estimated to 692 ± 192 μm (d.f = 5).Conclusion: Our AI model does not wrongly localize the outer limit of PPA as the external limit of the minimal waist of the nerve fiber layer. The structural representation of the external limit of the minimal waist of the nerve fiber bundles localized by our fully automatic AI model in eyes with PPA remains to be identified.
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| 9. |
- Kisonaite, Konstancija, et al.
(author)
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Automatic estimation of the cross-sectional area of the waist of the nerve fiber layer at the optic nerve head
- 2023
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In: Acta Ophthalmologica. - : John Wiley & Sons. - 1755-375X .- 1755-3768.
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Journal article (peer-reviewed)abstract
- PurposeGlaucoma leads to pathological loss of axons in the retinal nerve fibre layer at the optic nerve head (ONH). This study aimed to develop a strategy for the estimation of the cross-sectional area of the axons in the ONH. Furthermore, improving the estimation of the thickness of the nerve fibre layer, as compared to a method previously published by us.MethodsIn the 3D-OCT image of the ONH, the central limit of the pigment epithelium and the inner limit of the retina, respectively, were identified with deep learning algorithms. The minimal distance was estimated at equidistant angles around the circumference of the ONH. The cross-sectional area was estimated by the computational algorithm. The computational algorithm was applied on 16 non-glaucomatous subjects.ResultsThe mean cross-sectional area of the waist of the nerve fibre layer in the ONH was 1.97 ± 0.19 mm2. The mean difference in minimal thickness of the waist of the nerve fibre layer between our previous and the current strategies was estimated as CIμ (0.95) 0 ± 1 μm (d.f. = 15).ConclusionsThe developed algorithm demonstrated an undulating cross-sectional area of the nerve fibre layer at the ONH. Compared to studies using radial scans, our algorithm resulted in slightly higher values for cross-sectional area, taking the undulations of the nerve fibre layer at the ONH into account. The new algorithm for estimation of the thickness of the waist of the nerve fibre layer in the ONH yielded estimates of the same order as our previous algorithm.
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| 10. |
- Kisonaite, Konstancija, et al.
(author)
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Estimation of the cross-sectional surface area of the waist of the nerve fiber layer at the optic nerve head
- 2022
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In: Progress in Biomedical Optics and Imaging. - : SPIE-Intl Soc Optical Eng.
-
Conference paper (peer-reviewed)abstract
- Glaucoma is a global disease that leads to blindness due to pathological loss of retinal ganglion cell axons in the optic nerve head (ONH). The presented project aims at improving a computational algorithm for estimating the thickness and surface area of the waist of the nerve fiber layer in the ONH. Our currently developed deep learning AI algorithm meets the need for a morphometric parameter that detects glaucomatous change earlier than current clinical follow-up methods. In 3D OCT image volumes, two different AI algorithms identify the Optic nerve head Pigment epithelium Central Limit (OPCL) and the Inner limit of the Retina Closest Point (IRCP) in a 3D grid. Our computational algorithm includes the undulating surface area of the waist of the ONH, as well as waist thickness. In 16 eyes of 16 non-glaucomatous subjects aged [20;30] years, the mean difference in minimal thickness of the waist of the nerve fiber layer between our previous and the current post-processing strategies was estimated as CIμ(0.95) 0 ±1 μm (D.f. 15). The mean surface area of the waist of the nerve fiber layer in the optic nerve head was 1.97 ± 0.19 mm2. Our computational algorithm results in slightly higher values for surface areas compared to published work, but as expected, this may be due to surface undulations of the waist being considered. Estimates of the thickness of the waist of the ONH yields estimates of the same order as our previous computational algorithm.
