1
|
Ventus D, Söderberg P. Are In-the-Moment Resilience Processes Predicted by Questionnaire-Based Measures of Resilience? Assessment 2024:10731911241234220. [PMID: 38456257 DOI: 10.1177/10731911241234220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/09/2024]
Abstract
Research on resilience is a growing field, and resilience has been conceptualized and operationalized in multiple ways. The aim of this study was to compare the Brief Resilient Coping Scale (BRCS), a conventional measure of resilience, with within-person process indicators derived from experience sampling method (ESM). A sample of 177 teachers from southern Finland participated in the study, commencing with a startup session followed by an 8-day ESM period. Through twice-daily prompts, participants reported their immediate positive and negative affect as well as recent stressors encountered, such as workload and challenging social interactions. As expected, within-person variation in affect was predicted by stressors. However, contrary to expectations, individual differences in affective reactivity to stressors were not predicted by BRCS (βpositive affect [95% CI] = -.20, [-.51, .11]; βnegative affect = .33, [-.07, .69]). Item response theory analyses of the BRCS revealed problems with precision. The results call into question the validity of measuring resilience using single administrations of retrospective self-report questionnaires such as the BRCS.
Collapse
|
2
|
Mölsä ME, Forsman AK, Söderberg P. Associations between interpersonal contexts, positive emotions, and related experiences in school students: A systematic review of experience sampling studies. Sch Psychol 2023:2024-20890-001. [PMID: 37902704 DOI: 10.1037/spq0000587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2023]
Abstract
Studies investigating students' social interactions and related experiences have mostly relied on retrospective methodologies-techniques known to be subject to recall bias that threaten ecological validity. This article is the second part of a systematic review of experience sampling studies on students' social interactions. This article focuses on exploring associations between interpersonal contexts, positive emotions, and related experiences assessed by intensive repeated measurement techniques in naturalistic environments. A systematic literature search was conducted for experience sampling studies between 1996 and 2020. Details of the literature search process and results were reported in the companion (Part I) of the study (Mölsä et al., 2022; Frontiers in Psychology 2022; 13: 844698). Using a narrative synthesis, the associations of interpersonal contexts and positive emotionality in school students were analyzed. Findings suggest that school students experience higher levels of positive emotions during peer, teacher, and family interactions than when they are not being with someone. The overall findings indicate that positive emotionality in children and adolescents is dependent on the characteristics of the interpersonal contexts, although the multilevel associations vary. This review contributes to experience sampling research on students' social interactions. The systematic review concludes with discussion of the main findings, theoretical implications, and an analysis of limitations. (PsycInfo Database Record (c) 2023 APA, all rights reserved).
Collapse
Affiliation(s)
- Martina E Mölsä
- Department of Developmental Psychology, Faculty of Education and Welfare Studies, Abo Akademi University
| | - Anna K Forsman
- Department of Health Sciences, Faculty of Education and Welfare Studies, Abo Akademi University
| | - Patrik Söderberg
- Department of Developmental Psychology, Faculty of Education and Welfare Studies, Abo Akademi University
| |
Collapse
|
3
|
Mölsä ME, Lax M, Korhonen J, Gumpel TP, Söderberg P. The Experience Sampling Method in Monitoring Social Interactions Among Children and Adolescents in School: A Systematic Literature Review. Front Psychol 2022; 13:844698. [PMID: 35444596 PMCID: PMC9013852 DOI: 10.3389/fpsyg.2022.844698] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Accepted: 03/11/2022] [Indexed: 11/16/2022] Open
Abstract
Background The experience sampling method (ESM) is an increasingly popular data collection method to assess interpersonal dynamics in everyday life and emotions contextualized in real-world settings. As primary advantages of ESM sampling strategies include minimization of memory biases, maximization of ecological validity, and hypothesis testing at the between- and within-person levels, ESM is suggested to be appropriate for studying the daily lives of educational actors. However, ESM appears to be underutilized in education research. We, thus, aimed to systematically evaluate the methodological characteristics and quality of published ESM studies of social interactions among children and adolescents in school settings, as well as to explore how much variance in social interaction variables could be attributed to the within-person level. Method Using Academic Search Complete, APA PsycINFO, APA PsycArticles, ProQuest, Web of Science, Wiley Online Library, and SAGE Journals, and in accordance with PRISMA guidelines and pre-defined eligibility criteria, we conducted a systematic literature search of experience sampling studies up to November 2020. To assess methodological quality, we used a modified checklist for reporting of ESM studies. Results Of the originally 2 413 identified studies, a final 52 experience sampling studies were included in the present review. Findings on sample and study design characteristics generally revealed wide variability. Even if high-quality studies were associated with higher scores on the training of participants in using the ESM procedure, and use of incentives, these design strategies did not reveal a statistically significant impact on compliance. The intraclass correlation coefficient was reported in nine studies and on average 58% of the variance in social interaction variables could be attributed to within-person fluctuation between timepoints. Conclusion The current study is the first to systematically review ESM-based studies on social interactions among children and adolescents in the school context. These observations suggest that ESM is a potentially favorable technique for extracting complex social phenomena in real-world settings. We hope that this review will contribute to improving the quality assessment of ESM studies as well as to inform and guide future experience sampling studies, particularly regarding social phenomena with children and adolescents in educational settings.
