Coup de sabre presenting with worsening diplopia and enophthalmos

A middle-aged woman with a diagnosis of linear scleroderma and systemic sclerosis presented with an atrophic skin lesion of the forehead extending in the right orbit and progressive diplopia in the right gaze. On exam, she had enophthalmos with a small, manifest esotropia in the right gaze. Orbital MRI revealed fat atrophy of the right upper eyelid and orbit not previously described. Inflammation and progressive collagen fibrosis involving subcutaneous tissue, fat, and muscle secondary to linear scleroderma may result in enophthalmos and diplopia.     

Extraocular muscle enlargement

Graefe's Archive for Clinical and Experimental Ophthalmology - Extraocular muscle enlargement can occur secondary to a range of orbital and systemic diseases. Although the most common cause of...     

Extraocular muscle involvement in MALT lymphomas

We report 3 cases of extraocular muscle involvement by MALT (mucosa-associated lymphoid tissue) lymphoma. The first case was a 68-year-old woman who presented with mild proptosis of the left eye and diplopia caused by a lymphoma in the medial rectus. The other two cases presented with ptosis caused by a lymphoma in the most anterior aspect of the levator muscle. MALT lymphoma may involve extraocular muscles, either as a primary or secondary presentation. Although localization of orbital lymphoma in extraocular muscles is rare, this possibility should be considered in the differential diagnosis with other conditions involving extraocular musculature.     

Extraocular muscle regeneration in freeze-treated extraocular muscle autografts

New growth of extraocular muscle has been demonstrated in degenerating peripheral nerve autografts implanted between two extraocular muscles. This suggests that extraocular muscle may be lengthened for therapeutic purposes if a suitable matrix can be found to support this new growth. Investigators of peripheral nerve regeneration have found that the basal lamina of freeze-killed skeletal muscle remains intact and supports axonal regeneration. This study was designed to investigate the feasibility of inducing regenerative growth of extraocular muscle in freeze-treated extraocular muscle autografts. In six beagles the inferior oblique muscle was removed from both orbits, frozen in liquid nitrogen, and allowed to thaw at room temperature. The freeze-thaw cycle was repeated. The freeze-treated grafts were then sewn in an end-to-end fashion between the cut end of the lateral rectus and the globe. At both 4 and 8 weeks postoperatively, three dogs were killed, and the grafts were removed from both orbits. These were prepared for light and electron microscopic examination. This revealed robust growth of mature-appearing, innervated muscle fibers in the proximal graft that could be differentiated by adenosine triphosphatase histochemistry. Rare, immature fibers were seen in the distal graft. These results demonstrate that freeze-treated extraocular muscle autografts support regenerative growth of extraocular muscle.     

Extraocular muscle involvement in Wegener's granulomatosis

A 44-year-old man with Wegener's granulomatosis involving the upper and lower respiratory tracts developed a diplopia with involvement of three extraocular muscles of one eye and one extraocular muscle of the other eye. The ocular and orbital examinations were otherwise normal, as were computerized tomography (CT) scans of the brain and orbits. The patient was treated with systemic Cytoxan and Prednisone and the respiratory and extraocular muscle abnormalities cleared within 1 month. Because of the bilateral extraocular muscle involvement, the absence of central nervous system or orbital findings, and the rapid and complete resolution after Cytoxan and Prednisone therapy, a diffuse vasculitis affecting the extraocular muscles was implicated as the etiology of the diplopia.     

Extraocular muscle proprioceptors and proprioception

Uncertainty of the roles of proprioception and efference copy in visual spatial perception persists. Proprioception has won back some support recently mainly on the evidence gained from physiological experiments in man, and rather than being mutually exclusive, the two mechanisms have been presented as collaborating. Another view supported by human and animal experiments states that current visual spatial perception may be served by efference copy whereas proprioception is responsible for temporal adaptations of the system. Certain characteristics of visuomotor cells of the monkey cortex can be explained assuming an efference copy input. Anatomical data from different sources are not easily reconciled. Disagreement about the nerve pathway of muscle afferents weakens arguments based on the results of open loop experiments involving nerve lesions in monkeys. The assumed presence of Golgi tendon organs in human extraocular muscles is no longer tenable and instead, palisade endings similar to those of cats and monkeys and other, irregular nerve endings are described. But man differs in having a limited and patchy distribution of neurotendonous endings and moreover, they may develop only after infancy. The allocation of a sensory function to palisade endings in myotendinous cylinders appears secure, at least in cats. Detailed examination of muscle spindles in man reveals anomalies of structure sufficient to question their capacity to provide useful proprioceptive information. One of the anomalies is the atrophy of intrafusal muscle fibres, present in both infant and adult muscles, and it is proposed that the redundant sensory endings, which do not appear to degenerate, search for new targets and may account for the random presence of tendon nerve endings. These observations place the role of proprioception in human extraocular muscles in jeopardy; they are unsupportive of the recent physiological studies and favour efference copy.     