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| 11. |
- Kisonaite, Konstancija
(author)
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Quantitative assessment of glaucoma by artificial intelligence estimation of the waist of the nerve fiber layer in the optic nerve head
- 2023
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Licentiate thesis (other academic/artistic)abstract
- Glaucoma is a chronic progressive disease that causes loss of retinal ganglion cells, which impairs the visual field. In optic coherence tomography (OCT) image, the retinal ganglion cell (RGC) axons in the optic nerve head (ONH) can be quantified as the minimal thickness from the ONH Pigmental epithelium Central Limit (OPCL) to the Inner limit of the Retina Closest Point (IRCP). Alternatively, the minimal cross-sectional surface area can be measured. In peripapillary atrophy, the morphometry of the retinal pigmental epithelium is affected.Purpose: To design and test a new computational algorithm for estimation of Pigment epithelium to Inner limit of the Retina Minimal Area (PIMA) and evaluate a new method to estimate the Pigment epithelium to Inner limit of the Retina Minimal Distance (PIMD). OPCL can be detected and annotated by a deep learning algorithm in individuals with peripapillary atrophy.Methods: A deep learning algorithm has been trained to automatically detect OPCL, IRCP and calculate PIMD. A new computational algorithm was developed to estimate PIMA in OCT images of young adults. The mean between the first and second version of estimating PIMD was evaluated. The difference of distance between the ONH center-OPCL and ONH center-atrophic edge was estimated in eyes with peripapillary atrophy.Results: A 95% confidence interval for PIMA-2π was estimated to 1.97 ± 0.19 mm2 (df = 15). A confidence interval for the difference between PIMDv1-2π and PIMDv2-2π was 0 ± 1 μm (df = 15). A 95 % confidence interval for the mean difference between ONH-OPCL and ONH-atrophic edge was estimated to 692 ± 192 µm (df = 5).Conclusions: The computational algorithm for estimation of PIMA was developed and applied. An initial analysis indicated the capacity of the deep learning algorithm to detect OPCL in subjects with PPA.Keywords: deep learning, optic nerve head, ONH, retinal pigmental epithelium, RPE, PIMD, PIMD-2π, minimal distance, PIMA, PIMA-2π, minimal area, peripapillary atrophy, PPA, optic coherence tomography, OCT, glaucoma, quantification, retinal ganglion cell axons
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| 12. |
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| 13. |
- Mathew, Jessica, et al.
(author)
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Lamellar changes in the keratoconic cornea
- 2015
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In: Acta Ophthalmologica Scandinavica. - : Wiley. - 1395-3907 .- 1600-0420 .- 1755-375X. ; 93:8, s. 767-773
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Journal article (peer-reviewed)
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| 14. |
- Meyer, Linda, et al.
(author)
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Ultrastructure of UVR-B-induced cataract and repair visualized with electron microscopy
- 2014
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In: Acta Ophthalmologica. - : Wiley. - 1755-375X .- 1755-3768. ; 92:7, s. 635-643
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Journal article (peer-reviewed)abstract
- PurposeThe aim of the study is to investigate and visualize the ultrastructure of cataract morphology and repair, after in vivo exposure to double threshold dose UVR-B in the C57BL/6 mouse lens.MethodsTwenty-six-week-old C57BL/6 mice received in vivo double threshold dose (6.4 kJ/m2) UVR-B for 15 min. The radiation output of the UVR-source had λMAX at 302.6 nm. After a latency period of 1, 2, 4 and 8 days following UVR-B exposure, the induced cataract was visualized with electron microscopy techniques. Induced, cataract was quantified as forward lens light scattering. Damage to the lens epithelium and the anterior cortex was investigated with light microscopy in toluidine blue-stained semi-thin sections, transmission electron microscopy (TEM), scanning electron microscopy (SEM) and dark field illumination photography.ResultsUVR-B-exposed lenses developed anterior subcapsular and/or cortical and nuclear cataract after 1 day. Lens light scattering peaked 2 days after exposure. Lens epithelial cell damage was seen in TEM as apoptotic cells, apoptotic bodies, nuclear chromatin condensation, and swollen and disrupted anterior cortex fibres throughout the sections of the whole anterior lens surface. These morphologic changes were also visualized with SEM. Within 8 days, anterior subcapsular cataract was repaired towards the anterior sutures.ConclusionUVR-B exposure of double cataract threshold dose induces a subtotal loss of epithelial cells across the whole anterior surface of the lens. This damage to the epithelium is repaired by epithelial cell movement from the equator towards the lens sutures, thus in retrograde direction to regular epithelial cell differentiation.
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| 15. |
- Mittal, Nitesh, et al.