Collapse
Affiliation(s)
- Martina E Mölsä
- Department of Developmental Psychology, Faculty of Education and Welfare Studies, Åbo Akademi University, Vaasa, Finland
| | - Mikael Lax
- Department of Developmental Psychology, Faculty of Education and Welfare Studies, Åbo Akademi University, Vaasa, Finland
| | - Johan Korhonen
- Department of Developmental Psychology, Faculty of Education and Welfare Studies, Åbo Akademi University, Vaasa, Finland
| | - Thomas P Gumpel
- School of Education, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Patrik Söderberg
- Department of Developmental Psychology, Faculty of Education and Welfare Studies, Åbo Akademi University, Vaasa, Finland
| |
Collapse
|
4
|
Backman-Nord P, Söderberg P, Forsman AK. The happiest youth in the world? Exploring subjective well-being indicators among Finnish university students. Nordic Psychology 2021. [DOI: 10.1080/19012276.2021.1996264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Pia Backman-Nord
- Department of Developmental Psychology/Faculty of Education and Welfare Studies, Åbo Akademi University, Vasa, Finland
| | - Patrik Söderberg
- Department of Developmental Psychology/Faculty of Education and Welfare Studies, Åbo Akademi University, Vasa, Finland
| | - Anna. K. Forsman
- Department of Health Sciences/Faculty of Education and Welfare Studies, Åbo Akademi University, Vasa, Finland
| |
Collapse
|
5
|
Grigaitytė I, Söderberg P. Why does perceived social support protect against somatic symptoms: Investigating the roles of emotional self-efficacy and depressive symptoms? Nordic Psychology 2021. [DOI: 10.1080/19012276.2021.1902845] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
|
6
|
Söderberg P, Korhonen J, Björkqvist K. Psychosocial Maladjustment at Student and Classroom Level as Indicators of Peer Victimization. Violence Vict 2017; 32:842-857. [PMID: 28810942 DOI: 10.1891/0886-6708.vv-d-15-00166] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The purpose of this study was to examine the role of aggressive behavior, anxiety, and peer rejection as multilevel indicators of peer victimization. A cross-sectional sample of 1,115 Finnish 9th grade students nested in 76 classrooms (mean age 15 years) were used to conduct multilevel models. All forms of psychosocial maladjustment, as well as student family economy, were found to predict peer victimization within classrooms. In addition, classrooms with more aggressive behavior and a higher proportion of rejected students suffered more peer victimization, beyond compositional effects of aggressive and rejected students being victimized.
