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Quantitative E.M.G. of E.O.M in patients with congenital fibrosis of the extraocular muscles (CFEOM1)
Published in Jan-Tjeerd de Faber, 28th European Strabismological Association Meeting, 2020
C. Schiavi, C. Bellusci, E.C. Campos
Electromyography with quantitative analysis was performed on EOM of the two adult patients and in the unaffected member. Superior rectus muscle as well medial and lateral rectus muscles were studied. Quantitative electromyography (QEMG) is a general term referring to the technique and conditions used to study the microphysiology of the motor unit (5). It permits the recording of a single muscle fiber action potential. Signal is recorded by using a single concentric needle electrode and the motor unit potential (MUP) is the compound action potential that reflects the electrical activity of the muscle fibers belonging to a single motor unit. During slight voluntary muscle contraction, this compound action potential is characterized by its consistent appearance with regard to shape and amplitude. The relevant parameters may be one or more of the following: amplitude, duration, area, phases and turns. Typically at least 20 MUPs are recorded from each muscle tested (5).
Eye Velocity Induced by Steps of Angular Velocity After Canal Plugging
Published in Michael Fetter, Thomas Haslwanter, Hubert Misslisch, Douglas Tweed, Three-Dimensional Kinematics of Eye, Head and Limb Movements, 2020
S. Yakushin, M. Dai, T. Raphan, J-I. Suzuki, B. Cohen
Bolts were implanted on the skull under anaesthesia to provide painless fixation of the head in stereotaxic coordinates during testing. Two scleral search-coils were implanted on the left eye. One coil was placed around the iris (Judge et al., 1980) to measure horizontal and vertical eye position. Another coil, threaded under the superior rectus muscle, lay on top of the eye to measure roll eye position (Dai et al., 1994).
Extraocular muscle surgery for torsion and strabismus associated with macular translocation surgery (MT360)
Published in A Peyman MD Gholam, A Meffert MD Stephen, D Conway MD FACS Mandi, Chiasson Trisha, Vitreoretinal Surgical Techniques, 2019
The lateral rectus muscle is then transposed superiorly, and attached adjacent to the temporal edge of the superior rectus muscle, approximately 7 mm from the limbus. In a similar fashion, the medial rectus muscle is transposed inferiorly and attached adjacent to the nasal border of the inferior rectus muscle. Silicone oil removal can then be performed by the vitreoretinal surgeon immediately following muscle surgery. Alternatively, the silicone oil can be delayed for 4–6 weeks after extraocular muscle surgery.
Comparison of Unilateral and Bilateral Surgical Approaches for the Treatment of Age-Related Divergence Insufficiency Esotropia
Published in Journal of Binocular Vision and Ocular Motility, 2022
Chavisa Bunyavee, Steven M. Archer, Chris Y. Wu, Monte A. Del Monte
Divergence insufficiency is a form of esodeviation that measures greater at distance, less or absent at near. Diplopia is often present only at distance fixation.1–3 Its clinical description first appeared in the medical literature more than a century ago and has been classified mostly depending on the presence of an associated neurologic pathology.4,5 Divergence insufficiency found in older adults without any neurologic sign is defined as age-related divergence insufficiency esotropia (ARDIE). It is also known as age-related distance esotropia,6 divergence insufficiency pattern esotropia,7 or divergence paralysis esotropia as a manifestation of sagging eye syndrome.8,9 Proposed etiologies include central or peripheral microvascular 6th nerve palsy, abnormal position of rest, decreased medial rectus muscle elasticity, increased convergence tonus with resulting shortening of the medial rectus muscles, and degeneration of the intermuscular connective tissue band between the lateral and superior rectus muscles resulting in the inferior displacement of the lateral rectus muscles (sagging eye syndrome).10–13 ARDIE has been increasingly diagnosed in the past decade, and symptoms can markedly affect patients’ quality of life.14
Nasal insertion of the superior oblique tendon presenting as Brown syndrome
Published in Strabismus, 2022
Ahmed Awadein, Ahmed Adel Youssef, Jylan Gouda
Nasal insertion of the superior oblique was reported before in cases with congenital fibrosis of extraocular muscles. Brodsky, while discussing the surgical management of the congenital fibrosis syndrome, reported a case where surgical exploration revealed anomalous superior oblique tendons.2 The right superior oblique tendon consisted of tight, bifid structure which was anteriorly displaced, and which resembled muscle rather than tendon. The left superior oblique tendon also resembled muscle and was attached posteriorly under the temporal border of the superior rectus muscle. In both eyes, the superior oblique tendons were recessed and transposed anteriorly to the temporal border of the superior rectus muscle, which markedly reduced the patient’s divergence in downgaze. Sener and colleagues described the surgical management of 52 cases of congenital fibrosis of the extraocular muscles; they mentioned 3 cases of heterotopic superior oblique muscles inserting 0–4 mm nasal and posterior to the superior rectus insertion.3 Hunter et al. also reported anomalous superior oblique tendon insertion in congenital fibrosis of extraocular muscles.4 They described seven cases with an anomalously inserted superior oblique tendon, identified immediately adjacent and nasal to the superior rectus muscle rather than in its usual location in the superotemporal fornix.
Safety and Long-term Scleral Biomechanical Stability of Rhesus Eyes after Scleral Cross-linking by Blue Light
Published in Current Eye Research, 2021
Yu Li, Fengju Zhang, Mingshen Sun, Lingbo Lai, Xiaotong Lv, Chong Liu, Mengmeng Wang, Ningli Wang
Seven 3 years old rhesus monkeys (14 eyes) without any ocular diseases and weighing 3.4–6.0 kg were included in the study. They were housed in clean, environmentally controlled rooms individually at Capital Medical University and provided free access to food and water throughout the study. All experimental procedures were approved by the Institutional Animal Care and Use Committee (AEEI-2014-127), and animal care adhered to the ARVO Statement for the Use of Animals in Ophthalmic and Vision Research. Sclera collagen cross-linking procedures were applied at the superior temporal quadrant of the right eye equator of all rhesus monkeys, while the left eye served as a control. A mixture of ketamine (10–25 mg/kg) and xylazine (0.8–1.5 mg/kg) was injected intramuscularly. Then, the conjunctiva was incised, and Tenon’s capsule was dissected to expose the sclera of the superior temporal quadrant of the eye. The temporal and superior rectus muscles were held with sutures (Dacron 5–0) to manipulate the eye position during the treatment. The cross-linking area, which diameter was 10 mm, was instilled with 0.5% riboflavin every minute for 20 min before irradiation and every minute during the 20 min irradiation period by syringe. A blue light (460 nm) illumination system (Obodi, Beijing Optoelectronic Technology Co., China) was used to deliver irradiation at 22.5 mW/cm2 to the cross-linking area. The control eye took the same procedure only without blue light illumination. An antibiotic salve was instilled into the conjunctival sac immediately after surgery as a prophylactic.