| 1. |
- Andersson-Engels, Stefan, et al.
(author)
-
Integrated system for interstitial photodynamic therapy
- 2003
-
In: Proceedings of SPIE - The International Society for Optical Engineering. - : SPIE. - 0277-786X .- 1996-756X. ; 5142, s. 42-49
-
Conference paper (peer-reviewed)abstract
- A novel photodynamic therapy system based on interstitial illumination using multiple fibres is under development. The aim with this system is to enable treatment of large tumour volumes and also to utilise real-time measurements to allow on-line dosimetry. Important dosimetric parameters to measure are light fluence rate, sensitizer fluorescence intensity and local blood oxygenation. A construction which allows all functions to be readily performed with a single system is presented. We believe that interstitial PDT utilising this technique may be attractive in many clinical situations.
|
|
| 2. |
- Andersson-Engels, Stefan, et al.
(author)
-
Integrated system for interstitial photodynamic therapy
- 2002
-
In: Advanced Optical Devices, Technologies, and Medical Applications. - : SPIE. - 0277-786X .- 1996-756X. ; 5123, s. 293-302
-
Conference paper (peer-reviewed)abstract
- To develop PDT beyond treatment of thin superficial tumours, to also be an efficient treatment alternative for deeply located and/or thick tumours, a system based on interstitial illumination using multiple fibres has been developed. Conditions that could benefit from such a treatment modality are for instance malignant brain tumours and tumours in the oral cavity. In interstitial PDT one needs to use multiple fibres for light delivery in order to allow treatments of tumours larger than a few millimetres in diameter. Our system consists of a laser light source, a beam-splitting system dividing the light into three or six output fibres and a custom-made dosimetry programme. The concept is then to use these fibres not only for delivering the treatment light but also to measure parameters of interest for the treatment outcome. The fluence rate of the light emitted by each fibre is measured at the positions of the other fibre tips. From these results the light dose at all positions could be recalculated. Changes in optical properties as well as bleaching and concentration of the photosensitizer during the treatment could be monitored and compensated for in the dosimetry. Tumours have been treated both in experimental studies and in patients with thick superficial Basal Cell Carcinomas. Almost all treated skin lesions responded with complete response.
|
|
| 3. |
- Bystricky, Lukas, et al.
(author)
-
An accurate integral equation method for Stokes flow with piecewise smooth boundaries
-
Other publication (other academic/artistic)abstract
- Two-dimensional Stokes flow through a periodic channel is considered. The channel walls need only be Lipschitz continuous, in other words they are allowed to have corners. Boundary integral methods are an attractive numerical method to solve the Stokes equations, as the problem can be reformulated into a problem that must be solved only over the boundary of the domain. When the boundary is at least C1 smooth, the boundary integral kernel is a compact operator, and traditional Nyström methods can be used to obtain highly accurate solutions. In the case of Lipschitz continuous boundaries however, obtaining accurate solutions using the standard Nyström method can require high resolution. We adapt a technique known as recursively compressed inverse preconditioning to accurately solve the Stokes equations without requiring any more resolution than is needed to resolve the boundary. Combined with a periodic fast summation method we construct a method that is O(N log N ) where N is the number of quadrature points on the boundary. We demonstrate the robustness of this method by extending an existing boundary integral method for viscous drops to handle the movement of drops near corners.
|
|
| 4. |
- Bystricky, Lukas, et al.
(author)
-
An accurate integral equation method for Stokes flow with piecewise smooth boundaries
- 2020
-
In: BIT Numerical Mathematics. - : Springer. - 0006-3835 .- 1572-9125.
-
Journal article (peer-reviewed)abstract
- Two-dimensional Stokes flow through a periodic channel is considered. The channel walls need only be Lipschitz continuous, in other words they are allowed to have corners. Boundary integral methods are an attractive tool for numerically solving the Stokes equations, as the partial differential equation can be reformulated into an integral equation that must be solved only over the boundary of the domain. When the boundary is at least C1 smooth, the boundary integral kernel is a compact operator, and traditional Nyström methods can be used to obtain highly accurate solutions. In the case of Lipschitz continuous boundaries, however, obtaining accurate solutions using the standard Nyström method can require high resolution. We adapt a technique known as recursively compressed inverse preconditioning to accurately solve the Stokes equations without requiring any more resolution than is needed to resolve the boundary. Combined with a periodic fast summation method we construct a method that is O(Nlog N) where N is the number of quadrature points on the boundary. We demonstrate the robustness of this method by extending an existing boundary integral method for viscous drops to handle the movement of drops near corners.
|
|
| 5. |
- Carlert, Sara, et al.