Collapse
|
7
|
Söderberg P, Wanhainen A, Svensjö S. Five Year Natural History of Screening Detected Sub-Aneurysms and Abdominal Aortic Aneurysms in 70 Year Old Women and Systematic Review of Repair Rate in Women. J Vasc Surg 2017. [DOI: 10.1016/j.jvs.2017.05.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
8
|
Söderberg P, Wanhainen A, Svensjö S. Five Year Natural History of Screening Detected Sub-Aneurysms and Abdominal Aortic Aneurysms in 70 Year Old Women and Systematic Review of Repair Rate in Women. Eur J Vasc Endovasc Surg 2017; 53:802-809. [DOI: 10.1016/j.ejvs.2017.02.024] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Accepted: 02/21/2017] [Indexed: 11/30/2022]
|
9
|
Talebizadeh N, Yu Z, Kronschläger M, Galichanin K, Söderberg P. Evidence for apoptosis in the lens after in vivo
exposure to ultraviolet radiation. Acta Ophthalmol 2016. [DOI: 10.1111/j.1755-3768.2016.0126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
10
|
Sandberg Melin C, Malmberg F, Söderberg P. Clinical precision for follow-up of glaucoma with PIMD-2 Pi. Acta Ophthalmol 2016. [DOI: 10.1111/j.1755-3768.2016.0415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
11
|
Galichanin K, Yu Z, Talebizadeh N, Burmakin M, Söderberg P. Exposure to subthreshold dose of UVR-B induces apoptosis in the lens epithelial cells and does not in the lens fiber cells. Acta Ophthalmol 2016. [DOI: 10.1111/j.1755-3768.2016.0288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
12
|
Yu Z, Schulmeister K, Talebizadeh N, Kronschläger M, Söderberg P. Is the increasing exposure of the eye to near-infrared radiation from remote controls and sensing a threat to the lens? Acta Ophthalmol 2016. [DOI: 10.1111/j.1755-3768.2016.0040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
13
|
Yu Z, Schulmeister K, Talebizadeh N, Kronschläger M, Söderberg P. Thermal cataract induced by near infrared radiation (IRR). Acta Ophthalmol 2015. [DOI: 10.1111/j.1755-3768.2015.0416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Z. Yu
- Neuroscience/Ophthalmology; Gullstrand LAB; Uppsala Sweden
| | - K. Schulmeister
- Laser-LED & Lampen-Sicherheit; Seibersdorf Labor GmbH; Seibersdorf Austria
| | - N. Talebizadeh
- Neuroscience/Ophthalmology; Gullstrand LAB; Uppsala Sweden
| | | | - P. Söderberg
- Neuroscience/Ophthalmology; Gullstrand LAB; Uppsala Sweden
| |
Collapse
|
14
|
Kronschläger M, Yu Z, Talebizadeh N, Söderberg P. Caffeine, an in vivo oxidation protectant in the lens. Acta Ophthalmol 2015. [DOI: 10.1111/j.1755-3768.2015.0036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
| | - Z. Yu
- Ophthalmology; Uppsala University; Uppsala Sweden
| | | | - P. Söderberg
- Ophthalmology; Uppsala University; Uppsala Sweden
| |
Collapse
|
15
|
Sandberg Melin C, Malmberg F, Malmqvist L, Talebizadeh N, Yu Z, Söderberg P. Pigment epithelium central limit - Inner limit of the retina, Minimal Distance, PIMD, a morphometrical variable for glaucoma follow-up. Acta Ophthalmol 2015. [DOI: 10.1111/j.1755-3768.2015.0304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Affiliation(s)
- C. Sandberg Melin
- Gullstrand Lab-Opthalmology; Neuroscience; Uppsala University; Uppsala Sweden
- Region Gavleborg; Uppsala University; Gävle Sweden
| | - F. Malmberg
- Information Technology; Uppsala University; Uppsala Sweden
| | - L. Malmqvist
- Gullstrand Lab-Opthalmology; Neuroscience; Uppsala University; Uppsala Sweden
| | - N. Talebizadeh
- Gullstrand Lab-Opthalmology; Neuroscience; Uppsala University; Uppsala Sweden
| | - Z. Yu
- Gullstrand Lab-Opthalmology; Neuroscience; Uppsala University; Uppsala Sweden
| | - P. Söderberg
- Gullstrand Lab-Opthalmology; Neuroscience; Uppsala University; Uppsala Sweden
| |
Collapse
|
16
|
Affiliation(s)
- Douglas P. Fry
- Peace, Mediation and Conflict Research, Åbo Akademi University in Vasa, Post Office Box 311, FIN-65101, Vasa, Finland
