| 1. |
- Aring, Eva, 1959, et al.
(författare)
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Strabismus, binocular functions and ocular motility in children with hydrocephalus.
- 2007
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Ingår i: Strabismus. - : Informa UK Limited. - 0927-3972 .- 1744-5132. ; 15:2, s. 79-88
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: To investigate heterotropia, heterophoria, head posture, nystagmus, stereo acuity, ocular motility and near point of convergence (NPC) in children with hydrocephalus treated surgically before 1 year of age. In addition, the effects of being born with hydrocephalus, the effect of the etiology of hydrocephalus, number of shunt revisions and the size of the ventricles on these variables were studied. METHODS: A population-based study was performed in 75 children and the results were compared with the results of an age- and sex-matched group (comp group) (n = 140). RESULTS: Heterotropia 68.9% (comp group 3.6%; p < 0.001), abnormal head posture 41.3% (comp group 0; p < 0.001), nystagmus 44.0% (comp group 0; p < 0.001), stereo acuity < or =60'' 33.8% (comp group 97.1%; p < 0.001) and ocular motility defects 69.7% (comp group 0.7%; p < 0.001) were more common among children with hydrocephalus than in the comparison group. Children with overt hydrocephalus at birth had significantly more heterotropia (p = 0.0006), esotropia (p = 0.002), abnormal head posture (p = 0.02) and motility defects (p = 0.003) compared to those with hydrocephalus developing during the first year of life. The etiology, number of shunt revisions and the size of the ventricles had no significant effect on any of the investigated variables. CONCLUSIONS: Children with hydrocephalus surgically treated before the age of one year commonly present orthoptic abnormalities. The etiology of hydrocephalus, number of shunt revisions and ventricle size seem to be of minor importance compared with the age of onset of hydrocephalus with regard to the risk for orthoptic abnormalities.
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| 2. |
- Aring, Eva, 1959, et al.
(författare)
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Visual fixation development in children.
- 2007
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Ingår i: Graefe's archive for clinical and experimental ophthalmology = Albrecht von Graefes Archiv für klinische und experimentelle Ophthalmologie. - : Springer Science and Business Media LLC. - 0721-832X .- 1435-702X. ; 245:11, s. 1659-65
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The ability to keep steady fixation on a target is one of several aspects of good visual function. However, there are few reports on visual fixation during childhood in healthy children. METHODS: An infrared eye-tracking device (Orbit) was used to analyse binocular fixation behaviour in 135 non-clinical participants aged 4-15 years. The children wore goggles and their heads were restrained using a chin and forehead rest, while binocularly fixating a stationary target for 20 s. RESULTS: The density of fixations around the centre of gravity increased with increasing age (p < 0.01), and the time of fixation without intruding movements increased with increasing age (p = 0.02), while intruding saccades decreased with increasing age (p < 0.01). The number of blinks and drifts did not differ between 4 and 15 years, and there were no significant differences with regard to gender or laterality in any of the investigated variables. No nystagmus was observed. CONCLUSION: This study establishes values for visual fixation behaviour in a non-clinical population aged 4-15 years, which can be used for identifying children with fixation abnormalities.
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| 3. |
- Benfatto, Mattias Nilsson, et al.
(författare)
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Screening for Dyslexia Using Eye Tracking during Reading
- 2016
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 11:12
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Tidskriftsartikel (refereegranskat)abstract
- Dyslexia is a neurodevelopmental reading disability estimated to affect 5-10% of the population. While there is yet no full understanding of the cause of dyslexia, or agreement on its precise definition, it is certain that many individuals suffer persistent problems in learning to read for no apparent reason. Although it is generally agreed that early intervention is the best form of support for children with dyslexia, there is still a lack of efficient and objective means to help identify those at risk during the early years of school. Here we show that it is possible to identify 9-10 year old individuals at risk of persistent reading difficulties by using eye tracking during reading to probe the processes that underlie reading ability. In contrast to current screening methods, which rely on oral or written tests, eye tracking does not depend on the subject to produce some overt verbal response and thus provides a natural means to objectively assess the reading process as it unfolds in real-time. Our study is based on a sample of 97 high-risk subjects with early identified word decoding difficulties and a control group of 88 low-risk subjects. These subjects were selected from a larger population of 2165 school children attending second grade. Using predictive modeling and statistical resampling techniques, we develop classification models from eye tracking records less than one minute in duration and show that the models are able to differentiate high-risk subjects from low-risk subjects with high accuracy. Although dyslexia is fundamentally a language-based learning disability, our results suggest that eye movements in reading can be highly predictive of individual reading ability and that eye tracking can be an efficient means to identify children at risk of long-term reading difficulties.