(author)
-
Predicting intestinal precipitation : a case example for a basic BCS class II drug
- 2010
-
In: Pharmaceutical research. - : Springer Science and Business Media LLC. - 0724-8741 .- 1573-904X. ; 27:10, s. 2119-2130
-
Journal article (peer-reviewed)abstract
- PURPOSE: To investigate the prediction accuracy of in vitro and in vitro/in silico methods for in vivo intestinal precipitation of basic BCS class II drugs in humans. METHODS: Precipitation rate of a model drug substance, AZD0865 (pKa = 6.1; log K(D) = 4.2), was investigated in vitro using simulated intestinal media, and calculations of the crystallization rates were made with a theoretical model. Human intestinal precipitation was estimated by analysis of pharmacokinetic data from clinical studies at different doses. RESULTS: All in vitro models predicted rapid drug precipitation, where the intestinal concentration of dissolved AZD0865 at the highest dose tested was expected to decrease to half after less than 20 min. However, there was no indication of precipitation in vivo in humans as there was a dose proportional increase in drug plasma exposure. The theoretical model predicted no significant precipitation within the range of expected in vivo intestinal concentrations. CONCLUSIONS: This study indicated that simple in vitro methods of in vivo precipitation of orally administered bases overpredict the intestinal crystalline precipitation in vivo in humans. Hydrodynamic conditions were identified as one important factor that needs to be better addressed in future in vivo predictive methods.
|
|
| 6. |
- deWeert, Michael J., et al.
(author)
-
Analysis of spatial variability in hyperspectral imagery of the uterine cervix in vivo
- 2003
-
In: Proceedings of SPIE. - : SPIE. ; 4959, s. 67-76
-
Journal article (peer-reviewed)abstract
- The use of fluorescence and reflectance spectroscopy in the analysis of cervical histopathology is a growing field of research. The majority of this research is performed with point-like probes. Typically, clinicians select probe sites visually, collecting a handful of spectral samples. An exception to this methodology is the Hyperspectral Diagnostic Imaging (HSDI®) instrument developed by Science and Technology International. This non-invasive device collects contiguous hyperspectral images across the entire cervical portio. The high spatial and spectral resolution of the HSDI instruments make them uniquely well suited for addressing the issues of coupled spatial and spectral variability of tissues in vivo. Analysis of HSDI data indicates that tissue spectra vary from point to point, even within histopathologically homogeneous regions. This spectral variability exhibits both random and patterned components, implying that point monitoring may be susceptible to significant sources of noise and clutter inherent in the tissue. We have analyzed HSDI images from clinical CIN (cervical intraepithelial neoplasia) patients to quantify the spatial variability of fluorescence and reflectance spectra. This analysis shows the spatial structure of images to be fractal in nature, in both intensity and spectrum. These fractal tissue textures will limit the performance of any point-monitoring technology.
|
|
| 7. |
|
|
| 8. |
- Fryklund, Fredrik, 1988-, et al.
(author)
-
An integral equation method for the advection-diffusion equation on time-dependent domains in the plane
- 2023
-
In: Journal of Computational Physics. - : Elsevier BV. - 0021-9991 .- 1090-2716. ; 475
-
Journal article (peer-reviewed)abstract
- Boundary integral methods are attractive for solving homogeneous elliptic partial differen-tial equations on complex geometries, since they can offer accurate solutions with a com-putational cost that is linear or close to linear in the number of discretization points on the boundary of the domain. However, these numerical methods are not straightforward to ap-ply to time-dependent equations, which often arise in science and engineering. We address this problem with an integral equation-based solver for the advection-diffusion equation on moving and deforming geometries in two space dimensions. In this method, an adap-tive high-order accurate time-stepping scheme based on semi-implicit spectral deferred correction is applied. One time-step then involves solving a sequence of non-homogeneous modified Helmholtz equations, a method known as elliptic marching. Our solution method-ology utilizes several recently developed methods, including special purpose quadrature, a function extension technique and a spectral Ewald method for the modified Helmholtz kernel. Special care is also taken to handle the time-dependent geometries. The numerical method is tested through several numerical examples to demonstrate robustness, flexibility and accuracy.
|
|
| 9. |
- Gustafsson, U, et al.
