Accessory Extraocular Muscle as a Cause of Restrictive Strabismus

Restrictive strabismus resulting from the presence of an accessory extraocular muscle has rarely been reported in the literature. Most articles written on this topic are isolated case reports. The purpose of this paper is to describe a series of 7 similar patients presenting with atypical restrictive strabismus associated with enophthalmos in the affected eye, which was found to be caused by an accessory extraocular muscle attached to the posterior globe near the optic nerve. The medical records of 7 patients who shared these clinical characteristics were retrospectively analyzed. Orbital imaging was obtained in the 7 cases, which were compared. Three of the patients were females and four were males. The left eye was affected in all 4 males and the right eye was affected in the 3 females. The 7 patients presented with the following clinical characteristics: enophthalmos, restriction to eye movements in most fields of gaze, and presence of an anomalous orbital structure that was interpreted on magnetic resonance imaging (MRI) to be an accessory extraocular muscle inserting onto the posterior surface of the globe in the affected eye. The fellow eye was normal in all cases. Five of the 7 patients underwent surgical correction with partial improvement in only one patient. The presence of an accessory extraocular muscle should be included in the differential diagnosis of patients with atypical restrictive strabismus. Orbital computed tomography or MRI are essential for correct diagnosis in these cases.     

Ultrasound Biomicroscopy in Strabismus Surgery: Efficacy in Postoperative Assessment of Horizontal Muscle Insertions

ABSTRACT

Purpose: To study the efficacy of ultrasound biomicroscopy (UBM) in assessment of extraocular muscle insertion sites after strabismus surgery.

Methods: This double masked prospective interventional study included 16 eyes of 15 patients with deviation <60 prism diopters (PD) who underwent primary horizontal strabismus surgery. Preoperative muscle insertion was measured by UBM and compared with measurements done intraoperatively by surgical caliper. Both measurements by surgical caliper were taken intraoperatively before and after performing the planned repositioning of the muscle insertion. Postoperatively muscle insertion was remeasured by UBM and compared with the presumed muscle insertion after surgery. Clinically limits of agreement of?±?1?mm were taken as acceptable.

Results: Mean age of patients was 21?±?3 years (range 16–28 years). Preoperative average distance of the medial rectus (MR) from limbus was 5.3?±?0.3?mm (4.9–5.9?mm) by the UBM and 5.6?±?0.3 (5–6?mm) by surgical caliper (p?=?0.05). For lateral rectus (LR), UBM measurements from the limbus were 6.8?±?0.7?mm (5.9–8.3?mm) and 7.1?±?0.4?mm (6.5–8?mm) by calipers (p?=?0.067). Post–op UBM at 3 months could visualize new muscle insertion for all operated MR muscles (i.e., 100% of cases) and for LR muscles in only 50% of cases. However, accuracy could be achieved only in 78.6% of cases for MR muscle and for LR in 62.5% of cases (among LR muscles that were visible post-op). Maximum distance posterior to the limbus that the UBM was able to detect MR was 11.2?mm and for LR was 13.5?mm.

Conclusion: UBM does not detect the new position of LR with any consistency postoperatively. Even after detection of muscle, the new insertion is only within ±1?mm of the actual muscle insertion in 62.5% of the cases. Hence it is not a reliable tool for planning resurgery.     

Incomitant strabismus: does extraocular muscle form denote function?

The paradigm that an "underacting" extraocular muscle is always atrophic or hypoplastic and that an overacting extraocular muscle should always be enlarged leads to inconsistencies with clinical observations. These include findings of "overacting" inferior oblique muscles, superior rectus muscle overaction or contracture syndrome, and normal extraocular muscle diameters in patients with apparent superior oblique muscle palsy, among other clinical entities. These inconsistencies can be reconciled if one accepts the possibility that extraocular muscle contractile activity may reflect a change in neural input to an anatomically normal muscle or that muscle contractile activity may be altered by shifts in fiber type and distribution within a normal-sized muscle. This remodeling may result from vergence adaptation or from any change in neural stimulus to the muscle. There is substantial evidence to suggest that both of these theoretical possibilities may likely occur.     