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| 4. |
- Fahnehjelm, Kristina Teär, et al.
(författare)
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Visual function, ocular motility and ocular characteristics in patients with mitochondrial complex I deficiency
- 2012
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Ingår i: Acta ophthalmologica. - : Wiley. - 1755-3768 .- 1755-375X. ; 90:1, s. 32-43
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Tidskriftsartikel (refereegranskat)abstract
- Abstract. Purpose: The aims of the present study were to investigate visual function, ocular motility and ocular characteristics in children and young adults with complex I deficiency. Material and Methods: In a prospective study with longitudinal follow-up, the visual and ocular outcome in 13 patients with deficiency in complex I [nicotine-amide adenine dinucleotide (NADH) dehydrogenase] in the mitochondrial respiratory chain is presented. The patients were diagnosed during 1995-2007 and assessed during 1997-2009 at a median age of 12.8 years (range 3.1-23.4). Results: Twelve of 13 patients had visual impairment and/or ocular pathology. Four of 10 patients who co-operated in visual assessment had a best corrected decimal visual acuity of A mutation in mitochondrial DNA. Only one patient had normal visual acuity and ocular outcome including refraction and visual fields. Follow-up time was median 3.0 years (range 0-11). Conclusion: Visual impairment, ocular motility problems and OA are common in children and young adults with complex I deficiency and should prompt the paediatric ophthalmologist to consider mitochondrial disorders.
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| 5. |
- Hellgren, Kerstin, et al.
(författare)
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Visuospatial skills, ocular alignment, and magnetic resonance imaging findings in very low birth weight adolescents.
- 2009
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Ingår i: Journal of AAPOS : the official publication of the American Association for Pediatric Ophthalmology and Strabismus / American Association for Pediatric Ophthalmology and Strabismus. - : Elsevier BV. - 1528-3933 .- 1091-8531. ; 13:3, s. 273-9
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: To describe ocular alignment and stereoacuity in adolescents with very low birth weight (VLBW) in comparison with a matched control group and to investigate associations with white matter damage of immaturity (WMDI) and visuospatial skills in the VLBW group. METHODS: Fifty-nine 15-year-old VLBW subjects and 55 age- and sex-matched controls with normal birth weight underwent examination, including measurement of ocular alignment using cover test and Maddox rod and cycloplegic refraction. Stereoacuity was assessed with the TNO test, best-corrected visual acuity with a Konstantin Moutakis letter chart, and visuospatial skills with the performance tests, defined as performance intelligence quotient (IQ), in the Wechsler Intelligence Scale for Children (WISC-III). All VLBW subjects underwent magnetic resonance imaging of the brain. RESULTS: Ocular misalignment was significantly more common in the VLBW group than in the control group (22% compared with 4%; p = 0.004). Exophoria, subnormal stereoacuity, and subnormal performance IQ were significantly more common in the VLBW group than in the control group (p = 0.006, p = 0.011, and p = 0.015, respectively). Ocular misalignment was associated with WMDI (p = 0.035) and subnormal performance IQ (p = 0.020). Of the VLBW subjects with ocular misalignment, 69% had WMDI and/or subnormal performance IQ. CONCLUSIONS: The VLBW adolescents had more visuospatial problems, lower stereoacuity, and more ocular misalignment than the control subjects. Ocular misalignment was associated with visuospatial deficiencies and/or WMDI in the VLBW group and was a better predictor for visuospatial deficits than WMDI.
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| 6. |
- Olsson, Monica, et al.