(author)
-
Compact fiber-optic fluorosensor using a continuous-wave violet diode laser and an integrated spectrometer
- 2000
-
In: Review of Scientific Instruments. - : AIP Publishing. - 1089-7623 .- 0034-6748. ; 71:8, s. 3004-3006
-
Journal article (peer-reviewed)abstract
- A compact fluorosensor with a fiber-optic measurement probe was developed, employing a continuous-wave violet diode laser as an exciting source and an integrated digital spectrometer for the monitoring of fluorescence signatures. The system has the dimensions 22x13x8 cm(3), and features 5 nm spectral resolution and an excellent detectivity. Results from measurements on vegetation and human premalignant skin lesions are reported, illustrating the potential of the instrument. (C) 2000 American Institute of Physics. [S0034-6748(00)04508-1].
|
|
| 10. |
|
|
| 11. |
|
|
| 12. |
|
|
| 13. |
- Jakobsson, Joel, et al.
(author)
-
Monocyte and microglial activation in patients with mood-stabilized bipolar disorder.
- 2015
-
In: Journal of psychiatry & neuroscience : JPN. - : CMA Joule Inc.. - 1488-2434 .- 1180-4882. ; 40:2
-
Journal article (peer-reviewed)abstract
- Bipolar disorder is associated with medical comorbidities that have been linked to systemic inflammatory mechanisms. There is, however, limited evidence supporting a role of neuroinflammation in bipolar disorder. Here we tested whether microglial activation and associated tissue remodelling processes are related to bipolar disorder by analyzing markers in cerebrospinal fluid (CSF) and serum from patients and healthy controls.
|
|
| 14. |
- Johansson, Ann, et al.
(author)
-
Compact fiber-optic fluorosensor using high-power continuous-wave violet diode laser
- 2003
-
In: Proceedings of SPIE - The International Society for Optical Engineering. - : SPIE. - 0277-786X .- 1996-756X. ; 5141, s. 47-57
-
Conference paper (peer-reviewed)abstract
- In this work a compact fluorosensor has been built for point-monitoring and imaging applications. The instrument has been applied in fluorescence studies on green vegetation and on malignant tissue. The instrument is based on a violet diode laser, an integrated spectrometer and optical fibers for light delivery and collection of the fluorescence signal. This combination makes the system very compact. The high laser output power allows for coupling of the laser light into a hyperspectral diagnostic imaging instrument, developed and built by Science and Technology International. In point-monitoring mode, the instrument has been tested on superficial skin tumors and when using δ-aminolevulinic acid induced protoporphyrin IX as a tumor sensitizer, good contrast between normal and malignant tissue was achieved, clearly demonstrating its feasibility in cancer diagnostics. In imaging mode, the instrument functioned solely as a light source, coupling the excitation light into the hyperspectral imaging instrument. The set-up was tested by studying chlorophyll fluorescence from vegetation. The fluorescence signal showed a low signal-to-noise ratio mainly because of inefficient light coupling into the imaging instrument.
|
|
| 15. |
|
|
| 16. |
|
|
| 17. |
- Pålsson, Sara, et al.
(author)
-
Adaptive time-stepping for surfactant-laden drops
- 2017
-
In: Proceedings of the Eleventh UK Conference on Boundary Integral Methods (UKBIM 11). - 9780993111297 - 9781912253005
-
Conference paper (peer-reviewed)abstract
- An adaptive time-stepping scheme is presented aimed at computing the dynamics of surfactant-covered deforming droplets. This involves solving a coupled system, where one equation corresponds to the evolution of the drop interfaces and one to the surfactant concentration. The first is discretised in space using a boundary integral formulation which can be treated explicitly in time. The latter is a convection-diffusion equation solved with a spectral method and is advantageously solved with a semi-implicit method in time. The scheme is adaptive with respect to drop deformation as well as surfactant concentration and the adjustment of time-steps takes both errors into account. It is applied and demonstrated for simulation of the deformation of surfactant-covered droplets, but can easily be applied to any system of equations with similar structure. Tests are performed for both 2D and 3D formulations and the scheme is shown to meet set error tolerances in an efficient way.
|
|
| 18. |
- Pålsson, Sara, et al.
(author)
-
An integral equation method for closely interacting surfactant-covered droplets in wall-confined Stokes flow
-
Other publication (other academic/artistic)abstract
- A highly accurate method for simulating surfactant-covered droplets in two-dimensional Stokes flow with solid boundaries is presented. The method handles both periodic channel flows of arbitrary shape and stationary solid constrictions. A boundary integral method together with a special quadrature scheme is applied to solve the Stokes equations to high accuracy, also for droplets in close interaction. The problem is considered in a periodic setting and Ewald decompositions for the Stokeslet and stresslet are derived to make the periodic sums convergent. Computations are sped up using the spectral Ewald method. The time evolution is handled with a fourth order, adaptive, implicit-explicit time-stepping scheme. The numerical method is tested through several convergence studies and other challenging examples and is shown to handle drops in close proximity both to other drops and solid objects to a high accuracy.
|
|
| 19. |
- Pålsson, Sara, et al.
