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Biomedical subjects

A Rydberg

Publications and source records attributed to A Rydberg.

At least 19 recordsLinked to original sources
PubMed2006

Evaluation of accommodative Insufficiency with the Visual Analogue Scale (VAS).

PURPOSE: The purpose of this study was to evaluate whether asthenopic symptoms in schoolchildren diagnosed with accommodative insufficiency (AI) and graded with the Visual Analogue Scale (VAS) could be correlated with the degree of accommodative deficiency in these children, and to investigate if VAS grading of the asthenopic symptoms could be used as an instrument to indicate the level of improvement of AI. METHODS: Forty-nine children (mean age 10.2 years +/- 2.7) diagnosed with AI graded their degree of asthenopia on the VAS before and after a 12-week treatment period wearing individually dispensed reading glasses. RESULTS: The improvement in accommodation after treatment was statistically significant (p < 0.001) and 83.7% of the children obtained normal accommodative amplitude in relation to age. The reduction in asthenopic symptoms as graded with the VAS was also statistically significant (p < 0.001) after treatment and 89.9% of the children obtained a normal VAS score. However, no correlation between the degree of accommodative deficiency and the VAS grading could be found, neither before nor after treatment. DISCUSSION: Based on these results we conclude that the visual analogue scale (VAS) cannot be used as an instrument to indicate the degree of accommodative deficiency nor can it be used to indicate the level of improvement during the course of treatment. However, the VAS can be used as an instrument to verify and document whether or not asthenopic symptoms are present, and therefore also to indicate when symptoms have been relieved.

Accommodation, Ocular↗
PubMed2006

Attitudes about dental care among parents whose children suffer from severe congenital heart disease: a case-control study.

OBJECTIVES: To examine attitudes and experiences of parents whose children have complex congenital heart disease (CHD) with respect to dental health information and advice, dental care, and service and to compare the results with data from an age- and gender-matched control group without any medical problems. SETTING: Faculty of Medicine (Paediatric Cardiology and Paediatric Dentistry), Umeå University, Umeå, Sweden. SAMPLE AND METHOD: Each group comprised parents of 33 children; the children's mean age was 9.4 years. All the cases and the controls resided in the county of Västerbotten, northern Sweden. Data were collected with a questionnaire with 20 joint questions to both groups and four additional questions to the CHD group. RESULTS: Of the 20 joint questions, significant differences were displayed in the following areas: the professional group that provided the parents with dental health information and advice (P < 0.01), attitudes to reception at the dental clinic, and experience of sedation before operative dental treatment (P < 0.05). Parents to 11 children with CHD who were patients at a specialist clinic for paediatric dentistry scored the reception at the dental clinic as excellent in nine cases and satisfactory in two, compared to excellent (3), satisfactory (11), decent (4), and poor (4) among those who were patients in general dental practice (P < 0.01). No statistically significant differences in educational level or in parental experience of dental health were noted between the two groups (P > 0.05). CONCLUSION: Children with CHD in northern Sweden mainly receive their dental health information from a physician or a dentist, and healthy children mainly receive information from a dental hygienist indicating that children with CHD are given priority in the dental care system. Parental attitudes to reception in the dental service differed, and parents of healthy children scored the reception at the dental clinic better than parents of children with CHD. It is suggested that children with severe CHD should receive dental care in clinics for paediatric dentistry, particularly at early ages.

Adolescent↗
PubMed2006

Contrast sensitivity in 10 year old preterm and full term children: a population based study.

AIMS: To determine the contrast sensitivity (CS) in 10 year old prematurely born children, previously included in a population based study on the incidence of retinopathy of prematurity (ROP), and in full term controls. METHODS: This study included 205 prematurely born children and 215 children born at term, from the same geographical area and study period. CS was assessed monocularly with the Vistech 6500 test at five spatial frequencies (1.5-18 cycles/deg). RESULTS: Prematurely born children had statistically significant lower CS at all frequencies, compared to full term ones. The mean differences in logarithmic CS were 0.03 (1.5 cycles/deg), 0.09 (3 cycles/deg), 0.10 (6 cycles/deg), 0.12 (12 cycles/deg), and 0.19 (18 cycles/deg). Even when the children with ROP and neurological disorders were excluded there was a difference between the two groups. Children who had been treated with cryotherapy had the lowest CS. CONCLUSION: CS was lower in 10 year old prematurely born children than in full term ones of the same age. Whether this finding affects their visual function in daily life is uncertain.

