Orthoptics

‘’LE ROLE DE LORTHOPTISTE DANS LA PRISE EN CHARGE
PLURIDISCIPLINAIRE DES TROUBLES DE SPECTRE
AUTISTIQUE ‘’


Amine AISSAOUI 

Mémoire de Fin d’Etude en vue d’Obtention du Diplôme d’Orthoptiste 2020-2021
(Ecole IPIAB Casablanca)

Résumé :
L’autisme est un trouble envahissant du développement affectant les fonctions cognitives telles que la communication et les interactions de l’enfant avec le monde qui l’entoure, L'orthoptiste en tant que rééducateur de la fonction visuelle, outil essentiel de la communication, des apprentissages et de la vie sociale, est donc sollicité tant dans la phase de bilan autour du diagnostic. Les recherches publiées sur l’autisme sont diverses, Mais rares sont celles qui étudient l’intérêt de l’approche orthoptique au sein de la prise en charge multidisciplinaire. Dans un second temps nos statistiques montrent qu’une proportion assez importante d’enfants ; qui présentent des troubles visuels et des signes visuels suspect nécessitant un bilan et une prise en charge orthoptique, en revanche plus de 70 % des orthoptistes ne reçoivent pas de bilans puis n’ont pas une prise en charge de l’autisme à long terme.
Mots clés :  Bilan orthoptique REACS, Troubles visuels des TSA , Autisme , Prise en charge pluridisciplinaire , Orthoptie , Orthophonie.

To investigate the level of agreement between orthoptists and medical practitioners in the comprehensive eye examination of children seen in an orthoptist-led triage clinic. Patient records over a 6-month period were retrospectively reviewed. Those with a presenting complaint related to vision or ocular motility were triaged into the orthoptist-led clinic and included in the study. Patients who did not meet the triage protocol and those who were not assessed by a medical practitioner at a subsequent appointment were excluded from analysis. The clinical findings from the orthoptist and medical practitioner were collected and compared. In total, sixty-three patients were reviewed during the 6-month period and met the inclusion criteria. After the initial comprehensive eye examination with an orthoptist, thirty-two were discharged from hospital and thirty-one were asked to return for a review appointment with a medical practitioner. Agreement between the orthoptists and medical practit...

Orthoptic therapy was instituted in an adult, alternating esotrope with asthenopia who exhibited inaccurate static accommodative responses with adequate, clinically determined, accommodative facility. During and following therapy the patient showed considerable improvement in accommodative accuracy and related visual functions, such as contrast sensitivity, in the absence of any change in strabismic deviation. This case provides the first laboratory documentation of orthoptic effects on accommodation in an adult strabismic.

Engaging patients (parents/families) in treatment decisions is increasingly recognised as important and beneficial. Yet where the evidence base for treatment options is limited, as with intermittent distance exotropia (X(T)), this presents a challenge for families and clinicians. The purpose of this study was to explore how decisions are made in the management and treatment of X(T) and what can be done to support decision-making for clinicians, parents and children. This was a qualitative study using face to face interviews with consultant ophthalmologists and orthoptists, and parents of children with X(T). Interview data were analysed using the constant comparative method. The drivers for clinicians in treatment decision-making for X(T) were the proportion of time the strabismus is manifest and parents' views. For parents, decisions were influenced by: fear of bullying and, to a lesser degree, concerns around the impact of the strabismus on their child's vision. Uncertainty...

This case study demonstrates how the correction of ametropia influences the binocular vision and accommodation systems
of an individual. In this case, a patient reported to the Optometry clinic with complains of asthenopic symptoms and
intermittent diplopia. Careful history taking, ocular examinations and binocular vision assessment revealed accommodative
insufficiency and refractive error. The ocular examinations performed included; Visual Acuity, Slit lamp bimicroscopy and
funduscopy. The Binocular vision assessment included; Refraction, Extra Ocular Motility tests, Phoria measurement at far
and near, Near Point of convergence, Negative Fusional Vergence (NFV), Positive Fusional Vergence (PFV), Negative Relative
Accommodation (NRA), Positive Relative accommodation (PRA), amplitude of accommodation (AA), Binocular accommodative
facility (BAF), and Accommodative Convergence/ Accommodation Ratio (AC/A Ratio). Based on the findings of the above
tests, the appropriate treatment plan was given, and this consisted of vision therapy and spectacle dispensing.

