China
Africa
Explore chapters and articles related to this topic
Neuromuscular Junction Syndromes and Ocular Myopathies
Published in Vivek Lal, A Clinical Approach to Neuro-Ophthalmic Disorders, 2023
Ophthalmoparesis is the second most common manifestation of OMG9 but occurs quite rarely as an isolated feature (Figure 15B.3), being often associated with ptosis. The ocular motor dysfunction, which can affect any muscle or combination of extraocular muscles, is not specific and can present as any type of ophthalmoplegia, including neurogenic, i.e., resembling a sixth or a fourth nerve palsy. OMG can mimic in reality any ocular motor palsy pattern, including more complex features, such as internuclear ophthalmoplegia,10 nuclear gaze palsy, one-and-a-half syndrome,11 complete ophthalmoplegia, etc. Demonstration of fatigability (throughout the same examination or at two successive examinations), especially if associated with unilateral or bilateral ptosis, prompts suspicion of OMG. Fatigability can be demonstrated acutely, by asking the patient to sustain prolonged upward gaze, without blinking, which may worsen the ocular misalignment and/or ptosis. An appropriate history may reveal symptoms worsening as the day progresses and/or with fatigue and improving after physical rest. Spontaneous remission of the ocular signs, during months or years, is not uncommon. A few following associated signs are not consistent with OMG: pain, anisocoria, abnormal pupillary reactions to light, sensory or visual symptoms.
3rd Cranial Nerve Palsy
Published in K. Gupta, P. Carmichael, A. Zumla, 100 Short Cases for the MRCP, 2020
K. Gupta, P. Carmichael, A. Zumla
The 3rd cranial nerve (oculomotor nerve) supplies the medial rectus, superior rectus and the inferior oblique muscles. In addition it supplies the pupilloconstrictor and levator palpebrae muscles. It is important to understand the exact role of the extraocular muscles in the movements of the eyeball. For example, if a patient with right-sided 3rd nerve palsy is asked to look straight, the right eye will turn laterally because of the unopposed action of the lateral rectus (supplied by the 6th nerve) and diplopia results. When the patient is asked to look to the far right, both eyes can move in the right direction. If the patient is asked to look to the far left, the right eye (with the 3rd nerve palsy) fails to cross the midline because of the failed action of the medial rectus and diplopia results.
What can eye muscle studies tell us about strabismus?
Published in Jan-Tjeerd de Faber, 28th European Strabismological Association Meeting, 2020
Force measurements from horizontal eye muscles during normal eye movements have been performed in humans undergoing surgery for concomitant strabismus under topical anesthesia (Collins, O’Meara & Scott 1975, Lennerstrand et al. 2003). Extraocular muscles show a significant degree of activity even when the eye is directed well into the off-direction of muscle activity (Scott & Collins 1975). This would eliminate any slack in the muscle and permit it to operate within the linear region of muscle length-tension curves at all times. Recently it has been shown that force development in saccadic movements can be evaluated adequately with the muscles still attached to the globe (Lennerstrand et al 2003). This will allow extensive studies of contractile properties in different eye muscles during ophthalmic surgery under topical anethesia.
Congenital Fibrosis of Extraocular Muscles: A Systematic Review and Meta-Analysis
Published in Journal of Binocular Vision and Ocular Motility, 2023
Joshua M. Van Swol, Walter K. Myers, Shaun A. Nguyen, M. Edward Wilson
For patient and caregiver counseling and education, it would be helpful to know how many operations patients could expect to undergo for treatment of their disease. Additionally, it would be useful for providers to know the typical number of extra-ocular muscles operated on in individuals. According to our findings, the typical patient with CFEOM could expect to have one to two operations. Anecdotally, re-operations on the same muscle were rare in most studies. Thus, the second operation was usually either an eyelid ptosis repair or a surgery on the contralateral eye if the surgeon preferred to operate on one eye at a time. Further, Ophthalmologists can expect to operate on two to three extraocular muscles on each eye. As revisions are rare, this number can approximate the total amount of muscles operated on.
Giant cell arteritis
Published in Postgraduate Medicine, 2023
The most serious complication of GCA remains permanent visual loss which can occur in up to 20% of patients before glucocorticoid therapy initiation [66]. In a study of patients with biopsy-proven GCA, patients with ocular involvement were older, with a lower ESR and were less likely to have a headache or other systemic symptoms of giant cell arteritis than those without ocular involvement [67]. Two proposed reason for this variability in ocular involvement are the lack of classic symptoms of GCA making patients less likely to be referred for temporal artery biopsy and treatment in a prompt fashion and that those with a highly inflammatory response (elevated inflammatory indices) had more circulating IL-6 which has angiogenic properties and could counteract the arteritic ischemia of GCA [66]. GCA has a predilection for the ophthalmic artery and its branches most importantly the posterior ciliary arteries and the central retinal artery. The posterior ciliary arteries perfuse the choroid which nourishes the photoreceptors in the outer third of the retina and the optic nerve head. The central retinal artery provides blood to the inner two third of the retina including the retinal ganglion cells – the axons forming the optic nerve. The ophthalmic artery in addition to these two branches, also provides blood to the extraocular muscles and the vasa nervorum of the ocular motor nerves [68]. Vision changes in GCA have been described as a result of each of these vessels, in addition, vessels in the vertebrobasilar circulation can become involved which supplies circulation to the occipital lobe.
An upper cervical spine treatment protocol for cervicogenic dizziness: a randomized controlled trial
Published in Physiotherapy Theory and Practice, 2022
Andoni Carrasco-Uribarren, Jacobo Rodríguez-Sanz, Carlos López-de-Celis, Pablo Fanlo-Mazas, Sara Cabanillas-Barea
The cervico-ocular, vestibulo-ocular, and optokinetic reflexes work together to control the extraocular muscles. These systems help to create a clear view of images during head movement (Treleaven, Jull, and Grip, 2011). Different cervical problems can alter these reflexes and give symptoms such as dizziness and headache (Treleaven, 2008, 2011). In vestibular rehabilitation, practitioners try to improve patients’ vestibulo-ocular reflex. The goal of gaze stabilization exercises is to improve the patients’ gain of the impaired vestibulo-ocular reflex. To do this, head mobility exercises are performed with the gaze fixed on an object. This tends to improve stability and decrease the feeling of dizziness in patients (Whitney and Sparto, 2011). The present study shows improvements in the cervical range of motion during the fixed gaze test for the T1 (p < .050) and T2 (p < .001) follow-ups in the intervention group. It may be that the decrease in neck pain contributes to performing this test correctly with a higher range of motion.