Superior oblique muscle amyloidosis mimicking myositis

A 47-year-old man presented with complaints of progressive diplopia in downgaze and a painful firm mass on the left medial superior canthus. On examination, there was marked hyperemia of the superior bulbar conjunctiva of the left eye. Systemic examination revealed erythematous papules on his trunk and pulmonary infiltrates. CT of the orbits revealed a fusiform enlargement of the left superior oblique muscle and diffuse infiltration of the left temporal region. Biopsy of the left superior oblique muscle and temporal muscle disclosed Congo red deposits that show apple-green birefringence under polarized light. A comprehensive systemic investigation failed to show any disease that could explain the amyloid deposits. The patient was then diagnosed as having primary systemic amyloidosis. We think that this case highlights the necessity of a biopsy in any atypical extraocular muscle enlargement before a diagnosis of myositis.     

Superior oblique muscle layers in monkeys and humans

PURPOSE: Rectus and the inferior oblique extraocular muscles (EOMs) consist of orbital layers (OLs), inserting on connective tissues, and global layers (GLs), inserting on the sclera. This study was performed to clarify the anatomic relationships of the corresponding layers of the superior oblique (SO) muscle. METHODS: Two whole human and two monkey orbits were serially sectioned en bloc at 10-mum thickness in the coronal plane and stained for collagen with Masson's trichrome and for elastin with van Gieson's stain. The SO muscles of one human and one monkey were sectioned longitudinally. The structure of the SO muscle was examined by light microscopy, and muscle fibers in the OL and GL of selected sections were counted. RESULTS: The deep SO muscle consisted of a central GL contiguous with the tendon, surrounded coaxially by a peripheral OL inserting on the SO sheath posterior to the trochlea. The maximum number of SO fibers was 14,400 to 19,200 in the human and 7,000 to 7,400 in the monkey. In the monkey, approximately 60% of total fibers were in the GL, and 40% in the OL. The SO sheath was in mechanical continuity with the superior rectus pulley. CONCLUSIONS: The primate SO has a substantial OL configured to contribute to positioning the superior rectus pulley in the coronal plane. Whereas the direction of application of the SO's GL force is determined by the rigid trochlea, the SO's OL influences the direction of application of rectus EOM forces. This insight extends the concept of active control of pulley positions to include a contribution from the SO muscle.     

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。     

Superior oblique muscle palsy in a patient with orbital dermoid cyst.

We describe the clinical and radiologic findings and surgical outcome of an orbital dermoid cyst causing a superior oblique muscle palsy in a child. Superior oblique muscle palsy in childhood is most often congenital. Less common causes are trauma, vascular lesions, neoplasms, and infections.(1,2) The most common orbital lesions in children are dermoid and epidermoid cysts.(3-5) A dermoid cyst at the region of trochlea is suspected as the cause of superior oblique muscle palsy in our case. This unusual presentation of a dermoid cyst has not been reported previously.     

Superior oblique muscle paresis and restriction secondary to orbital mucocele.

Mucoceles are chronic cystic lesions of the paranasal sinuses lined by respiratory epithelium. Their extension into the adjacent orbit may result in proptosis, ocular motility disorders, and diplopia. Brown syndrome secondary to extension of a mucocele into the orbit has been reported previously. Superior oblique (SO) muscle weakness, either isolated or in combination with an ipsilateral limitation to elevation in adduction, has not been previously reported in patients with orbital mucocele.     

Superior rectus muscle recession for residual head tilt after inferior oblique muscle weakening in superior oblique palsy

Purpose

Residual head tilt has been reported in patients with superior oblique muscle palsy (SOP) after surgery to weaken the inferior oblique (IO) muscle. The treatments for these patients have not received appropriate attention. In this study, we evaluated the superior rectus (SR) muscle recession as a surgical treatment.

Methods

The medical records of 12 patients with SOP were retrospectively reviewed. Each of these patients had unilateral SR muscle recession for residual head tilt after IO muscle weakening due to SOP. The residual torticollis was classified into three groups on the basis of severity: mild, moderate, or severe. Both IO muscle overaction and vertical deviation, features of SOP, were evaluated in all patients. The severity of the preoperative and postoperative torticollis and vertical deviation were compared using a paired t-test and Fisher''s exact test.

Results

The torticollis improved in nine of 12 (75%) patients after SR muscle recession. The difference between the preoperative and postoperative severity of torticollis was statistically significant (p = 0.0008). After surgery, the mean vertical deviation was significantly reduced from 12.4 prism diopters to 1.3 prism diopters (p = 0.0003).

Conclusions

Unilateral SR muscle recession is an effective method to correct residual head tilt after IO muscle weakening in patients with SOP. This surgical procedure is believed to decrease head tilt by reducing the vertical deviation and thereby the compensatory head tilt.     