- Bureau of Applied Research in Anthropology, School of Anthropology, Post Office Box 210030, Tucson, AZ 85721–0030, USA
| | - Patrik Söderberg
- Peace, Mediation and Conflict Research, Åbo Akademi University in Vasa, Post Office Box 311, FIN-65101, Vasa, Finland
- Developmental Psychology, Åbo Akademi University in Vasa, Post Office Box 311, FIN-65101, Vasa, Finland
| |
Collapse
|
17
|
Barle H, Söderberg P, Haegerstrand C, Markström A. Bi-level positive airway pressure ventilation reduces the oxygen cost of breathing in long-standing post-polio patients on invasive home mechanical ventilation. Acta Anaesthesiol Scand 2005; 49:197-202. [PMID: 15715621 DOI: 10.1111/j.1399-6576.2004.00566.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Today, patients with chronic respiratory failure are commonly treated with non-invasive bi-level positive airway pressure ventilation, supporting spontaneous breathing. However, in conformity with previous clinical routine, many post-polio patients with chronic respiratory failure are still treated with invasive (i.e. via a tracheostomy) controlled mechanical ventilation (CMV). The aim of the study was to investigate the effect of invasive bi-level positive airway pressure ventilation on the work of breathing compared with that during the patients' ordinary CMV and spontaneous breathing without mechanical support. METHODS Nine post-polio patients on invasive (tracheostomy) nocturnal CMV were investigated. Work of breathing was analysed by assessing differences in oxygen consumption (VO2) using indirect calorimetry. Hereby, the oxygen cost of breathing during the various ventilatory modes could be estimated and related to one another. Data on energy expenditure were also obtained. RESULTS The oxygen cost of breathing decreased by approximately 15% during bi-level positive airway pressure ventilation compared with CMV and spontaneous breathing. There was no difference between predicted (Harris-Benedict equation) and measured energy expenditure. CONCLUSION Invasive bi-level positive airway pressure ventilation reduces the oxygen cost of breathing in long-standing tracheostomized post-polio patients, compared with CMV. Furthermore, the Harris-Benedict equation provides a reasonable prediction of energy expenditure in this group of patients.
Collapse
Affiliation(s)
- H Barle
- Department of Anesthesiology/Intensive Care, Karolinska Institutet, Danderyd Hospital, Stockholm, Sweden.
| | | | | | | |
Collapse
|
18
|
Abstract
PURPOSE To develop a universal standard for comparison of the results from different studies using Scheimpflug photography. MATERIAL AND METHOD A suspension including polystyrene spheres was selected as the universal standard. The polystyrene suspension was diluted into 10 concentrations by adding spectroscopic quality water. An artificial eye chamber was designed to hold the diluted suspension for photography. Each concentration was photographed by both a Topcon SL-45 slit-lamp camera and a Nidek EAS-1000 system. The intensity of back-scattered light was analyzed statistically. RESULTS The relationship between the concentration of the polystyrene suspension and the internal gray scale step within the Topcon SL-45 camera can be described by a second-order polynomial. The relationship between the concentration of the polystyrene suspension and the measurement of the Nidek EAS-1000 system can also be expressed by a second-order polynomial. The relationship between the Topcon SL-45 camera and the Nidek EAS-1000 system is linear. CONCLUSIONS The results of lens nuclear opacity measured with different Scheimpflug cameras can be compared using the method established in the study. The linear relationship between the Topcon SL-45 and Nidek EAS-1000 systems can be used to convert measurements from one system to the other.
Collapse
Affiliation(s)
- W Qian
- Research Laboratory, St. Erik's Eye Hospital, Karolinska Institutet, Stockholm, Sweden.