(author)
-
An integral equation method for closely interacting surfactant-covered droplets in wall-confined Stokes flow
- 2020
-
In: International Journal for Numerical Methods in Fluids. - : John Wiley and Sons Ltd. - 0271-2091 .- 1097-0363.
-
Journal article (peer-reviewed)abstract
- A highly accurate method for simulating surfactant-covered droplets in two-dimensional Stokes flow with solid boundaries is presented. The method handles both periodic channel flows of arbitrary shape and stationary solid constrictions. A boundary integral method together with a special quadrature scheme is applied to solve the Stokes equations to high accuracy, also for closely interacting droplets. The problem is considered in a periodic setting and Ewald decompositions for the Stokeslet and stresslet are derived. Computations are accelerated using the spectral Ewald method. The time evolution is handled with a fourth-order, adaptive, implicit-explicit time-stepping scheme. The numerical method is tested through several convergence studies and other challenging examples and is shown to handle drops in close proximity both to other drops and solid objects to high accuracy.
|
|
| 20. |
- Pålsson, Sara
(author)
-
Boundary integral methods for fast and accurate simulation of droplets in two-dimensional Stokes flow
- 2019
-
Doctoral thesis (other academic/artistic)abstract
- Accurate simulation of viscous fluid flows with deforming droplets creates a number of challenges. This thesis identifies these principal challenges and develops a numerical methodology to overcome them. Two-dimensional viscosity-dominated fluid flows are exclusively considered in this work. Such flows find many applications, for example, within the large and growing field of microfluidics; accurate numerical simulation is of paramount importance for understanding and exploiting them.A boundary integral method is presented which enables the simulation of droplets and solids with a very high fidelity. The novelty of this method is in its ability to accurately handle close interactions of drops, and of drops and solid boundaries, including boundaries with sharp corners. The boundary integral method is coupled with a spectral method to solve a PDE for the time-dependent concentration of surfactants on each of the droplet interfaces. Surfactants are molecules that change the surface tension and are therefore highly influential in the types of flow problems which are considered herein.A method’s usefulness is not dictated by accuracy alone. It is also necessary that the proposed method is computationally efficient. To this end, the spectral Ewald method has been adapted and applied. This yields solutions with computational cost O(N log N ), instead of O(N^2), for N source and target points.Together, these innovations form a highly accurate, computationally efficient means of dealing with complex flow problems. A theoretical validation procedure has been developed which confirms the accuracy of the method.
|
|
| 21. |
- Pålsson, Sara, et al.
(author)
-
Cataract surgery in patients with uveitis : Data from the Swedish National Cataract Register
- 2023
-
In: Acta Ophthalmologica. - : John Wiley & Sons. - 1755-375X .- 1755-3768. ; 101:4, s. 376-383
-
Journal article (peer-reviewed)abstract
- PURPOSE: To investigate the surgical and pharmacological management and outcomes of patients with cataract and concurrent uveitis.METHODS: Data from the Swedish National Cataract Register, 2018-2019, were collected and analysed. Uveitic eyes were identified and eyes without uveitis were used as controls. Generalized estimating equations were used to adjust for intra-individual correlation.RESULTS: The study included 719 eyes with and 256 360 without uveitis. The mean age was 66.0 ± 13.5 (standard deviation [SD]) years in the uveitis group and 74.3 ± 8.7 years in the control group (p < 0.001). Surgery was associated with more intraoperative difficulties in eyes with uveitis (27.0%) than in control eyes (7.1%; p < 0.001). Posterior capsule rupture/zonular complications were registered in nine eyes with uveitis (1.3%) and in 1464 eyes without uveitis (0.6%; p = 0.02). Hydrophilic acrylic intraocular lenses (uveitis 3.6%, controls 1.2%) and subconjunctival steroids (uveitis 17.4%, controls 6.1%) were more frequently used in eyes with uveitis (p < 0.001). post-operative best-corrected visual acuity (BCVA) was 0.16 ± 0.38 logarithm of the minimum angle of resolution (logMAR, mean ± SD) in eyes with uveitis (n = 52) and 0.08 ± 0.20 in control eyes (n = 14 489; p = 0.008).CONCLUSION: In this large registry-based Swedish cohort study, the findings demonstrate that cataract surgery in patients with uveitis poses more challenges and requires special surgical precautions. Eyes with concurrent uveitis had worse BCVA prior to and following surgery. Despite the intraoperative challenges, the visual improvement was greater in the uveitic group.
|
|
| 22. |
- Pålsson, Sara, et al.