Superior oblique muscle paresis aftersub-Tenon's anesthesia for cataract surgery

A 68-year-old man developed strabismus after having sub-Tenon's anesthesia forcataract extraction and intraocular lens implantation. An ipsilateral hypertropia with superior oblique muscle paresis developed in the operated eye. The hypertropia appeared 1 day after surgery and resolved 1 month later. Although sub-Tenon's anesthesia is considered safer than other methods of local anesthesia, strabismus may occur.     

Superior oblique tendon sheath syndrome.

Clinical examination of 15 patients with the superior oblique tendon sheath syndrome showed that 12 of them had some evidence of stenosing tenosynovitis.     

Thyroid ophthalmopathy presenting as superior oblique paresis.

Six patients with thyroid ophthalmopathy presented with what appeared to be a unilateral superior oblique paresis by the three-step test, which was eventually followed by more typical findings of thyroid disease. This early motility defect in thyroid ophthalmopathy may be caused by a restrictive process due to involvement of the inferior rectus muscle. Clues to the proper diagnosis included an increase in vertical deviation in upgaze, elevation of intraocular tension in upgaze, and the lack of excyclodeviation. These features should be assessed in patients with isolated superior oblique paresis.     

Superior oblique myokymia

Superior oblique myokymia (SOM) is a rare condition of unclear etiology. We discuss the history, etiology, clinical features, differential diagnoses, management, and prognosis of SOM. We conducted a meta-analysis of all 116 cases published since SOM was first described in 1906. The age at examination was 17–72 years (mean: 42 years.) There was a right-sided preponderance in 61% of cases (P < 0.02) that was statistically significant in females (63%, P < 0.04) but not in males (59%, P = 0.18). The pathophysiology of SOM may be neurovascular compression and/or ephaptic transmission. Although various pharmacological and surgical approaches to SOM treatment have been proposed, the rarity of the condition has made it impossible to conduct clinical trials evaluating the safety and efficacy of these approaches. Recently, topical beta blockers have managed SOM symptoms in a number of cases, including the first case treated with levobunolol. Systemic medications, strabismus surgery, and neurosurgery have been used to control symptoms, with strabismus surgery carrying a moderate risk of postoperative diplopia in downgaze. Although there is no established treatment for SOM, we encourage clinicians to attempt topical levobunolol therapy before considering systemic therapy or surgery.     

Superior oblique tendon lengthening for acquired superior oblique overactions.

Two patients who presented with compensatory head postures and diplopia are described. They both had marked unilateral superior oblique overaction, in one patient due to a large, incomitant skew deviation. Each underwent a superior oblique tendon lengthening procedure using a segment of silicone 240 retinal band as an expander, in combination with a contralateral superior rectus recession. Both achieved an excellent result with an improvement of the compensatory head posture and an increase in the field of binocular single vision. This surgical procedure is proposed as an option in the management of superior oblique overaction, including certain cases of skew deviation.     

Superior oblique tendon expansion in the management of superior oblique dysfunction.

Traditional superior oblique weakening procedures may be unpredictable and lead to superior oblique underaction. The use of 240 retinal band as a spacer to lengthen the superior oblique tendon has been proposed as a more controlled approach than superior oblique tenotomy and related procedures. The use of this technique is reported in a patient with diplopia following an orbital floor blow out fracture, and in a child with Brown's superior oblique tendon sheath syndrome.     

Superior oblique palsy manifested during pregnancy.

The author describes his experience with diplopia during uncomplicated pregnancy in 3 of 25 (12%) women with neurologically isolated unilateral superior oblique palsy. These three patients had visual sensory and ocular motor findings that suggested they had longstanding latent vertical deviations that decompensated during pregnancy. Two of these three women experienced resolution of symptoms shortly after delivery. Increased recognition of the benign association between decompensation of a latent superior oblique palsy and pregnancy may obviate the need to further evaluate such patients with neuroimaging studies or other procedures.     

甲状腺相关眼病眼肌损害的手术治疗

目的探讨甲状腺相关相病(TAO)伴有眼肌损害手术治疗的适应症，方法与效果。方法收集1995-2001年22例(24眼)TAO伴有眼肌损害患者，经保守治疗病情稳定后，主要行限制性纤维化眼肌后退术。结果术后随访6月-5年，平均2.5年，痊愈6例(27.3%),基本痊愈8例(36.4%),好转7例(31.8%),无效1例(4.5%)。结论手术治疗TAO合并眼肌损害是一种效果良好的治疗方法，手术适应症是有复视或代偿头位，手术方法主要是纤维化眼外肌后退术。