Child↗
PubMed2004

Dental caries experience in children with congenital heart disease: a case-control study.

OBJECTIVES: To compare the dental health of a group of children with complex congenital heart disease with that of age and gender matched healthy controls. DESIGN: Case-control study. SETTING: Faculty of Medicine and Odontology/Pediatric cardiology and Pedodontics, Umeå University, Sweden. SAMPLE AND METHODS: All the cases and their controls lived in the county of Västerbotten in northern Sweden. Each group comprised 41 children with a mean age of 6.5 years. Data were collected from medical and dental records while all bitewing radiographs were read separately by one of the authors. RESULTS: Children with congenital heart disease had significantly more caries in their primary teeth than the control group. The mean dmfs-value was 5.2 +/- 7.0 in the cardiac group compared to 2.2 +/- 3.5 in the control group (P < 0.05). Twenty-six of the children had all four 6-year-molars, and their mean DMFS-values were 0.9 +/- 1.9 in the cardiac group compared to 0.3 +/- 0.6 in the control group (P > 0.05). The children with congenital heart disease had received more caries prevention based on the use of fluorides than the control group. There was a significant correlation between the number of fluoride varnish treatments and the dmfs value of the child (r = 0.411, P < 0.01). Fifty-two per cent of the children in the cardiac group had been prescribed fluoride tablets on one or more occasions compared to 17% in the control group (P < 0.01). Number of months on digoxin medication and the dmfs-value had a significant correlation (r = 0.368, P < 0.05). Ten of the children had been on digoxin medication between 6 and 87 months; this subgroup had a mean dmfs-value of 10.1 +/- 8.5. CONCLUSION: Swedish children with complex congenital heart disease have poorer dental health than healthy age and gender matched controls in spite of intensive preventive efforts. In many cases, intervention had been given when caries were present. A closer cooperation between paediatric cardiology and paediatric dentistry is needed.

Cardiotonic Agents↗
PubMed2000

Electrocardiographic ST-segment depression in children with fontan circulation.

Despite successful operation, many patients palliated with a Fontan-type procedure continue to show effort limitation. We previously observed that these children showed electrocardiographic ST depression during exercise tests. The purpose of the study was to investigate whether electrocardiographic ST depression is a common finding in children with Fontan circulation. Forty-two children in two groups were examined: group A consisted of 14 patients who had all undergone a modified Fontan procedure, and group B consisted of 28 children with a structurally normal heart, matched for length, weight and gender to group A. Complete echocardiographic examinations were performed in all patients and controls. All 14 patients and all 28 healthy children underwent standard 24 h ambulatory electrocardiographic monitoring. All the recordings were analysed by a PC-based Holter system where an analysis of ST changes was performed. Seven patients and 14 matched healthy children were exercised on bicycle ergometers. Four patients and eight matched healthy children underwent exercise testing by walking/running a treadmill. Ten of 13 patients analysed had significant ST depressions on ambulatory electrocardiogram (>0.20 mV). Three of the 10 patients with ST depression were on digoxin. Three patients showed depressions of the ST segment in the electrocardiogram during exercise, with a maximal depression of 0.20-0.35 mV. None of the 28 matched healthy children showed electrocardiographic ST depression on the ambulatory 24 h ECG. These findings indicate that ST depression in daily activity is a common finding in children with Fontan circulation.

Adolescent↗
PubMed1999

Assessment of visual acuity in children aged 1 1/2-6 years, with normal and subnormal vision.

The aim of the study was to assess different visual acuity tests in the age group 1 1/2-6 years in 105 children with assumed normal vision, visual impairment due to ocular disease or strabismus. Acuity tasks for young children can be divided into three subtypes according to the kind of stimulus used. For "detection acuity", the stimulus should be detected or distinguished from the background, as assessed with the Stycar Rolling Balls. For "resolution acuity", the stimulus pattern should be resolved, as assessed with the Preferential Looking procedure (Teller Acuity Cards). For "recognition acuity", the stimulus must be recognized by the subject as assessed with the BUST-D symbol test, Sheridan Gardiner (S-G) single letters, LH single symbols and line tests, and also the HVOT test. Different acuity values were obtained with regard to detection, resolution and recognition acuities. Assessment with the Stycar Rolling Balls only gave a rough estimate of the visual function. There was an overestimation of the acuity values in all groups of children when using the Preferential Looking technique. Good agreement was found between the LH line and HVOT tests. The BUST-D test, S-G single letters, and LH single symbols gave slightly better acuity values than linear recognition tests. A "crowding ratio" was calculated by dividing the single optotype acuity by the linear acuity, and also by dividing the grating acuity by the optotype linear and single acuity. The crowding ratio varied in the individual children and in the different groups, being highest for strabismic amblyopia. The general conclusion is that reliable visual acuity measurements were not obtained until the visual acuity could be assessed with a recognition test using linear letters or symbols.

