ABSTRACT
Background: In the field of multisensory integration, vision is generally thought to dominate audiovisual interactions, at least in spatial tasks, but the role of binocular fusion in audiovisual integration has not yet been studied. Methods: Using the Maddox test, a classical ophthalmological test used to subjectively detect a latent unilateral eye deviation, we checked whether an alteration in binocular vision in young patients would be able to change audiovisual integration. The study was performed on a group of ten children (five males and five females aged 11.3±1.6 years) with normal binocular vision, and revealed a visual phenomenon consisting of stochastic disappearanceof part of a visual scene caused by auditory stimulation. Results: Indeed, during the Maddox test, brief sounds induced transient visual scotomas (VSs) in the visual field of the eye in front of where the Maddox rod was placed. We found a significant correlation between the modification of binocular vision and VS occurrence. No significant difference was detected in the percentage or location of VS occurrence between the right and left eye using the Maddox rod test orbetween sound frequencies. Conclusion: The results indicate a specific role of the oculomotor system in audiovisual integration in children. This convenient protocol may also have significant interest for clinical investigations of developmental pathologies where relationships between vision and hearing are specifically affected.
ABSTRACT
A literature review of the important findings discovered over the past three decades on ocular movements during reading is presented herein. This fairly recent function in human evolution is a sophisticated sensorimotor and cognitive activity that brings very complex neurological and motor mechanisms into play. However, knowledge in this field is limited, even though reading problems are very common in children. We collected all the references in PubMed dating from 1969 to 2009 using the following "binocular coordination", "eye movements", "reading", and "dyslexia". When reading, the visual axes move in a very particular way, notably with regard to the parallelism of the ocular axes when saccades are triggered to reach the words to be read and during fixations, which enable decoding. In fact, when reading, the visual axes are often disassociated, even going as far as to intersect in a considerable number of cases. There are relatively few studies that have examined binocular coordination during reading. We are beginning to understand how the ocular axes move during horizontal saccades. Three-dimensional studies could be the next step to providing more precise data.
Subject(s)
Eye Movements/physiology , Reading , Child , Child Development/physiology , Dyslexia/etiology , Dyslexia/physiopathology , Humans , Saccades/physiology , Vision, Binocular/physiologyABSTRACT
PURPOSE: To evaluate the consequences of proprioception changes induced by a postural treatment on cognitive disturbances in children suffering from developmental dyslexia. MATERIAL: and methods: Twenty male dyslexic children were treated with prisms within their spectacles and a postural treatment. A control group of dyslexics (n=13) only received spectacles without prisms. All participants were evaluated at the beginning of the study and 6 months later with reading impairment tests and postural examinations. RESULTS: Mean age was 11 years and 5 months in the treated group and 11 years and 7 months in the control group. Four children were excluded from the 6-month analysis because of poor compliance. All dyslexic children presented with a postural deficiency syndrome. In 13 out of 16 treated children, dyslexia was improved at 6 months, especially for the global leximetric test and the reading of regular and irregular words. However, the treatment did not allow a complete recovery of reading ability when compared with age-matched individuals. CONCLUSION: Our results show that postural modifications may favorably influence some clinical signs associated with developmental dyslexia. Further studies with a larger sample and with a longer follow-up period are required to better assess the role of postural treatment in developmental dyslexia.
Subject(s)
Dyslexia/rehabilitation , Eyeglasses , Postural Balance , Proprioception , Somatosensory Disorders/rehabilitation , Adolescent , Case-Control Studies , Child , Dyslexia/complications , Dyslexia/diagnosis , Humans , Male , Posture , Prospective Studies , Refractive Errors/diagnosis , Refractive Errors/rehabilitation , Somatosensory Disorders/diagnosisABSTRACT
INTRODUCTION: The aim of this study was to assess the suitability of screening diabetic retinopathy (DR) with an itinerant nonmydriatic camera. METHODS: This program required collaboration between ophthalmologists and general practitioners. Three professional organizations gave their support: L'union Professionnelle des Médecins Libéraux de Bourgogne (UPMLB), le Fonds d'Aide à la Qualité des Soins de Ville (FAQSV), et la Fédération des Associations des Diabétiques de Bourgogne (FADB). The screening programm took place from November 2004 to June 2005 throughout the Burgundy region. General practitioners, health professionals (pharmacists, nurses), local media, and health insurance offices informed patients of the DR screening. An orthoptist took photographs with a nonmydriatic digital camera. Each patient had four fundus photographs without pupillary dilatation. Photographs were analyzed in the Department of Ophthalmology of Dijon's General Hospital. RESULTS: In this study, 676 diabetic patients were screened. Among these patients, 58 had DR, exclusively nonproliferative retinopathies. Nine percent of the photographs were ungradable. The mean age of patients with DR was 65 years. The mean onset of diabetes was 18 years before the study. Insulin therapy was followed by 27 patients (46.6%). Hemoglobin A1c was known in 26 patients (44.8%), with a mean value of 8.14%. Nearly 60% of patients with DR did not have their recommended annual consultation. After screening, 84% of patients consulted an ophthalmologist. CONCLUSION: Screening DR with an itinerant nonmydriatic camera can improve ophthalmologic follow-up of diabetics in rural areas. This screening program has continued in 2006 with an adapted vehicle.
Subject(s)
Diabetic Retinopathy/epidemiology , Adolescent , Adult , Age of Onset , Fluorescein Angiography , France/epidemiology , Humans , Mass Screening , Ophthalmology , Physicians, FamilyABSTRACT
PURPOSE: The objective of this study is to assess proprioception anomalies in postural deficiency syndrome in a group of children suffering from reading impairment. MATERIAL AND METHODS: Sixty male patients with an average age of 11 years and 9 months were included in the study. Initially, they were given a standardized neuropsychological examination, which confirmed the diagnosis of reading impairment. Then after filling out a questionnaire seeking a proprioceptive anomaly, the patients were subjected to a clinical ocular and postural examination consisting of nine precisely described steps. RESULTS: All of the patients recruited for the study presented clinical signs confirming a proprioception disorder found as a part of postural deficiency syndrome. CONCLUSION: This study opens a new direction for research concerning the origin and treatment of at least some reading-impaired children.
Subject(s)
Dyslexia/physiopathology , Eye/physiopathology , Postural Balance , Proprioception , Sensation Disorders/epidemiology , Adolescent , Child , Dyslexia/complications , Humans , Incidence , Male , Sensation Disorders/complications , Sensation Disorders/physiopathologyABSTRACT
The "skew deviation" also called Hertwig Magendie syndrome is an ocular static disease. Two features are encountered: conjugate deviation and vertical divergence with one eye with upward gaze and the other with one downward gaze. The authors report a simple case in a 50 years old woman. The role of M.R.I. or C.T. scan in the diagnosis is emphasized. The pathogenic mechanism remains obscure.