(author)
-
Combined phacoemulsification, primary intraocular lens implantation, and pars plana vitrectomy in children with uveitis
- 2015
-
In: Ocular immunology and inflammation. - : Taylor & Francis. - 0927-3948 .- 1744-5078. ; 23:2, s. 144-151
-
Journal article (peer-reviewed)abstract
- PURPOSE: To evaluate the outcome of combined cataract surgery with primary intraocular lens (IOL) implantation and pars plana vitrectomy (PPV) in children with uveitis.METHODS: Data regarding visual acuity (VA), inflammatory status, medical therapy, and complications was collected from the medical charts of 17 children (21 eyes) with chronic uveitis who underwent combined cataract surgery and PPV at the Eye Clinic, Sahlgrenska/Mölndal, between 2002 and 2011.RESULTS: Seventy-six percent of the children had juvenile idiopathic arthritis. Median preoperative VA was 1.70 logMAR and median VA after 12 months was 0.17 logMAR. Postoperatively, glaucoma developed in 7 eyes, cystoid macular edema in 3 eyes, and visual axis opacification requiring treatment in 5 eyes.CONCLUSIONS: Although combined phacoemulsification, primary IOL implantation, and PPV in children with uveitis resulted in favorable visual outcome and stable inflammation in a majority of children, the technique should so far be reserved for uveitic cases with vitreous pathology.
|
|
| 23. |
|
|
| 24. |
|
|
| 25. |
|
|
| 26. |
|
|
| 27. |
- Pålsson, Sara, et al.
(author)
-
Methods for detailed histopathological investigation and localization of biopsies from cervix uteri to improve the interpretation of auto fluorescence data
- 2006
-
In: Journal of Environmental Pathology and Toxicology. - 2162-6537. ; 25:1-2, s. 321-340
-
Journal article (peer-reviewed)abstract
- Fluorescence spectroscopy is one of many optical methods that are potentially clinically useful for noninvasive detection and characterization of disorders on the cervical part of uterus, including precancerous lesions. The cervix uteri exhibits a biologically complex tissue and the morphology of a biopsy is generally not homogenous. The standard histopathological protocol accounts only for the most severe condition found within the biopsy and no information is given on other constituents potentially influencing the recorded fluorescence spectra. Spectra are usually correlated, using multivariate techniques, to the histopathological diagnosis of the biopsies. Since the probe volume of fluorescence spectroscopy is considerably smaller than the extension of the biopsy, this can cause problems in the search for correlation between the fluorescence signals and the pathological structures. In addition, the orientation and location of the biopsies are normally not recorded. We now report on the first detailed histopathological protocol where numerous tissue parameters, such as thickness and type of the epithelium and the number of blood vessels, glands, and inflammatory cells, are tabulated and the orientation and location of the biopsy are recorded as precisely as possible. Hopefully, the use of this protocol together with sophisticated mathematical methods will increase the probability to classify cervical disorders of the uterus, including precancerous lesions, with high sensitivity and specificity.
|
|
| 28. |
- Pålsson, Sara
(author)
-
Methods, Instrumentation and Mechanisms for Optical Characterization of Tissue and Treatment of Malignant Tumours
- 2003
-
Doctoral thesis (other academic/artistic)abstract
- In this thesis, different optical methods utilising visible light for characterization of tissue have been developed and evaluated. The feasibility of many of these methods has been demonstrated in the laboratory or in animal experiments. However, the goal is naturally to develop methods useful in the clinic, and thus the emphasis in this thesis has been put on in vivo examinations. Raman spectroscopy is an optical method that can provide information regarding vibrational modes in molecules and concentrations of tissue constituents. The Raman spectra contain sharp peaks and are suited for multivariate evaluation since one specific peak represents a vibrational mode that can be present in many different molecules. The Raman signal is weak and is often hidden in the strong fluorescence emission from tissue. The main challenge lies in the development of clinical Raman spectroscopy systems that are capable of recording Raman spectra with high resolution and low noise in a short accumulation time. This problem is discussed together with applications of Raman spectroscopy in cardiology and dermatology. Fluorescence spectroscopy is another technique used for tissue characterization and detection of lesions. The application of fluorescence spectroscopy for the delineation of borders between normal and malignant tissue in oncological dermatology and neurosurgery is discussed as well as the potential of classification of myocardial biopsies from patients with transplanted hearts. The construction and usefulness of a small clinical system is also discussed. In the development of models capable of correlating fluorescence spectra with clinical diagnosis, the problem of biopsy location and biological variability within the biopsies has been addressed in a study of protocols for histopathological evaluation in the field of gynaecology. The use of light for treatment of malignant tumours is often associated with the thermal impact of laser ‘knifes’ employed during excisions. However, light can also be a constituent in non-thermal photochemical reactions where light, together with a tumour-seeking photosensitizer and tissue oxygen, react and lead to critical cell death, which kills tumours. This treatment modality is called photodynamic therapy and some of the involved mechanisms have been explored in the thesis. Due to the limited penetration of visible light, a system for interstitial delivery of treatment light has been developed to be able to treat thicker and deeply located tumours. The dosimetry is important and the photodynamic threshold dose has been estimated.