共同性斜视眼外肌的电镜观察

目的　通过对 76例共同性内、外斜视眼外肌及 7例正常眼外肌的电镜观察 ,探讨斜视发病机制。方法　应用电子技术对 3 4例共同性内斜视眼、 42例共同性外斜视眼及 7例非斜视行眼球摘除眼的眼外肌进行超微结构观察分析。结果　非斜视组肌细胞正常 ,肌丝 ,肌节排列整齐 ,方向一致 ,Z带清晰 ,线粒体分布正常 ,未见坏死 ,斜视患者弱侧眼外肌部分肌纤维不同程度萎缩 ,变性 ,肌原纤维稀疏 ,有的肌原纤维排列方向紊乱 ,线粒体增多 ,肌质网扩张 ;有 1例肌纤维坏死 ,结构消失 ,代之以纤维组织 ;有些有髓神经髓鞘结构破坏。结论　提示共同性斜视眼外肌的确产生超微结构改变。     

Traumatic Transection of the Lateral Rectus Muscle with Chorioretinitis Sclopetaria

Abstract

A man, aged 67 years, sustained monocular trauma to the left eye while gardening, presenting with light perception, complete absence of abduction, and chorioretinitis sclopetaria. At surgery, the lateral rectus was found to be transected at the equator of the globe, with an area of locally abraded sclera. A few posterior muscle fibers were identified and sutured to the residual anterior fibers. With a partial improvement of the esodeviation, after a further 6 months he proceeded to lateral transposition of the superior and inferior recti to healthy sclera 4?mm from the limbus, with adjunctive medial rectus botulinum toxin. Six months later, the angle of primary deviation remained stable at 4 prism diopters base out with improved abduction. Vision in the eye remained reduced at 20/200 (with eccentric fixation) due to macular changes secondary to the sclopetaria. In conclusion, this case describes a rare example of complete traumatic transection of the lateral rectus with chorioretinitis sclopetaria, due to orbital injury. With appropriate surgery, the angle of deviation can be considerably improved despite complete muscle transection and scleral injury.     

眼眶骨折伴斜视患者的临床诊治分析

目的 分析眼眶骨折伴斜视患者的斜视性质、眼眶骨折修复的手术时机和术后斜视的变化等.方法 回顾分析2001年1月到2008年12月在中山大学中山眼科中心诊治的眼眶骨折患者.常规作眼眶CT检查、被动转动试验、眼位和眼球运动检查、复像试验,观察眼眶骨折修复前后眼位和眼球运动情况等.结果 共87例90只眼,男性66例,女性21例;年龄3～68岁(平均30.6岁);右眶27例,左眶57例,双眶3例.36%的患者有视力受损.32%为眼眶爆裂性骨折,68%为复合性骨折;以内壁和下壁骨折多见.术前47%的患者有斜视,其中麻痹性41.5%,限制性58.5%;眼眶骨折修复后:35例术前有斜视者(平均随访1年),28.6%斜视消失;17.1%正前方和下方功能位置无斜视,37.1%斜视部分好转或不变;17.1%斜视加莺;1例术前无斜视,术后出现医源性斜视.结论 眼眶骨折伤后患眼斜视的性质包括麻痹性和限制性,骨折修复手术时机存在争论,以下情形需要尽快手术:(1)影像学检查显示有眼外肌断裂;(2)CT扣描和被动转动试验均示有明确的眼外肌嵌顿,保守治疗二周无好转;(3)外壁和上壁的Blow-in骨折.眼眶骨折修复术后其斜视既可消失也可不变或加重;医源性斜视要尽量避免.     

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.     