(author)
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Multiscale Control of Nanocellulose Assembly : Transferring Remarkable Nanoscale Fibril Mechanics to Macroscale Fibers
- 2018
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In: ACS Nano. - : American Chemical Society (ACS). - 1936-0851 .- 1936-086X. ; 12:7, s. 6378-6388
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Journal article (peer-reviewed)abstract
- Nanoscale building blocks of many materials exhibit extraordinary mechanical properties due to their defect-free molecular structure. Translation of these high mechanical properties to macroscopic materials represents a difficult materials engineering challenge due to the necessity to organize these building blocks into multiscale patterns and mitigate defects emerging at larger scales. Cellulose nanofibrils (CNFs), the most abundant structural element in living systems, has impressively high strength and stiffness, but natural or artificial cellulose composites are 3-15 times weaker than the CNFs. Here, we report the flow-assisted organization of CNFs into macroscale fibers with nearly perfect unidirectional alignment. Efficient stress transfer from macroscale to individual CNF due to cross-linking and high degree of order enables their Young's modulus to reach up to 86 GPa and a tensile strength of 1.57 GPa, exceeding the mechanical properties of known natural or synthetic biopolymeric materials. The specific strength of our CNF fibers engineered at multiscale also exceeds that of metals, alloys, and glass fibers, enhancing the potential of sustainable lightweight high-performance materials with multiscale self-organization.
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| 16. |
- Naredi, Peter, 1955, et al.
(author)
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The influence of hepatic artery ligation and of vasopressin on liver tumour blood flow in rats.
- 1992
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In: Journal of surgical oncology. - : Wiley. - 0022-4790 .- 1096-9098. ; 50:2, s. 70-6
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Journal article (peer-reviewed)abstract
- The blood flow in an experimental adenocarcinoma in the rat liver was determined with the 133Xe-washout technique before and after hepatic artery ligation (HAL). There was an initial reduction of the washout of 50%. This was further reduced after 1 day by 50%, which was maintained for 7 days. Seven days after HAL or sham procedures the 133Xe-washout was of similar magnitude in the liver tumours, although after the sham procedure the tumours were larger (3.4 g vs. 1.5 g). The estimated tumour blood flow was then approximately 0.04 ml x min-1 x g-1. The influence on normal liver parenchyma of HAL was a reduction at 30 minutes, which was maintained for 7 days. Postacton--a synthetic vasopressin--did not influence the 133Xe-washout in normal liver parenchyma in non-tumour, as well as in tumour-bearing animals. There was no influence of Postacton on the 133Xe-washout in the liver tumours. Thirty minutes after HAL Postacton gave a reduction of blood flow in normal liver parenchyma of tumour-bearing animals, which is thus only from the portal vein. In tumours Postacton did not significantly reduce the tumour blood flow immediately after HAL.
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| 17. |
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| 18. |
- Nordenström, Malin, et al.
(author)
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The structure of cellulose nanofibril networks at low concentrations and their stabilizing action on colloidal particles
- 2022
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In: Carbohydrate Polymers. - : Elsevier BV. - 0144-8617 .- 1879-1344. ; 297, s. 120046-
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Journal article (peer-reviewed)abstract
- The structure and dynamics of networks formed by rod-shaped particles can be indirectly investigated by measuring the diffusion of spherical tracer particles. This method was used to characterize cellulose nanofibril (CNF) networks in both dispersed and arrested states, the results of which were compared with coarse-grained Brownian dynamics simulations. At a CNF concentration of 0.2 wt% a transition was observed where, below this concentration tracer diffusion is governed by the increasing macroscopic viscosity of the dispersion. Above 0.2 wt%, the diffusion of small particles (20-40 nm) remains viscosity controlled, while particles (100-500 nm) become trapped in the CNF network. Sedimentation of silica microparticles (1-5 mu m) in CNF dispersions was also determined, showing that sedimentation of larger particles is significantly affected by the presence of CNF. At concentrations of 0.2 wt%, the sedimentation velocity of 5 mu m particles was reduced by 99 % compared to pure water.