|
|
| 29. |
- Pålsson, Sara
(author)
-
On cataract surgery in uveitis - management and outcome in pediatric and adult patients
- 2022
-
Doctoral thesis (other academic/artistic)abstract
- Aims: To evaluate surgical procedures and outcomes in cataract surgery in adults and children with uveitis. To compare the results of implantation of two different intraocular lenses (IOLs). Methods: Retrospective reviews of medical charts of children and adults with cataract and uveitis were performed (papers I and II). A randomized controlled trial to compare a hydrophobic and a hydrophilic IOL was conducted (paper III). Data from the National Cataract Register was analyzed (paper IV). Results: Paper I: In total, 21 pediatric eyes, treated with phacoemulsification, primary IOL implantation and pars plana vitrectomy, were included. Best corrected visual acuity (BCVA) improved in all except one eye. Glaucoma was the most common postoperative complication. Paper II: Altogether 58 uveitic eyes were included. Mechanical pupil dilation was more commonly needed in eyes with uveitis. Poor improvement in visual acuity was related to posterior segment abnormalities. Paper III: The study included 52 eyes with and 38 eyes without uveitis. Mechanical pupil dilation was more frequently used in eyes with uveitis. Flare measurements were higher in patients with uveitis, but no significant difference in flare or cystoid macular edema (CME) postoperatively related to IOL type was seen. Paper IV: Core registrations included 719 eyes with uveitis; 52 uveitic eyes were included in registrations of surgical outcome. Difficulties, e.g., with mechanical pupil dilation, capsular staining, and hooks at the rhexis margin, were more common in eyes with uveitis as well as posterior capsule rupture/zonulolysis. Oral steroids as well as subconjunctival steroids were more frequently used in uveitis. Improvement in BCVA was slightly better in uveitic eyes. Conclusion: This thesis demonstrates that challenges remain in cataract surgery in uveitis. Despite more challenging surgery and intraoperative difficulties, patients with uveitis showed satisfactory improvement in visual acuity. We did not find support for either hydrophilic or hydrophobic IOLs being advantageous over the other. Children with uveitis constitute a group with particular difficulties.
|
|
| 30. |
- Pålsson, Sara, et al.
(author)
-
Phacoemulsification with primary implantation of an intraocular lens in patients with uveitis
- 2017
-
In: Clinical Ophthalmology. - : Informa UK Limited. - 1177-5483. ; 11, s. 1549-1555
-
Journal article (peer-reviewed)abstract
- Purpose: To evaluate the outcome of cataract surgery in adult patients with uveitis. Materials and methods: In this retrospective cohort study, medical charts of patients with uveitis and matched control patients without uveitis who underwent cataract surgery at the Eye Clinic, Sahlgrenska University Hospital, Molndal, between January 2005 and December 2009 were analyzed. Results: The study included 58 eyes with and 283 eyes without uveitis. The most common etiologies were idiopathic anterior uveitis and Fuchs' heterochromic uveitis. Postoperative visual acuity at 4 weeks was >= 0.5 decimal (0.3 logMAR) in 48 eyes with uveitis (87.3%) compared to 180 non-uveitic eyes (86.1%). Four eyes with uveitis (7.1%) and one eye without uveitis (0.5%) developed postoperative intraocular hypertension/glaucoma. Posterior capsule opacification developed in 11 eyes (19.0%) with and 28 eyes (12.4%) without uveitis. Conclusion: With appropriate perioperative anti-inflammatory regimen and surveillance, modern cataract surgery using phacoemulsification and primary intraocular lens implantation can be performed in patients with uveitis without greater risk of complications, yielding similar visual outcome as in patients without uveitis.
|
|
| 31. |
- Pålsson, Sara, et al.