| | | | | | | |
Collapse
|
19
|
Merriam JC, Löfgren S, Michael R, Söderberg P, Dillon J, Zheng L, Ayala M. An action spectrum for UV-B radiation and the rat lens. Invest Ophthalmol Vis Sci 2000; 41:2642-7. [PMID: 10937577] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023] Open
Abstract
PURPOSE To determine an action spectrum for UV-B radiation and the rat lens and to show the effect of the atmosphere and the cornea on the action spectrum. METHODS One eye of young female rats was exposed to 5-nm bandwidths of UV-B radiation (290, 295, 300, 305, 310, and 315 nm). Light scattering of exposed and nonexposed lenses was measured 1 week after irradiation. A quadratic polynomial was fit to the dose-response curve for each wave band. The dose at each wave band that produced a level of light scattering greater than 95% of the nonexposed lenses was defined as the maximum acceptable dose (MAD). Transmittance of the rat cornea was measured with a fiberoptic spectrophotometer. The times to be exposed to the MAD in Stockholm (59.3 degrees N) and La Palma (28 degrees N) were compared. RESULTS Significant light scattering was detected after UV-B at 295, 300, 305, 310, and 315 nm. The lens was most sensitive to UV-B at 300 nm. Correcting for corneal transmittance showed that the rat lens is at least as sensitive to UV radiation at 295 nm as at 300 nm. The times to be exposed to the MAD at each wave band were greater in Stockholm than in La Palma, and in both locations the theoretical time to be exposed to the MAD was least at 305 nm. CONCLUSIONS After correcting for corneal transmittance, the biological sensitivity of the rat lens to UV-B is at least as great at 295 nm as at 300 nm. After correcting for transmittance by the atmosphere, UV-B at 305 nm is the most likely wave band to injure the rat lens in both Stockholm and La Palma.
Collapse
Affiliation(s)
- J C Merriam
- St. Erik's Eye Hospital, Karolinska Institutet, Stockholm, Sweden.
| | | | | | | | | | | | | |
Collapse
|
20
|
Frisk P, Hagberg H, Mandahl A, Söderberg P, Lönnerholm G. Cataracts after autologous bone marrow transplantation in children. Acta Paediatr 2000; 89:814-9. [PMID: 10943964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
We recorded the incidence and degree of posterior subcapsular cataract (PSC) in 29 children who had undergone autologous (n = 28) or syngeneic (n = 1) bone marrow transplantation (BMT) due to haematologic or lymphoid malignancy. Conditioning prior to transplantation consisted either of a combination of chemotherapy and total body irradiation (TBI) (n = 21) or of chemotherapy only (n = 8). TBI was given in one fraction of 7.5 Gy. Nine patients had received previous cranial irradiation. The patients were followed for 4-10y (median 8 y) after transplantation. Of 29 patients, 22 developed PSC, all within 4 y after BMT. With the exception of one patient who developed unilateral PSC, all had received TBI. Conversely, 100% of those who received TBI developed PSC. In this group (+TBI), eight patients (38%) developed significant PSC, defined as best corrected visual acuity <0.8 in either eye. Six patients (10 eyes) have since needed surgical repair consisting of extracapsular cataract extraction and intraocular lens implantation. There was no clear relationship between previous cranial irradiation and cataract development, nor any other obvious baseline differences between those in the +TBI group who developed significant PSC and those who did not. Although effects of previous therapy cannot be ruled out, TBI appears to be the main cause of PSC in this group of patients. Twelve patients in the +TBI group had well-preserved visual acuity throughout the study, reflecting a slow progression of PSC. This compares favourably with previous reports of allogeneic BMT, possibly owing to less need for corticosteroids after autologous BMT. We conclude that the incidence of PSC was high after autologous BMT where the conditioning regimen included total body irradiation.
Collapse
Affiliation(s)
- P Frisk
- Uppsala University Children's Hospital, Sweden
| | | | | | | | | |
Collapse
|
21
|
Manns F, Rol P, Parel JM, Schmid A, Shen JH, Matsui T, Söderberg P. Optical profilometry of poly(methylmethacrylate) surfaces after reshaping with a scanning photorefractive keratectomy (SPRK) system. Appl Opt 1996; 35:3338-3346. [PMID: 21102720] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
A prototype frequency-quintupled Nd:YAG laser was used with a scanning system to create, on poly(methylmethacrylate) (PMMA) blocks, ablations corresponding to a correction of 6 diopters of myopia by photorefractive keratectomy. The topography of the ablated samples was measured with an optical profilometer to evaluate the smoothness and accuracy of the ablations. The ablation depth was larger than expected. With a 50% to 70% spot overlap, large valleylike variations with a maximum peak-to-peak amplitude of 20 µm were observed. With an 80% spot overlap, the rms surface roughness was 1.3 µm, and the central flattening was 7 diopters. This study shows that optical profilometry can be used to determine precisely the ablation per pulse and the smoothness and accuracy of surface ablations. Knowing the exact ablation per pulse is necessary to produce a smooth and accurate corneal surface by scanning photorefractive keratectomy.