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| 30. |
- Sandberg Melin, Camilla
(author)
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Morphometry of the Optic Nerve Head as a Diagnostic Tool for Glaucoma
- 2019
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Doctoral thesis (other academic/artistic)abstract
- Glaucoma is a chronic optic nerve head (ONH) disease. Gradual retinal ganglion cell and nerve fiber loss lead to morphological ONH change and visual field defects. Initial loss is often focal. Rate of progression and life expectancy guide treatment. Currently, confocal scanning laser tomoghraphy (HRT) and optic coherence tomography (OCT) are available for ONH imaging. However, there is no consensus for which morphometric measurement of ONH nerve fiber content to use for glaucoma follow-up.Purpose: To measure ONH nerve fiber content as neuroretinal rim area (NRA) with HRT, estimate NRA measurement variation and its impact on designing a follow-up strategy. To develop a custom algorithm, Pigment epithelium central limit-Inner limit of the retina Minimal Distance (PIMD), for measuring ONH nerve fiber content in OCT data cubes. To measure PIMD in glaucomatous eyes, estimate the variance sources for PIMD and their impact on designing strategies for glaucoma follow-up.Methods: NRA was measured with HRT in non-glaucomatous and glaucomatous eyes. Sources of variance for NRA were estimated. An OCT data cube of a non-glaucomatous eye was used in developing the PIMD algorithm. PIMD was measured in 500 radii along the ONH circumference. PIMD averaged over the circumference is PIMD-2π. Sources of variance for PIMD-2π were estimated for glaucomatous eyes. Strategies for following PIMD-2π and segments of PIMD-2π within subject over time were proposed.Results: Variation among subjects was substantial for NRA and PIMD-2π. Contrarily, within subject variation was small for NRA and PIMD-2π. When within subject variation, a previously reported loss rate for progressing glaucoma, and measuring NRA 3 times every 4 months were applied, a significant loss was detected after 54 months. When within subject variation and a PIMD-2π loss rate resulting in blindness after 20 years were applied, a significant PIMD-2π loss was detected in 16 months with visits every 4 months. Within subject segmental PIMD-2π loss can be detected from the 3rd visit. Loss rate of each PIMD can be estimated with linear regression from the 4th visit. Change in segmental PIMD-2π loss rate can be detected at a later visit.Conclusions: Small within subject variation allows for within subject NRA and PIMD follow-up over time. Segmental PIMD-2π has potential to detect focal glaucomatous defects and worsening of existing defects. There is potential to detect a change in segmental PIMD-2π loss rate. Segmental PIMD-2π has potential as a tool for within subject follow-up of glaucoma.
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| 31. |
- Sandberg Melin, Camilla, et al.
(author)
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Variance components for PIMD‐2π estimation of the optic nerve head and consequences in clinical measurements of glaucoma
- 2020
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In: Acta Ophthalmologica. - : John Wiley & Sons. - 1755-375X .- 1755-3768. ; 98:2, s. 190-194
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Journal article (peer-reviewed)abstract
- Purpose To estimate the sources of variation for Pigment epithelium central limit-Inner limit of the retina Minimal Distance averaged over 2 pi (PIMD-2 pi), and further to analyse their consequences for clinical measurements of glaucoma. Methods Forty subjects with early to moderate stage glaucoma were included. Three SD-OCT volumes of the optic nerve head (ONH) were captured at two occasions. Each volume was segmented three times for PIMD-2 pi. The magnitude of the sources of variation for PIMD-2 pi measurements was estimated with an analysis of variance. Results A 95% confidence interval for mean PIMD-2 pi was estimated to 215 +/- 12 mu m (df = 38). The estimated variance for subjects was 1280 mu m(2). The within-subject estimated variance for occasions, volumes and segmentations was 10 mu m(2), 30 mu m(2) and 40 mu m(2), respectively. The within-subject variances were used to model follow-up of PIMD-2 pi over time. A linear loss rate of 0.05 of baseline PIMD-2 pi/year was assumed. A significant PIMD-2 pi change could be detected in approximately 16-18 months with evenly spaced visits every 4 or 6 months. Conclusions Due to the small within-subject estimated variances, a clinically undesirable PIMD-2 pi change from baseline can be detected in approximately 18 months. Detection of significant PIMD-2 pi loss in a subject requires knowledge of normal age loss and measurement variability.
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| 32. |
- Sandberg Melin, Camilla, et al.