Background: A Dyop (or dynamic optotype) is a spinning visual target which uses the strobic detection of the spinning gaps/segments of the ring to measure visual acuity. Methods: Forty subjects with visual acuity better than 6/12 (20/40) and ages between 20 and 28 years (24.48 ± 2.01 years) were recruited at the University of Benin Optometry Clinic. Snellen and Dyop acuity charts were displayed on a monitor at a distance of 6 meters. The assessment sequence between the two acuity chart formats was alternated for every other patient to reduce potential refractionist bias. Subjective refraction was measured in both eyes, and the duration of testing for each patient and each method was recorded. Results: There was no significant mean Thibos notations difference, M (p = 0.77), J0 (p = 0.27), and J45 (p = 0.57) using the Bland-Altman plot and 95% limits of agreement between the two charts, and there were no differences as to age or gender. There was, however, a disparity in the mean acuity of about 0.25 diopters with the mean Snellen acuity of 1.60 ± 0.21 decimal units and the mean Dyop acuity of 1.17 ± 0.14 decimal units with a linear relationship: y = 0.3121x + 0.6709 (p = 0.00). The refraction with a Dyop acuity chart also typically took half as long (339 ± 122 seconds) as the refraction with a Snellen acuity chart (680 ± 281 seconds), p = 0.00.

Fresnel prisms are often used in orthoptics for binocular anomalies and in low vision for visual field defects. These prisms are made of optical polyvinyl chloride (PVC) and this material increases chromatic dispersion and produces a loss of contrast. In this study, the effect of chromatic dispersion on contrast sensitivity is determined. Contrast thresholds over a wide range of spatial frequencies are obtained on a number of subjects with the use of Fresnel prisms ranging from 5 to 30 prism dioptres. As predicted there is a decrease in visual acuity and cut-off spatial frequency threshold as prism power increases. Similarly, a decrease in contrast sensitivity at high and medium spatial frequencies is recorded.

It is well known that vergence movements are important for distance appreciation, depth vision and stereopsis. Moreover, vergence movements are very probably used by the CNS during head and body motion to adjust the gain of the vestibulo-ocular reflex (VOR) according to the viewing distance. A recent clinical study of Anoh-Tanon et al. suggested that vertigo in children with normal vestibular function could be associated with abnormal vergence clinically assessed. The purpose of this study was to test this hypothesis with objective vergence eye movement recordings. We examined the latency of vergence, saccades and combined movements in twelve children with the complaint of vertigo but without vestibular abnormality. Convergence and saccades combined with convergence or with divergence had abnormally long latencies (relative to normal children of matched age). In contrast, divergence and isolated saccades showed only mild latency increase relative to normals. Lengthening of latency could be due to impaired cortical control. Orthoptic vergence training reduced all latencies; however, even the reduced latency of vergence and of combined movements was still abnormal. The improvement after orthoptic vergence training could be due to increased visual attention, although such mechanism cannot eliminate completely the initiation deficit of vergence movements. Objective eye movement recordings are thus useful for a diagnosis and treatment of children with vertigo.

Hypoxic brain damage is characterized by widespread, diffuse-disseminated brain lesions, which may cause severe disturbances in binocular vision, leading to diplopia and loss of stereopsis, for which no evaluated treatment is currently available. The study evaluated the effects of a novel binocular vision treatment designed to improve binocular fusion and stereopsis as well as to reduce diplopia in patients with cerebral hypoxia. Four patients with severely reduced convergent fusion, stereopsis, and reading duration due to hypoxic brain damage were treated in a single-subject baseline design, with three baseline assessments before treatment to control for spontaneous recovery (pretherapy), an assessment immediately after a treatment period of 6 weeks (posttherapy), and two follow-up tests 3 and 6 months after treatment to assess stability of improvements. Patients received a novel fusion and dichoptic training using 3 different devices designed to slowly increase fusional and disparity angle. After the treatment, all 4 patients improved significantly in binocular fusion, subjective reading duration until diplopia emerged, and 2 of 4 patients improved significantly in local stereopsis. No significant changes were observed during the pretherapy baseline period and the follow-up period, thus ruling out spontaneous recovery and demonstrating long-term stability of treatment effects. This proof-of-principle study indicates a substantial treatment-induced plasticity after hypoxia in the relearning of binocular vision and offers a viable treatment option. Moreover, it provides new hope and direction for the development of effective rehabilitation strategies to treat neurovisual deficits resulting from hypoxic brain damage.

In 2000, the UKs College of Optometrists commissioned a report to critically evaluate the theory and practice of behavioural optometry. The report which followed Jennings (2000; Behavioural optometry - a critical review. Optom. Pract. 1: 67) concluded that there was a lack of controlled clinical trials to support behavioural management strategies. The purpose of this report was to evaluate the