Adult↗
PubMed1999

Assessment of contrast sensitivity in children aged 3 years 9 months - 6 years with normal vision, visual impairment due to ocular disease and strabismic amblyopia.

The contrast sensitivity function was assessed in children and adults with normal vision, visual impairment due to ocular disease, and strabismic amblyopia. The methods used were: the LH contrast vision test and the ability to detect raisins, puffed rice and white and black sugar strands against a white and black background. The aim of the study was to see whether any of the tests could be used in the detection of subnormal vision, and to compare the results between the different groups of patients. The following parameters of contrast sensitivity function (CSF) were measured with the LH-test: the maximum contrast sensitivity, the total area of CSF, and the area of 8 spatial frequency bands. Difficulty in detecting an object with low versus high contrast was measured with the sugar strands. Subjects with subnormal vision due to ocular disease and strabismic amblyopia had lower contrast sensitivity than subjects with normal vision measured as the total area of the CSF or the area of a specific frequency band. However, the maximum contrast sensitivity value that could be measured with the test was not significantly different between the groups. No subject had difficulties in the detection of raisins and puffed rice on a white and black background. Difficulties in detecting sugar strands on a white background were not seen in the normal children, but approximately 65% of the children with visual impairment had difficulties, as did approximately 25% of the children and adults with strabismus. Most of these subjects also had low visual acuity, but there was no correlation between the level of reduction of visual acuity and the difficulty in detecting sugar strands.

Adult↗
PubMed1998

Pulmonary venous blood flow pattern in patients with univentricular hearts following total cavo-pulmonary connection.

The objective of the study was evaluation of the pulmonary venous blood flow (PVF) pattern and the influence of ventricular function and atrioventricular valve regurgitation on this flow in patients with univentricular hearts post total cavo-pulmonary connection (TCPC). Transthoracic or transoesophageal echocardiographic studies were performed in 24 children with normal hearts (group A) and in 24 patients with univentricular hearts (group B). Ventricular function and atrioventricular valve regurgitation was semiquantitatively assessed. Systolic/diastolic maximal velocities and velocity time integrals (VTI) were measured from PVF tracings. Ejection fraction was measured by radionuclide angiography in 11 patients. Twelve patients underwent heart catheterization and angiography. In group B the PVF showed a biphasic flow velocity curve. The systolic integrals were smaller and the diastolic integrals were larger than in group A (6.4 vs. 13.0 cm, P = 0.0001, and 13.9 vs. 10.0 cm, P = 0.005). The pulmonary venous systolic flow fraction in 13 patients with an open fenestration and/or atrioventricular valve regurgitation grade 2-3 was significantly lower than in those 11 patients without fenestration and none/small regurgitation (0.19 vs. 0.40, P = 0.05). In conclusion, the PVF pattern in children with univentricular hearts pallitated with TCPC is similar to the PVF pattern found in individuals with biventricular hearts showing a biphasic flow velocity curve despite the absence of pulsatile pulmonary artery flow. The PVF in patients with TCPC-palliated univentricular hearts is influenced by atrioventricular valve regurgitation and fenestration flow.

Adolescent↗
PubMed1998

Late fenestration closure in the hypoplastic left heart syndrome: comparison of hemodynamic changes.