(author)
-
Phacoemulsification with primary implantation of an intraocular lens in patients with uveitis
- 2017
-
In: Clinical Ophthalmology. - : Dove Medical Press Ltd.. - 1177-5467 .- 1177-5483. ; 11, s. 1549-1555
-
Journal article (peer-reviewed)abstract
- PURPOSE: To evaluate the outcome of cataract surgery in adult patients with uveitis.MATERIALS AND METHODS: In this retrospective cohort study, medical charts of patients with uveitis and matched control patients without uveitis who underwent cataract surgery at the Eye Clinic, Sahlgrenska University Hospital, Mölndal, between January 2005 and December 2009 were analyzed.RESULTS: The study included 58 eyes with and 283 eyes without uveitis. The most common etiologies were idiopathic anterior uveitis and Fuchs' heterochromic uveitis. Postoperative visual acuity at 4 weeks was ≥0.5 decimal (0.3 logMAR) in 48 eyes with uveitis (87.3%) compared to 180 non-uveitic eyes (86.1%). Four eyes with uveitis (7.1%) and one eye without uveitis (0.5%) developed postoperative intraocular hypertension/glaucoma. Posterior capsule opacification developed in 11 eyes (19.0%) with and 28 eyes (12.4%) without uveitis.CONCLUSION: With appropriate perioperative anti-inflammatory regimen and surveillance, modern cataract surgery using phacoemulsification and primary intraocular lens implantation can be performed in patients with uveitis without greater risk of complications, yielding similar visual outcome as in patients without uveitis.
|
|
| 32. |
- Pålsson, Sara, et al.
(author)
-
Simulation and validation of surfactant-laden drops in two-dimensional Stokes flow
- 2019
-
In: Journal of Computational Physics. - : Academic Press. - 0021-9991 .- 1090-2716. ; 386, s. 218-247
-
Journal article (peer-reviewed)abstract
- Performing highly accurate simulations of droplet systems is a challenging problem. This is primarily due to the interface dynamics which is complicated further by the addition of surfactants. This paper presents a boundary integral method for computing the evolution of surfactant-covered droplets in 2D Stokes flow. The method has spectral accuracy in space and the adaptive time-stepping scheme allows for control of the temporal errors. Previously available semi-analytical solutions (based on conformal-mapping techniques) are extended to include surfactants, and a set of algorithms is introduced to detail their evaluation. These semi-analytical solutions are used to validate and assess the accuracy of the boundary integral method, and it is demonstrated that the presented method maintains its high accuracy even when droplets are in close proximity.
|
|
| 33. |
- Pålsson, Sara, et al.
(author)
-
Spectrally accurate Ewald summation for the Yukawa potential in two dimensions
-
Other publication (other academic/artistic)abstract
- An Ewald decomposition of the two-dimensional Yukawa potential and its derivative is presented for both the periodic and the free-space case. These modified Bessel functions of the second kind of zeroth and first degrees are used e.g. when solving the modified Helmholtz equation using a boundary integral method. The spectral Ewald method is used to compute arising sums at O(N log N ) cost for N source and target points. To facilitate parameter selection, truncation-error estimates are developed for both the real-space sum and the Fourier-space sum, and are shown to estimate the errors well.
|
|
| 34. |
- Soto Thompson, Marcelo, et al.
(author)
-
Photodynamic therapy and diagnostic measurements of basal cell carcinomas using esterified and non-esterified delta-aminolevulinic acid
- 2001
-
In: Journal of Porphyrins and Phthalocyanines. - 1099-1409. ; 5:2, s. 147-147
-
Journal article (peer-reviewed)abstract
- Various optical techniques were used to investigate relevant parameters involved in photodynamic therapy (PDT) of human basal cell carcinomas (BCCs). The aim of the study was to compare the diagnostic and therapeutic outcome when using topically applied methyl-esterified delta -aminolevulinic acid (ALA-ME) and delta -aminolevulinic acid (ALA). A total of 35 pathologically verified BCCs in 14 patients were investigated. A diode laser. emitting continuous light at 633 nm, was used to induce PDT. The diagnostic measurements were performed before, during, and after PDT. Laser-induced fluorescence (LIF) was used to monitor the build-up of the ALA/ALA-ME-induced protoporphyrin IX (PpIX), The superficial tissue perfusion was measured with laser-Doppler perfusion imaging (LDPI) and the temperature of the lesion and the surrounding tissue was imaged with an IR-camera. A clear demarcation between the lesion and the normal skin was detected with LIF before the treatment for both PpIX precursors. The fluorescence measurements suggest that PpIX builds up to a higher degree and more selectively in the tumour following ALA-ME as compared to ALA. The LDPI measurements indicate a local transient restriction in blood perfusion immediately post-PDT. The measurement with the IR-camera revealed a temperature rise of about 1-2 degreesC during the treatment.
|
|
| 35. |
- Soto Thompson, Marcelo, et al.