Collapse
|
22
|
Manns F, Shen JH, Söderberg P, Matsui T, Parel JM. Development of an algorithm for corneal reshaping with a scanning laser beam. Appl Opt 1995; 34:4600-4608. [PMID: 21052292 DOI: 10.1364/ao.34.004600] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The corneal-ablation rate, the beam-intensity distribution, and the initial and the desired corneal topographies are used to calculate a spatial distribution map of laser pulses. The optimal values of the parameters are determined with a computer model, for a system that produces 213-nm radiation with a Gaussian beam-intensity distribution and a peak radiant exposure of 400 mJ/cm(2). The model shows that with a beam diameter of 0.5 mm, an overlap of 80%, and a 5-mm treatment zone, the roughness is less than 6% of the central ablation depth, the refractive error after correction is less than 0.1 D for corrections of myopia of 1, 3, and 6 D and less than 0.4 D for a correction of myopia of 10 D, and the number of pulses per diopter of correction is 2500 when the beam-intensity distribution is Gaussian and 580 when it is flat.
Collapse
|
23
|
Qian W, Söderberg P, Lindström B, Chen E, Magnius K, Philipson B. Spatial distribution of back scattering in the nuclear area of the non-cataractous human lens. Eye (Lond) 1994; 8 ( Pt 5):524-9. [PMID: 7835446 DOI: 10.1038/eye.1994.130] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
The spatial distribution of back scattering from a vertical cross-section of the nuclear area in non-cataractous human lens was investigated. The cross-section was centred on the pupil. There is no significant difference in average nuclear back scattering between sides. The distribution of back scattering along an axis perpendicular to the anatomical axis can be modelled as a second-order polynomial. It is believed that the increase of back scattering in the central region corresponds to the peak protein concentration in the centre of the nucleus. This information was obtained by imaging back scattering with Scheimpflug photography. The back scattering was measured photometrically in a 3 x 10 matrix of measuring areas within the lens nucleus. Each measuring area was 0.20 x 0.20 mm in size. It is anticipated that the established model will allow detection of nuclear cataract with high sensitivity, especially in early stages.
Collapse
Affiliation(s)
- W Qian
- Research Laboratory, St. Erik's Eye Hospital, Stockholm, Sweden
| | | | | | | | | | | |
Collapse
|
24
|
Tengroth B, Fagerholm P, Söderberg P, Hamberg-Nyström H, Epstein D. Effect of Corticosteroids in Postoperative Care Following Photorefractive Keratectomies. J Refract Surg 1993. [DOI: 10.3928/1081-597x-19930302-17] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
25
|
Tengroth B, Fagerholm P, Söderberg P, Hamberg-Nyström H, Epstein D. Effect of corticosteroids in postoperative care following photorefractive keratectomies. Refract Corneal Surg 1993; 9:S61-4. [PMID: 8499381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Since the start of photorefractive keratectomy (PRK) Seiler has recommended the use of topical corticosteroids during the first 3 months after surgery. The rationale for this treatment was to diminish the inflammatory reaction as well as to control the keratocytes from producing collagen and creating scars. Our knowledge of corneal wound healing in general, and after PRK in particular, is very limited and the action of corticosteroids is still unclear. Corticosteroids, when given in comparatively large topical doses, create problems. Between 15 and 30% of patients are corticosteroid responders with increased intraocular pressure. This is a threat to the eye, and also a burden for the doctor as intraocular pressure has to be checked during the treatment. The risk for cataract formation after longer periods of topically administered corticosteroids also has been discussed. In order to decrease the rise in intraocular pressure, FML has been used in place of dexamethasone. During the 4 years follow up after PRK it has been reported that a number of patients do not regress or get a scar formation if they have not used corticosteroids in the postoperative period. The reasons to avoid topical corticosteroids in some patients are a misunderstanding of their instructions, or those who have had a history of herpes infection or glaucoma. A double-masked study of the effects of corticosteroids after PRK was performed by Gartry, et al in a small group of patients. After 6 months, the results revealed that there were no differences between the corticosteroid and the non-corticosteroid group. However, the standard deviation was high.(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
Affiliation(s)
- B Tengroth
- St Eriks Eye Hospital, Karolinska Institute, Stockholm, Sweden
| | | | | | | | | |
Collapse
|
26
|
|