BACKGROUND AND OBJECTIVES: Although survival of patients with the hypoplastic left heart syndrome treated by staged surgical palliation has improved, hemodynamic data after fenestrated Fontan operation and after fenestration closure have not been reported in this patient population. We sought to describe the hemodynamic status of these patients at cardiac catheterization performed for the purpose of fenestration closure and to compare these data with data from contemporary patients with other forms of univentricular heart. METHODS AND RESULTS: Hemodynamic responses to fenestration closure during cardiac catheterization were reviewed in 40 consecutive patients, including 20 with the hypoplastic left heart syndrome and 20 with other forms of univentricular heart defects. Hemodynamics before fenestration closure (arterial saturation and pressure, Fontan baffle saturation and pressure, pulmonary capillary wedge pressure, systemic arteriovenous oxygen content difference, and right-to-left shunt fraction) were nearly identical between the two groups. Significant (p < 0.05) changes after fenestration closure included increases in arterial saturation (9%), mean arterial pressure (3 mm Hg), and baffle pressure (1 mm Hg) and arteriovenous oxygen content difference (18 ml/L), with near elimination of right-to-left shunting. Cardiac output decreased by 21% and systemic oxygen transport by 13%, with no differences between the two patient groups. Mean baffle pressures were <17 mm Hg in 32 patients (80%). CONCLUSIONS: Hemodynamics after fenestrated Fontan operation and responses to fenestration closure in patients with the hypoplastic left heart syndrome were remarkably similar to that in patients with other univentricular heart defects.

Adolescent↗
PubMed1997

Reduced activity in the extrastriate visual cortex of individuals with strabismic amblyopia.

In order to examine the relationship between reduced visual acuity in human strabismic amblyopia and the cortical activation pattern, we studied, by use of positron emission tomography (PET) and the H2(15)O bolus technique, changes in the regional cerebral blood flow (rCBF) induced by monocular visual stimulation of 8 individuals with this disorder. Individual amblyopic thresholds for monocular detection of the checkerboard pattern were employed as stimuli for both eyes during PET scans. Statistical analysis of subtracted images showed significant increases in rCBF (P < 0.05) by the stimulation of the sound eye localized bilaterally to Brodmann's areas (BAs) 17-19. The cortical response evoked by the amblyopic eye was significantly reduced (P < 0.05) in the ipsilateral BAs 18, 19. These results suggest that the reduction in contrast sensitivity (pattern vision) in amblyopia is coupled with deactivation in identifiable regions of occipital visual areas, including ipsilateral BAs 18,19.

Adult↗
PubMed1997

Computer simulation of circulation in patient with total cavo-pulmonary connection: inter-relationship of cardiac and vascular pressure, flow, resistance and capacitance.

The aim is to develop a computer model representative of the circulation in a patient with a uni-ventricular heart surgically palliated by a total cavo-pulmonary connection (TCPC). The effects of known hazardous exposures on this type of circulation are investigated. A model of the cardiovascular system is built using standard components such as transmission lines, restrictors and capacitances. The chamber of the heart consists of a volume connected to checkvalves, and an oscillating source flow connected to the volume represents the pumping of the heart. The following are simulated: exposure to cold, heat, high altitude, accelerating forces, blood loss, reduction in ventricular function, atrioventricular-valve regurgitation and treatment with afterload-reducing agents. During simulations, all the parameters can be changed, independently of each other, and the resulting changes in flow, resistance and pressure are recorded. Exposure to cold, reduced ventricular function and atriventricular-valve regurgitation result in a decrease in cardiac output (14, 58 and 45%, respectively). At high altitude, an increase of 18% is noted in the central venous pressure. Afterload-reducing agents increase the cardiac output by 8% and reduce central aortic pressure by 23%. Blood loss results in a marked reduction in perfusion pressure. It is concluded that the computer model is a useful instrument for simulation of a TCPC or Fontan circulation. The original criteria for this surgical procedure are those showing the most marked haemodynamic responses to different stimulus.

Computer Simulation↗
PubMed1997

Assessment of visual acuity in adult patients with strabismic amblyopia: a comparison between the preferential looking method and different acuity charts.

PURPOSE: Grating acuity values obtained with preferential looking techniques do not correspond to test results obtained with letter charts. The aim of the study was to investigate the agreement between grating acuity and other acuity tests. METHODS: Twenty-eight adult patients with strabismic amblyopia were assessed with the preferential looking-method and other linear and single letter and symbol tests. RESULTS: Assessment with preferential looking regularly led to an overestimation of the acuity values, but between preferential looking and single optotypes there was a much better agreement. This is most likely due to 'crowding' in strabismic amblyopia. A crowding ratio was calculated in the amblyopic eye, and crowding was found to be more prominent for comparisons of preferential looking with optotypes in rows, than for preferential looking and single optotypes. CONCLUSIONS: Strabismic amblyopia cannot be reliably identified with grating acuity. Preferential looking-testing is therefore of limited use as a screening method for the detection of amblyopia, but preferential looking could still be useful in the assessment and treatment.

