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Comparative Anatomy and Physiology of the Mammalian Eye
Published in David W. Hobson, Dermal and Ocular Toxicology, 2020
The extrinsic muscles are the rectus, oblique, and retractor muscles. There are four rectus muscles; dorsal, medial, ventral, and lateral. Contraction of each moves the eye in the direction of its name. The four recti originate adjacent to the optic foramen, from the Annulus of Zinn, and insert on the globe at variable distances from the limbus in the general region of the globe from which the name of the muscle is derived. There are two oblique muscles, the dorsal and ventral. The dorsal oblique muscle also originates from the annulus and courses forward through a condensation of fibroelastic connective tissue, the trochlea, in the medial aspect of the orbit. The dorsal oblique then extends laterally to insert both below and above the insertion of the lateral rectus. Although complex, the primary action of the superior oblique is intorsion. The ventral oblique originates from the medial orbital wall and inserts close to the insertion of the lateral rectus from a ventral position. As in the case of the superior oblique, its action is complex but its primary action is extorsion.
Early onset strabismus, DVD and A pattern : efficacy of the superior rectus recession
Published in Jan-Tjeerd de Faber, 28th European Strabismological Association Meeting, 2020
We have retrospectively studied eight consecutive patients aged from 3 to 31 years (mean : 14,6 years), presenting an A pattern with a size of incomitance from 10 to 45 PD (mean:20 PD) They had not undergone prior surgery on the oblique muscles.
Visual Assessment of Postural Antecedents to Nonspecific Low Back Pain
Published in David Lesondak, Angeli Maun Akey, Fascia, Function, and Medical Applications, 2020
As Figure 12.4 shows, there is a dissectible, continuous myofascial layer that “touches in” and blends in its deeper aspect to the periosteal/ligamentous layer, but with the more superficial layers communicating beyond these attachments. If sustained muscle contraction can have effects beyond the confines of their listed attachments, this pull must be sustained by strong collagen fibers aligned with the line of pull. Fascia has a grain, like wood, and repetitious patterns of myofascial force transmission occur mainly along these pathways. Sudden forces that occur oblique to these pathways can cause injury.
Normative orbital measurements in an Australian cohort on computed tomography
Published in Orbit, 2023
Khizar Rana, Valerie Juniat, Wen Yong, Sandy Patel, Dinesh Selva
The superior oblique muscle was measured on a coronal plane perpendicular to the muscle belly. The inferior oblique was measured on a coronal plane and a quasi-sagittal plane parallel to the orbital axis, below the centre of the inferior rectus tendon. Similarly, by using high-resolution CT orbit studies, we were able to reconstruct the quasi-sagittal plane and measure the inferior oblique muscle under the centre of the inferior rectus tendon. Previous MRI studies measuring the inferior oblique muscle have used quasi-sagittal sequences with a higher 2–3 mm slice thickness.16,17 A 2–3 mm slice thickness would make standardisation of the slice under the inferior rectus tendon less reliable. Additionally, dedicated quasi-sagittal MRI sequences are not widely available and are limited to specific indications.18
Augmented Lateral Rectus Recession for Consecutive Exotropia
Published in Journal of Binocular Vision and Ocular Motility, 2021
David Nash, Michael C. Brodsky
All patients had a constant exotropia at distance and near fixation, except for one who had intermittent exotropia both distance and at near, and another who manifested an intermittent exotropia only at near (Table 1). Two patients had near exodeviations that exceeded the distance exodeviation by small amounts (four PD in case 2 and six PD in case 8) with no associated adduction limitation or horizontal incomitance. One patient (case 6) had bilateral superior oblique overaction, and another (case 5) had previously undergone inferior oblique weakening in association with bimedial recessions. Five patients (cases 1,2,7,8,9) had a history of patching for amblyopia. Three patients (cases 1,4, and 6) had trace adduction deficits but all had distance exodeviations that equaled or exceeded their near deviations. Preoperative Titmus testing showed detection of the stereo fly in two patients and no detectable stereoacuity in the remaining patients. Three patients (cases 1, 4, and 8) had a history of mild prematurity, without neurodevelopmental abnormalities, and one (case 2) had a history of mild developmental delay.
Acute Onset Variable and Progressive Trochlear Nerve Palsy and Ophthalmoparesis Secondary to Bilateral Carotid Cavernous Fistula
Published in Journal of Binocular Vision and Ocular Motility, 2021
Lucas Bonafede, Anant Patel, Mays El-Dairi, Daniel J. Ozzello, Federico G. Velez
Ophthalmoparesis most often involves the oculomotor (III) and the abducens (VI) nerve, either isolated or together.3,4 However, there are few reported cases of isolated trochlear (IV) nerve palsies from CCF.3,5,6 Our case presented initially as a right superior oblique paresis associated with headaches. Interestingly, the superior oblique atrophy noted on MRI is an indication of chronicity. This finding may signify that there was a longstanding previously compensated SOP possibly related to a chronic posterior CCF. In this case, comitance developed shortly after, which may have been an indication of a developing third cranial nerve palsy, which may be supported by the development of a right supraduction deficit at the last visit. Interestingly, the presentation evolved with the patient developing a left restrictive strabismus with associated orbital congestion. Furthermore, there was a limitation to abduction in both eyes suggesting developing sixth nerve palsies. These findings prompted further evaluation with neuroimaging which revealed a right-sided posteriorly draining CCF ipsilateral to the SOP and a left-sided anteriorly draining CCF ipsilateral to the orbital congestion. Furthermore, embolization of the CCF led to rapid resolution of the patient’s diplopia, orbital congestion, and headaches.