Extraocular muscle surgery in myasthenia gravis.

Myasthenia gravis is typically a disease of young people in active employment who need a field of binocular single vision. Although it is systemically controllable with a good chance of spontaneous remission, persistent loss of binocularity may cause chronic disability. We report our experience of extraocular muscle surgery in five patients with stable myasthenia gravis and persistent double vision. Extraocular muscle involvement was selective, giving rise to incomitant and concomitant squints, with individual muscle overactions as well as underactions. Treatment was by conventional recession and resection procedures with the additional use of Faden and adjustable sutures where appropriate. In all five cases a larger, stable field of binocular single vision was established. It is concluded that extraocular muscle surgery may be beneficial in selected cases of myasthenia gravis.     

Extraocular muscle forces in alert monkey.

We describe an extraocular muscle (EOM) force transducer that provides low-noise signals from an alert animal for several months, is implanted without disinserting the muscle, and is well-tolerated by the body, and present results obtained with the device. The transducer can be used to study orbital statics and dynamics, and oculomotor control signals undiminished by orbital low-pass filtering and antagonistic pairing of muscles. It may provide an index of effective EOM innervation, useful in studies of orbital tissue healing and plasticity, and oculomotor (OM) signal adaptation. During horizontal saccades transducers implanted in the lateral rectus (LR) and medial rectus (MR) of a monkey trained to fixate revealed an agonist muscle tension waveform corresponding to the "pulse-slide-step" pattern of saccadic innervation, and an antagonist waveform that was similar within a scale factor. We never observed transient increases in antagonist force at the ends of saccades (active braking) or at the beginnings. Onset of saccadic force in LR preceded that in MR by 1.6 msec for abducting saccades, and lagged that in MR by 1.1 msec for adducting saccades. During vertical saccades, transient force changes were found in LR and MR, which were likely due, at least in part, to globe translation. LR and MR forces during fixation tended to be largest with the eye about 10 degrees in elevation, and smallest in depression, indicating that effective total innervation was a function of vertical gaze, or that there was variation in the elastic component of muscle force related to orbital geometry, with LR and MR innervation independent of vertical gaze. An exponential decrease in fixation force, having a time constant of about 10 days, was observed after implantation. This may have reflected adaptive muscle lengthening or post-surgical healing.     

Extraocular muscle imaging in complex strabismus.

BACKGROUND AND OBJECTIVE: Abnormalities of extraocular muscle are an unusual cause of complex strabismus. The traditional evaluation based on clinical examinations is insufficient for the interpretation of incomitant motility disorders resulting from extraocular muscle anomalies. Extraocular muscle imaging by computed x-ray tomography (CT) or magnetic resonance imaging (MRI) can provide useful information for diagnosis, pathophysiology, and treatment of complex strabismus. PATIENTS AND METHODS: Five cases of complex strabismus resulting from congenital anomalies of the extraocular muscles and their successful evaluation using extraocular muscle imaging are described. RESULTS: Orbital CT or MRI scan was obtained in five patients who had unusual incomitant strabismus. It confirmed the diagnosis of the absence of the medial rectus muscle, accessory lateral rectus muscle, atrophy of the inferior or both superior and medial rectus muscles, and abnormal thickening of the levator palpebrae superioris and superior rectus muscle. CONCLUSIONS: Extraocular muscle imaging is a useful technique for evaluating anatomic abnormalities. It should be considered when evaluating patients with atypical strabismus.     

Extraocular muscle imbalance after scleral buckling

Postoperative muscle imbalance was prospectively evaluated in 44 patients who underwent conventional scleral buckling operations. Strabismus was present in 27 of 44 patients (61%). Heterotropia resolved spontaneously during the first six postoperative months in nine of 27 patients (33%). Diplopia persisted in six patients (13.6%) and limitation of ductions occurred in 22 of 44 patients (50%). The risk of developing postoperative strabismus was 2.5 times longer if an implant was placed under a rectus muscle. Otherwise, presence, degree, and direction of the duction deficits did not correlate with placement of a local implant under the corresponding rectus muscles or their antagonists. Reoperation, preoperative detachment of macula and size of the local implant were not statistically correlated with extraocular muscle imbalance. We believe that decrease in postoperative swelling and increase in visual acuity that allows phoria adaptation are the main causes of spontaneous resolution.     