(author)
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Variance components in confocal scanning laser tomography measurements of neuro-retinal rim area and the effect of repeated measurements on the power to detect loss over time
- 2016
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In: Acta Ophthalmologica. - : Wiley. - 1755-375X .- 1755-3768. ; 94:7, s. 705-711
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Journal article (peer-reviewed)abstract
- PurposeTo estimate the variation in measurements of neuro-retinal rim area (NRA) determined by confocal scanning laser tomography and consequences for clinical follow-up. MethodsAltogether, 24 healthy subjects were randomized on -320m, Moorfields and Standard NRA plane strategies. Additionally, NRA was measured in 32 glaucoma subjects. Variance components for subjects, visits and measurements were estimated with analysis of variance. Sample sizes required to detect a 6.0x10(-2)mm(2) NRA change were estimated assuming a significance level of 0.05 and a power of 0.8. Consequences for independent group, and paired comparison design, respectively, were analysed. Further, precision in estimates within subjects over time was investigated. ResultsThe variation of NRA among subjects was considerably larger than the variation among visits and measurements. For glaucoma subjects, the variation among visits and measurements were of the same order but larger than in healthy subjects. It was found that independent group comparisons require inconveniently large sample sizes. Within-subject paired comparisons over time require sample sizes of below 15 subjects. The estimated variations for glaucoma subjects imply that 54months of follow-up is required for detection of change from baseline. ConclusionsThe variance for subjects is substantial in relation to those for visits and measurements. Cross-sectional independent group comparisons of levels of NRA are unsuitable, due to considerable subject variation. Levels of NRA differences within subjects between visits can be estimated with acceptable precision. Neuro-retinal rim area (NRA) measurement can be used for long-term follow-up of glaucoma progression.
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| 33. |
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| 34. |
- Sundström, Johan, Professor, 1971-, et al.
(author)
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Rationale for a Swedish cohort consortium
- 2019
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In: Upsala Journal of Medical Sciences. - : Taylor & Francis Group. - 0300-9734 .- 2000-1967. ; 124:1, s. 21-28
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Journal article (peer-reviewed)abstract
- We herein outline the rationale for a Swedish cohort consortium, aiming to facilitate greater use of Swedish cohorts for world-class research. Coordination of all Swedish prospective population-based cohorts in a common infrastructure would enable more precise research findings and facilitate research on rare exposures and outcomes, leading to better utilization of study participants' data, better return of funders' investments, and higher benefit to patients and populations. We motivate the proposed infrastructure partly by lessons learned from a pilot study encompassing data from 21 cohorts. We envisage a standing Swedish cohort consortium that would drive development of epidemiological research methods and strengthen the Swedish as well as international epidemiological competence, community, and competitiveness.
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| 35. |
- Söderberg, Per, 1956-, et al.
(author)
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Does infrared or ultraviolet light damage the lens?
- 2016
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In: Eye (London. 1987). - : Springer Science and Business Media LLC. - 0950-222X .- 1476-5454. ; 30:2, s. 241-246
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Journal article (peer-reviewed)abstract
- In daylight, the human eye is exposed to long wavelength ultraviolet radiation (UVR), visible radiation and short wavelength infrared radiation (IRR). Almost all the UVR and a fraction of the IRR waveband, respectively, left over after attenuation in the cornea, is absorbed in the lens. The time delay between exposure and onset of biological response in the lens varies from immediate-to-short-to-late. After exposure to sunlight or artificial sources, generating irradiances of the same order of magnitude or slightly higher, biological damage may occur photochemically or thermally. Epidemiological studies suggest a dose-dependent association between short wavelength UVR and cortical cataract. Experimental data infer that repeated daily in vivo exposures to short wavelength UVR generate photochemically induced damage in the lens, and that short delay onset cataract after UVR exposure is photochemically induced. Epidemiology suggests that daily high-intensity short wavelength IRR exposure of workers, is associated with a higher prevalence of age-related cataract. It cannot be excluded that this effect is owing to a thermally induced higher denaturation rate. Recent experimental data rule out a photochemical effect of 1090 nm in the lens but other wavelengths in the near IRR should be investigated.
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| 36. |
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| 37. |
- Söderberg, Per G., 1956-, et al.
