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An Approach to Oculomotor Anomalies in a Child
Published in Vivek Lal, A Clinical Approach to Neuro-Ophthalmic Disorders, 2023
Intermittent exotropia is characterized by occasional outward drifting of the eyes combined with periods of binocular fusion. Intermittent exotropia may present as an intermittent unilateral eye deviation or alternating strabismus. Since intermittent exotropia is the most common form of divergent strabismus,5 a high index of suspicion should be held for it in all cases of exotropia. The underlying cause of intermittent exotropia is not well-defined, but the characteristics are so typical that further workup is rarely indicated. Patients typically present with exotropia occurring within the first decade of life, monocular squinting in sunlight or photophobia, and normal stereopsis when in periods of fusion. In children with exotropic deviations, it is important to assess for the control of their deviation which is typically better in cases of intermittent exotropia than in other more ominous neurologic etiologies of exotropia.
Head and Neck Muscles
Published in Eve K. Boyle, Vondel S. E. Mahon, Rui Diogo, Handbook of Muscle Variations and Anomalies in Humans, 2022
Eve K. Boyle, Vondel S. E. Mahon, Rui Diogo, Warrenkevin Henderson, Hannah Jacobson, Noelle Purcell, Kylar Wiltz
The absence of inferior oblique may cause ptosis (Posey 1923). DeAngelis and Kraft (2001) found that eyes with double-bellied inferior oblique muscles had a higher incidence of fundus excyclotropia. A band from the apex of the orbit to the inferior oblique and lower eyelid may cause congenital paradoxical lower eyelid retraction (Richardson et al. 2017). A variant insertion of inferior oblique may be associated with divergent strabismus (Prakash et al. 1983).
Eye
Published in A. Sahib El-Radhi, Paediatric Symptom and Sign Sorter, 2019
Strabismus – misalignment of the eyes – is a common ophthalmic problem, affecting 4%–5% of children younger than 6 years of age (Figure 9.2). It is associated with a significant negative impact on quality of life. Early detection and repair prevent visual and psychosocial dysfunction. Strabismus is diagnosed clinically, which involves examination of the corneal light reflex and cover test. It may be transient or constant, and manifest or latent. Because of different causes and treatments, it is important to divide strabismus into non-paralytic and paralytic. Non-paralytic strabismus includes inward deviation of the eyes (esophorias, commonly known as convergent or inward or crossed eyes), outward deviation of the eyes (known as exophorias, or divergent strabismus) and hyperdeviation (upward) and hypodeviation (downward) of an eye. Paralytic strabismus involves palsy of the third, fourth or sixth cranial nerve. Strabismus may be a congenital (or better termed infantile, as this allows inclusion of cases of strabismus that develop within the first few months of life) or an acquired form. One of the most important and serious causes of the acquired form of strabismus is retinoblastoma.
From monocular photograph to angle lambda: A new clinical approach for quantitative assessment
Published in Journal of Binocular Vision and Ocular Motility, 2022
Maxence Rateaux, Dominique Bremond-Gignac, Matthieu P. Robert
The evaluation of angle λ is important in refractive surgery for the optical zone centration and has also been used in cataract surgery for determining intraocular lens position.19–22 It is also crucial in the assessment of strabismus. A patient with a highly positive angle λ seems to exhibit a divergent strabismus, while he is orthophoric; a highly positive angle λ can minimize the visual aspect of an esotropia, and even offset it, according to the respective angle values.23 In contrast, a highly negative angle λ can simulate an esotropia. In all situations where the strabismus angles provided by cover-test measurements do not fit the observed or reported strabismus, and in all situations of fundus malformations, a precise quantification of angle λ can be useful. In this context, at least one smartphone application has been developed to measure ocular misalignment, which reportedly also provides an evaluation of “angle kappa.”24 However, so far, no simple method to quantify angle λ in daily strabismus practice is readily available. The use of corneal topography remains limited by its cost and restricted diffusion; besides, it is often time consuming and complex to manipulate, especially in young patients. Herein, we propose a new digital approach for the evaluation of horizontal angle λ, based on simple photographs of subjects’ eyes.
Thin-section 3D Steady-State MRI in Optic Nerve Coloboma
Published in Neuro-Ophthalmology, 2021
Krishnan Nagarajan, Anusha Venkataraman
A two-year-old boy presented with symptoms of divergent strabismus and visual impairment of his right eye. The child did not cooperate with vision testing. Right eye fundus examination revealed a ‘morning glory disc anomaly’ with a deepened optic disc suggestive of optic nerve coloboma. The macula was normal and there was no retinal detachment. Magnetic resonance imaging (MRI) was done to rule out other associated ocular and/or brain anomalies. The imaging was performed on a 1.5-T MRI scanner (HDX GE Healthcare, USA), using routine brain neuroimaging sequences. Fast Imaging Employing STeady-state Acquisition (FIESTA), a steady-state 3D sequence, was acquired at the level of orbits with the following parameters; TR, 4.8 ms; TE, 1.4 ms; slice thickness, 0.5 mm; FOV, 21 × 18.9 cm; matrix, 352 × 192; NEX, 4. A small defect of 1.5 mm diameter was noted in the optic nerve head with herniation of vitreous content into the defect confirming the coloboma (Figure 1a,b). The brain and left orbit were normal.
Preliminary Study: Impact of Strabismus and Surgery on Eye Movements When Children are Reading
Published in Strabismus, 2018
Faustine Perrin Fievez, Cynthia Lions, Maria Pia Bucci
All strabismic children underwent ophthalmologic and orthoptic examination including: visual acuity, measure of ocular deviation, stereoscopic acuity, and preferential eye [following5, suggestions]. The strabismus angle before and after surgery was measured by prism and cover test. As suggested by Espinasse-Berrod,17 to avoid after surgery decompensation, that is divergent deviation, convergent strabismus was measured by prism and unilateral cover test and divergent strabismus by prism and alternate cover test. Clinical data of each strabismic child are shown in Table 1. The monocular visual acuity was normal (≥20/20) for all children. A similar examination was also done 6 months after eye surgery (with a range of about ± 2 weeks). This time is needed for the complete stabilization of the new sensorial status of children after eye surgery.18