(författare)
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Ocular Motor Score (OMS): a clinical tool to evaluating ocular motor functions in children. Intrarater and inter-rater agreement
- 2015
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Ingår i: Acta Ophthalmologica. - : WILEY-BLACKWELL. - 1755-375X .- 1755-3768. ; 93:5, s. 444-449
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Tidskriftsartikel (refereegranskat)abstract
- PurposeOcular motor score (OMS) is a new clinical test protocol for evaluating ocular motor functions in children and young adults. OMS is a set of 15 important and relevant non-invasive ocular motor function parameters derived from clinical practice. The aim of the study was to evaluate OMS according to intrarater and inter-rater agreement. MethodsForty children aged 4-10years, 23 girls median age 6.5 (range 4.3-9.3) and 17 boys median age 5.8 (range 4.1-9.8) were included. The ocular motor functions were assessed and scored according to the OMS protocol. The examinations were videotaped. To obtain the intrarater agreement, the first author examined and scored the children twice, first in the clinic and 2weeks later by watching the videotape. To obtain the inter-rater agreement, three other raters independently scored the ocular motor function of the children by watching the videotapes. ResultsThe overall observed intrarater agreement was 88%, and the observed inter-rater agreement between the three raters was 80%. For none of the subtests was there an observed intrarater agreement lower than 65%. Three of the subtests had an observed inter-rater agreement of 65% or below. ConclusionOverall there was high observed intra- and inter-rater agreement for the OMS test protocol. Subtests such as saccades and smooth pursuit were more difficult for raters to score similarly according the clinical OMS test protocol.
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| 7. |
- Pansell, Tony, et al.
(författare)
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Drift in ocular counterrolling during static head tilt
- 2005
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Ingår i: Annals of the New York Academy of Sciences. - : Wiley. - 0077-8923 .- 1749-6632. ; 1039, s. 554-557
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Tidskriftsartikel (refereegranskat)abstract
- A decreasing drift of the counter-rolled eye position (OCR) during head tilt was recently described. The underlying mechanism is not known. OCR in eleven healthy subjects was recorded (Search coil, Skalar) during a head tilt paradigm in two test conditions. The head was tilted with a velocity below (test 1) and above (test 2) detection threshold for the semicircular canals (SC) and held static for eight minutes. A significant drift of OCR was revealed in test 2 (P = .0006, ANOVA) and close to significant in test 1 (P = .07). No statistical difference was found between the two test conditions. The results suggest that the OCR drift was not caused by the SC complex merely.
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| 8. |
- Pansell, Tony, et al.
(författare)
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Drift in ocular torsion during sustained head tilt
- 2005
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Ingår i: Strabismus. - : Informa UK Limited. - 0927-3972 .- 1744-5132. ; 13:3, s. 115-121
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: A head tilt towards the shoulder (roll) induces an ocular counter-roll (OCR), i.e. torsion in the opposite direction to the head. How this counter-rolled position is maintained during a static head tilt is in debate. In a previous study, we reported an OCR-increasing drift subsequent to the head tilt. This finding is in contrast to other reports where no such response was found. The primary aim of this study was to repeat the experiment during a prolonged head-tilt test and to describe the OCR characteristics. A secondary aim was to investigate the influence of spatial visual cues on OCR. METHODS: Five male subjects performed a head tilt (30 degrees ) towards the right shoulder while the eye position was recorded during a 10-minute interval. In test 1, the subjects viewed a target with no cues for spatial orientation. The same head-tilt paradigm was repeated in test 2 with a visual target with spatial cues. Two samples of data were extracted from the start and the end of the recordings for statistical analysis. RESULTS: Subsequent to the head tilt, a slow OCR-increasing drift in the opposite direction to the head roll was found in all subjects. On average, this drift lasted for 30 sec (+/- 5) in test 1 and for 55 sec (+/- 18) in test 2. The drift was then found to change its direction, i.e. the eyes were rotated in the same direction as the head roll. When measured after 10 minutes, the OCR was significantly decreased. CONCLUSIONS: The OCR during static head tilt is not constant. During the first minute there is a gradually increasing OCR. Thereafter, the amplitude of the OCR decreases gradually. These changes are influenced to some extent by spatial visual cues. Possible mechanisms are adaptive responses in otolithic afferents as well as central nervous memory functions related to the semicircular canal system.
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