(author)
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Angular distribution of Pigment epithelium central limit-Inner limit of the retina Minimal Distance (PIMD), in the young not pathological optic nerve head imaged by OCT
- 2018
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In: OPHTHALMIC TECHNOLOGIES XXVIII. - : SPIE-INT SOC OPTICAL ENGINEERING. - 9781510614345 - 9781510614338 ; 10474, s. 38:1-38:7
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Conference paper (peer-reviewed)abstract
- The present study aimed to elucidate the angular distribution of the Pigment epithelium central limit-Inner limit of the retina Minimal Distance measured over 2 pi radians in the frontal plane (PIMD-2 pi) in young healthy eyes. Both healthy eyes of 16 subjects aged [20; 30[years were included. In each eye, a volume of the optical nerve head (ONH) was captured three times with a TOPCON DRI OCT Triton (Japan). Each volume renders a representation of the ONH 2.8 mm along the sagittal axis resolved in 993 steps, 6 mm long the frontal axis resolved in 512 steps and 6 x mm along the longitudinal axis resolved in 256 steps. The captured volumes were transferred to a custom made software for semiautomatic segmentation of PIMD around the circumference of the ONH. The phases of iterated volumes were calibrated with cross correlation. It was found that PIMD-2 pi expresses a double hump with a small maximum superiorly, a larger maximum inferiorly, and minima in between. The measurements indicated that there is no difference of PIMD-2 pi between genders nor between dominant and not dominant eye within subject. The variation between eyes within subject is of the same order as the variation among subjects. The variation among volumes within eye is substantially lower.
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| 38. |
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| 39. |
- Söderberg, Per, 1956-, et al.
(author)
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Katarakt - : ett optiskt problem i ögats lins
- 2016
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In: Läkartidningen. - 0023-7205 .- 1652-7518. ; 113, s. 1532-1536
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Journal article (peer-reviewed)abstract
- Katarakt definieras som nedsatt syn på grund av en optisk störning i ögats lins.Cirka 50 procent av kataraktsjukdomen antas associerad med genetiska faktorer.Ultraviolett strålning är epidemiologiskt starkt associerad med barkkatarakt, och rökning med kärnkatarakt.Störning av proteinkoncentrationsgradienten i linsen orsakar ljusspridning.Kemiska förändringar i linsens vattenlösliga proteiner kan orsaka aggregation av dessa.Betydande teknisk utveckling inom kataraktkirurgi reflekteras i en linjär ökning av antalet kataraktoperationer i Sverige under de senaste 35 åren.I snö och vid vatten bör solglasögon av filterkategori 3 användas för att skydda ögonen.
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| 40. |
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| 41. |
- Söderberg, Per, 1956-, et al.
(author)
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Optic nerve head morphometry for glaucoma diagnosis, optimization of clinical measurement strategy
- 2019
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In: Proceedings of SPIE. - : SPIE. - 0277-786X. ; 10858, s. 45:1-45:8
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Journal article (peer-reviewed)abstract
- The present study aimed to develop a strategy for evaluation of instant PIMD-2 pi measurements as a basis for clinical monitoring of glaucoma. PIMD-2 pi is a morphometric measure of the waist of the nerve fiber layer at the optic nerve head (ONH). Clinical measurements of PIMD-2 pi in patients with early to moderate stage glaucoma demonstrated a high variability among subjects. The high variability among subjects renders comparison of instant PIMD-2 pi measurements to tolerance limits for normality derived from a normative database inefficient. It is suggested to instead compare sequential measurements of PIMD-2 pi within a patient. Initially, the difference between an instant measurement and the average of previous measurements can be compared to tolerance limits for difference between measurements within subject. Once, a potential loss of PIMD-2 pi is detected, a sufficient number of measurements within a sufficiently wide time interval can be used to estimate the PIMD-2 pi loss rate with regression and the deviation of the estimated loss rate can be evaluated as a 95 % confidence interval for the loss rate. If the upper confidence limit excludes 0, a significant loss rate has been detected. The currently proposed strategy has the potential to detect glaucoma earlier than the current gold standard, computer perimetry, with less inconvenience for the patient.
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| 42. |
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| 43. |
- Talebizadeh, Nooshin, 1977-, et al.