(author)
-
Photodynamic therapy of nodular basal cell carcinoma with multifiber contact light delivery
- 2006
-
In: Journal of Environmental Pathology and Toxicology. - 2162-6537. ; 25:1-2, s. 411-424
-
Journal article (peer-reviewed)abstract
- To overcome the limited treatment depth of superficial photodynamic therapy we investigate interstitial light delivery. In the present work the treatment light was delivered using a system in which three or six clear-cut fibers were placed in direct contact with the tumor area. This placement was thought to represent a step toward general purpose interstitial PDT. Twelve nodular basal cell carcinomas were treated employing delta-aminolevulinic acid and 635 nm laser irradiation. Fluorescence measurements were performed monitoring the buildup and subsequent bleaching of the produced sensitizer protoporphyrin IX. The treatment efficacy, judged at a 28-month follow-up, showed a 100% complete response. Two punch excisions at 7 months converted two partial responses to complete responses. One patient failed to appear at all follow-up sessions. The outcome of the treatments was comparable to superficial photodynamic therapy in terms of histological, clinical, and cosmetic results.
|
|
| 36. |
- Stenberg, M, et al.
(author)
-
Interstitial photodynamic therapy - diagnostic measurements and treatment in rat malignant experimental tumours
- 2000
-
In: OPTICAL BIOPSY AND TISSUE OPTICS. - : SPIE. - 1996-756X .- 0277-786X. - 0819438170 ; 4161:32, s. 151-157
-
Conference paper (peer-reviewed)abstract
- A recently developed multiple fibre system for treating malignant tumours with interstitial photodynamic therapy was used in studies on rats with colon adenocarcinoma inoculated into the muscles of the hind legs. The animals were intraperitonially administrated delta -aminolevulinic acid (ALA), which is metabolised to protoporphyrin IX (PpIX) in the tissue. The treatment system consists of a laser light source, a beam-splitting system dividing the light into three or six output fibres and a dosimetry programme calculating the optimal fibre position within the tumour as well as the treatment time needed to obtain a given threshold value of the light dose. One aim of the study was to compare the treatment outcome with the modelled dosimetry predictions. Tumour reduction was examined three days post treatment. A volume decrease was found in 85\% of the treated tumours. The mean volume reduction was 44\%, with one tumour completely disappearing. Histopathological examination three days post treatment showed substantial necrotic parts which, however, to a smaller extent were present also for non-treated tumours. These results indicated that the tumours have been under treated and the light dose has to be increased. Measurements of the build-up and photo-induced bleaching of PpIX using laser-induced fluorescence were also performed during the experiments.
|
|
| 37. |
- Swartling, Johannes, et al.
(author)
-
Changes in tissue optical properties due to radio-frequency ablation of myocardium
- 2003
-
In: Medical & Biological Engineering & Computing. - 0140-0118. ; 41:4, s. 403-409
-
Journal article (peer-reviewed)abstract
- The optical properties of pig heart tissue were measured after in vivo ablation therapy had been performed during open-heart surgery. In vitro samples of normal and ablated tissue were subjected to measurements with an optically integrating sphere set-up in the region 470-900nm. Three independent measurements were made: total transmittance, total reflectance and collimated transmittance, which made it possible to extract the absorption and scattering coefficients and the scattering anisotropy factor g, using an inverse Monte Carlo model. Between 470 and 700nm, only the reduced scattering coefficient and absorption could be evaluated. The absorption spectra were fitted to known tissue chromophore spectra, so that the concentrations of haemoglobin and myoglobin could be estimated. The reduced scattering coefficient was compared with Mie computations to provide Mie equivalent average radii. Most of the absorption was from myoglobin, whereas haemoglobin absorption was negligible. Metmyoglobin was formed in the ablated tissue, which could yield a spectral signature to distinguish the ablated tissue with a simple optical probe to monitor the ablation therapy. The reduced scattering coefficient increased by, on average, 50% in the ablated tissue, which corresponded to a slight decrease in the Mie equivalent radius.
|
|