Extraocular muscle sideslip and orbital geometry in monkeys

The belly of each extraocular muscle is elastically coupled to both the globe and orbit. The dependence of muscle planes on gaze angle must be determined experimentally. In monkeys, radio-opaque markers were implanted along the upper and lower margins of a lateral rectus. A scleral search coil was implanted in the other eye. With the eye in various gaze positions, X-ray images were made to show the LR in the lateral view. We found that as the eye rotates vertically over 50 deg (+/- 25 deg), the point of tangency of the LR with the globe slips an average of 5.1 mm vertically with respect to the globe, allowing this point--and so the muscle plane--to remain approximately fixed relative to the orbit. The results of quantitative orbital dissections are presented in support of the sideslip calculations.     

Extraocular muscle imbalance after scleral buckling surgery

Pneumatic retinopexy is advocated to treat some retinal detachment cases, in part to avoid the complication of induced strabismus sometimes associated with scleral buckling procedures (SBPs). Prospective evaluation of postoperative muscle imbalance was performed in 76 eyes of 69 patients undergoing SBP. Measureable limitation of ductions occurred in 40 (73%) of the 55 eyes for which a full set of duction measurements could be obtained. Among 53 patients without previous retinal surgery in either eye, postoperative deviations were associated with encircling scleral buckles (P = 0.00003), but not with radial scleral buckles (P = 0.6). Significant strabismus occurred in 12 patients (23%), and three required surgery or prism therapy. Candidates for pneumatic retinopexy can usually be treated by a radial scleral buckling procedure, and therefore the risk of postoperative strabismus is low if this technique is selected.     

Extraocular muscle cysticercosis presenting as Brown syndrome

PURPOSE: Report of a case of acquired Brown syndrome caused by infestation of the superior oblique muscle by Cysticercus cellulosae. METHOD: Case seen in a referral practice. A 20-year-old man presented with recurrent attacks of conjunctivitis and diplopia in upgaze. Clinical examination of ocular motility established a diagnosis of acquired Brown syndrome of the right eye. Computed tomography of the right orbit unequivocally established the diagnosis of superior oblique muscle cysticercosis. The patient was started on systemic steroids and albendazole in the prescribed doses for a month. RESULT: Serial computed tomography scans of the orbit revealed resolution of the cystic lesion after a month. Clinically, although there was restoration of ocular motility in upgaze, mild restriction of movement of the right eye in levoelevation persisted. However, the patient was symptomatically better with amelioration of the recurrent conjunctivitis and diplopia in primary gaze. CONCLUSION: Extraocular muscle cysticercosis should be considered in the differential diagnosis of acquired motility disorder. The presentation of extraocular muscle cysticercosis as an acquired Brown syndrome is unusual. Response to medical therapy was satisfactory.     

手术治疗甲状腺相关眼病引起的限制性斜视

目的 探讨手术治疗甲状腺相关眼病（thyroid-associated ophthalmopathy,TAO)致限制性斜视的适应证,方法和效果。方法 采用牵拉作用最强眼外肌后徒术或断腱,矫治11例TAO致限制性斜视患者。手术前,后检查患者的眼位,眼球运动和双眼视功能等情况。结果 11例患者中,9例术前有复视症状;10例行眼外肌后徒术,1例行眼外肌断腱术。术后治愈4例,明显改善4例,有所改善3例;2例患者恢复三级立体视功能。结论 手术治疗TAO致限制性斜视,可达到功能性治疗和美容的效果;复视是手术治疗的主要适应证;手术应以解除限制因素为主,采用纤维化眼外肌后徒术。     

静止期甲状腺相关眼病患者眼外肌病变的手术治疗

目的　探讨静止期甲状腺相关眼病(TAO)患者眼外肌病变的手术治疗时机、方法和效果。 方法　通过行被动牵拉试验,对 12例静止期TAO患者牵拉作用最明显的眼外肌施行后退术或悬吊术,手术前后检查眼位、眼球运动、双眼视等情况。 结果　11例患者症状均有明显改善,复视消失,眼球运动各方向到位, 4例立体视恢复或改善, 1例患者原在位复视消失,眼球运动有改善,但向某方向运动时仍有一定程度的限制。 结论　对静止期TAO患者眼外肌病变行手术治疗可有效消除复视、改善眼球运动。手术方法为解除限制性因素,退后或悬吊病变眼外肌。     

Extraocular muscle aspects of the treatment in dysthyroid ophthalmopathy

The Maximum width of four rectus muscles (MR, LR, IR, SR) was measured on CT films and followed for 1-2 years in 304 eyes of 160 patients with dysthyroid ophthalmopathy. Based on these parameters, steroid therapy with 100-150 mg betamethasone, intravenously and orally, 1.5 Gy Lineac radiation therapy was given to the retrobulbar tissue from two directions repeated for 10 days and combination therapy consisting of the above two therapies given at the same time were evaluated. Combination therapy yielded the best results. Steroid therapy showed little effect on MR, but remarkable effect on SR. It was speculated that different portions of the rectus muscles may be related to different responses of rectus muscles to different treatment regimen.