(author)
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Objective automated quantification of fluorescence signal in histological sections of rat lens
- 2017
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In: Cytometry Part A. - : Wiley. - 1552-4922 .- 1552-4930. ; 91:8, s. 815-821
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Journal article (peer-reviewed)abstract
- Visual quantification and classification of fluorescent signals is the gold standard in microscopy. The purpose of this study was to develop an automated method to delineate cells and to quantify expression of fluorescent signal of biomarkers in each nucleus and cytoplasm of lens epithelial cells in a histological section. A region of interest representing the lens epithelium was manually demarcated in each input image. Thereafter, individual cell nuclei within the region of interest were automatically delineated based on watershed segmentation and thresholding with an algorithm developed in Matlab™. Fluorescence signal was quantified within nuclei, cytoplasms and juxtaposed backgrounds. The classification of cells as labelled or not labelled was based on comparison of the fluorescence signal within cells with local background. The classification rule was thereafter optimized as compared with visual classification of a limited dataset. The performance of the automated classification was evaluated by asking 11 independent blinded observers to classify all cells (n = 395) in one lens image. Time consumed by the automatic algorithm and visual classification of cells was recorded. On an average, 77% of the cells were correctly classified as compared with the majority vote of the visual observers. The average agreement among visual observers was 83%. However, variation among visual observers was high, and agreement between two visual observers was as low as 71% in the worst case. Automated classification was on average 10 times faster than visual scoring. The presented method enables objective and fast detection of lens epithelial cells and quantification of expression of fluorescent signal with an accuracy comparable with the variability among visual observers.
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| 44. |
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| 45. |
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| 46. |
- Zhou, Bin, et al.
(author)
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Worldwide trends in diabetes since 1980: A pooled analysis of 751 population-based studies with 4.4 million participants
- 2016
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In: The Lancet. - : Elsevier B.V.. - 0140-6736 .- 1474-547X. ; 387:10027, s. 1513-1530
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Journal article (peer-reviewed)abstract
- Background: One of the global targets for non-communicable diseases is to halt, by 2025, the rise in the age standardised adult prevalence of diabetes at its 2010 levels. We aimed to estimate worldwide trends in diabetes, how likely it is for countries to achieve the global target, and how changes in prevalence, together with population growth and ageing, are aff ecting the number of adults with diabetes.Methods: We pooled data from population-based studies that had collected data on diabetes through measurement of its biomarkers. We used a Bayesian hierarchical model to estimate trends in diabetes prevalence-defined as fasting plasma glucose of 7.0 mmol/L or higher, or history of diagnosis with diabetes, or use of insulin or oral hypoglycaemic drugs-in 200 countries and territories in 21 regions, by sex and from 1980 to 2014. We also calculated the posterior probability of meeting the global diabetes target if post-2000 trends continue.Findings: We used data from 751 studies including 4372000 adults from 146 of the 200 countries we make estimates for. Global age-standardised diabetes prevalence increased from 4.3% (95% credible interval 2.4-17.0) in 1980 to 9.0% (7.2-11.1) in 2014 in men, and from 5.0% (2.9-7.9) to 7.9% (6.4-9.7) in women. The number of adults with diabetes in the world increased from 108 million in 1980 to 422 million in 2014 (28.5% due to the rise in prevalence, 39.7% due to population growth and ageing, and 31.8% due to interaction of these two factors). Age-standardised adult diabetes prevalence in 2014 was lowest in northwestern Europe, and highest in Polynesia and Micronesia, at nearly 25%, followed by Melanesia and the Middle East and north Africa. Between 1980 and 2014 there was little change in age-standardised diabetes prevalence in adult women in continental western Europe, although crude prevalence rose because of ageing of the population. By contrast, age-standardised adult prevalence rose by 15 percentage points in men and women in Polynesia and Micronesia. In 2014, American Samoa had the highest national prevalence of diabetes (>30% in both sexes), with age-standardised adult prevalence also higher than 25% in some other islands in Polynesia and Micronesia. If post-2000 trends continue, the probability of meeting the global target of halting the rise in the prevalence of diabetes by 2025 at the 2010 level worldwide is lower than 1% for men and is 1% for women. Only nine countries for men and 29 countries for women, mostly in western Europe, have a 50% or higher probability of meeting the global target.Interpretation: Since 1980, age-standardised diabetes prevalence in adults has increased, or at best remained unchanged, in every country. Together with population growth and ageing, this rise has led to a near quadrupling of the number of adults with diabetes worldwide. The burden of diabetes, both in terms of prevalence and number of adults aff ected, has increased faster in low-income and middle-income countries than in high-income countries.
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