Adult↗
PubMed1996

Results of treatment of amblyopia with a screening program for early detection.

The Swedish program for early intervention in children with visual dysfunction, was evaluated with respect to the results of treatment of amblyopia. One hundred and seventy-two amblyopic children were examined before and at 6, 12 and 18 months after the beginning of treatment. The mean visual acuity of the amblyopic eye was 0.76 and the mean ratio of visual acuity between the two eyes was 0.75 or better in all types of amblyopia. Children with strabismic amblyopia showed slightly poorer treatment results than the other types, in spite of the fact that their amblyopia had been detected earlier than the others. The results attest to the importance of careful screening of monocular visual acuity in all children, which in Sweden occurs at 4 years of age. This provides a good basis for detection and treatment of amblyopia. Only one child in the group had a visual acuity at 0.2 and may therefore be at risk for visual handicap if the better eye should be lost later in life.

Amblyopia↗
PubMed1993

Visual functions in a Swedish population of dyslexic and normally reading children.

Eighty-six 9-year old dyslexic children were carefully matched to controls with regard to age, sex, class in school, and intelligence and thorough visual functions tests and eye examinations were performed. As a group the dyslexic pupils exhibited a lower distance as well as near visual acuity both with monocular and binocular viewing. Furthermore, the dyslexic pupils had a lower contrast sensitivity at the lower and higher spatial frequencies. These differences were all statistically significant. However, no statistically significant differences between the two groups could be observed regarding refractive errors or contrast sensitivity in the middle spatial frequency range. Although some eyes were amblyopic, any severe eye anomalies or diseases were not found in any of the investigated children.

Child↗
PubMed1993

Oculomotor functions in a Swedish population of dyslexic and normally reading children.

Eighty-six nine-year-old dyslexic children were matched to control children with regard to age, sex, class in school, and intelligence. Orthoptic and eye movement analysis were performed on all children. It was concluded that the dyslexic pupils did not differ significantly from control children in terms of strabismus, accommodation, stereo acuity, vergence function or ocular dominance. Eye movement recordings did not show any qualitative differences between the groups in vergence dynamics during synoptophore investigations.

Accommodation, Ocular↗
PubMed1987

Changes in neck muscles in Swedish reindeer bucks during rutting season.

Three neck muscles in Swedish reindeer bucks have been studied before and during the rutting season. These were M. splenius, M. sternocephalicus and M. brachiocephalicus. For comparison, M. longissimus dorsi was chosen. Fibre composition and fibre size were studied in the four muscles as also was the metabolic potential of three enzymes, representing respiratory chain (cytochrome oxidase), beta-oxidation of fatty acids (3-hydroxyacyl-CoA dehydrogenase) and anaerobic glycolysis (lactate dehydrogenase). The extreme increase in size of certain muscles in the neck in connection with the rutting season (e.g. sternocephalicus, which increases from 250 g to 1,500 g) was to a great extent due to an increase in fibre size. In splenius, all three fibre types studied increased (I, IIA, IIB); in brachiocephalicus, mainly IIA and IIB; and in sternocephalicus, only the IIB. No corresponding fibre increase could be found in longissimus dorsi. In splenius and sternocephalicus from bucks older than 54 months, 60-70% of the fibres were of type I, and in brachiocephalicus, only about 40%. In all muscles but one, oxidative capacity (cytochrome oxidase) and beta-oxidation of fatty acids (3-hydroxyacyl-CoA dehydrogenase) decreased significantly during the rutting season. This indicates that purposes other than the enhancement of energy production by fatty acid oxidation must account for the enlargement of the neck muscles.

3-Hydroxyacyl CoA Dehydrogenases↗
PubMed1984

Amblyopia screening in kindergartens with tno stereotest.

One hundred and fifty children between 3 and 6 years old were screened for amblyopia with TNO stereotest in their kindergartens. Thirty screening positive children were found of whom 3 were amblyopic with strabismus and no stereopsis. Re-testing showed that 19 children were false screening positive. Three children with refractive errors and equally impaired vision in both eyes were not detected. The test was found suitable for screening of monocular amblyopia in kindergartens, as it was easy to administrate and indicated all children with monocular amblyopia.

Amblyopia↗