共同性外斜视眼外肌病理研究

目的：探讨共同性外斜视内直肌的病理变化与斜视发现时间的关系。
　　方法：对30例共同性外斜视患者行斜视矫正手术,术中将截除的内直肌用4%甲醛固定后送病理,在显微镜下观察眼外肌的组织结构,并进行HE和Masson染色。
　　结果：共同性外斜视30例中,内直肌纤维大小不一、形态异常,数量减少,肌肉不同程度的纤维化,经Masson染色后发现,发现斜视较久患者组眼外肌肌纤维含量明显少于发现时间较短患者组(P<0.05) 。
　　结论：斜视的发生与眼外肌的结构异常有关,发现斜视时间较久的共同性外斜视比发现时间较短的共同性外斜视其眼外肌发生明显的纤维化,说明内直肌纤维化可能是外斜视形成的原因之一。随着斜视时间的延长,眼外肌纤维化程度加重。     

Orbital wall approach with preoperative orbital imaging for identification and retrieval of lost or transected extraocular muscles.

PURPOSE: To report the results of an anterior approach along the orbital wall to recover a lost or transected extraocular muscle. METHODS: This is a retrospective review of lost or transected muscles retrieved by an anterior orbitotomy approach to the adjacent orbital wall because they were unable to be recovered by a standard conjunctival approach. Magnetic resonance imaging or computed tomography was performed on all subjects before surgery. RESULTS: Six patients underwent anterior orbitotomy via an orbital wall approach; all had undergone an attempted retrieval from a standard transconjunctival approach that failed. Five muscles had been lost from surgical or traumatic transection, and 1 muscle had been lost during strabismus surgery. The muscle location at retrieval ranged from 20 to 25 mm (mean, 23 mm) posterior to the limbus. The duration that these muscles were disinserted ranged from 7 days to 7.5 years (mean, 24 months). Preoperative deviation in primary gaze ranged from 15 to 50 PD, whereas first day postretrieval deviations all measured less than 8 PD. After a mean follow-up of 162 weeks, the mean deviation in primary gaze was 2 PD (range, orthotropia to 7 PD of esotropia). CONCLUSIONS: Anterior orbitotomy along the orbital wall with preoperative orbital imaging of extraocular muscle anatomy and function combine to create a valuable approach for retrieval of a lost or transected muscle. This technique may successfully retrieve lost or transected muscles that previously were irretrievable when using a standard transconjunctival approach.     

甲状腺相关眼病限制性斜视手术并发症的临床分析

目的:总结甲状腺相关眼病(thyroid associate dophthalmopathy,TAO)导致的限制性斜视手术并发症的常见原因及应对策略。方法:回顾性分析于2009-01/2012-02在我院就诊的21例眼外肌手术出现并发症的TAO限制性斜视病例,分析手术前病情、手术情况、手术并发症等临床资料。结果:患者21例中术前有6例为限制性上斜视,15例为限制性下斜视。手术中行上直肌断腱1例,后退5例,下直肌后退15例。术中发生巩膜损伤2例,其中1例在断肌止点时损伤巩膜,1例在将肌肉固定于巩膜上时缝穿巩膜;术中预置缝线滑脱3例;术后早期(术后1mo内)发生欠矫6例,过矫5例;术后晚期(术后6mo后)出现过矫15例,包括6例限制性上斜视患者、9例限制性下斜视;下睑退缩8例。结论:TAO限制性斜视手术矫正容易出现过矫,手术中应严格控制肌肉后退量,下直肌后退时应注意下睑退缩发生的可能。     

先天性和共同性斜视眼外肌病理变化的比较

目的观察先天性斜视、共同性斜视眼外肌的病理变化,探讨共同性斜视、先天性斜视等肌源性病变特点。方法对50例先天性斜视及共同性斜视患者行斜视矫正术,将截除的眼外肌标本及选取的2例正常眼外肌标本制作石蜡切片,行HE染色并置于光镜下观察眼外肌的病理特点。结果正常眼外肌标本未见纤维组织增生;先天性内、外斜视眼外肌标本显示出不同程度的眼外肌纤维化、玻璃样变及肌纤维变性、结构消失等改变,以先天性内斜视改变较为显著。共同性内、外斜视可见肌纤维体积减小、数量减少,排列紊乱,发病较早、手术年龄大的共同性斜视患者多可见肌肉部分萎缩、肌纤维间隙增宽,胶原含量增多等改变。结论先天性斜视会引起眼外肌纤维化等的改变,而共同性斜视也会出现轻度眼外肌病理性改变。     

Strabismus Complications from Local Anesthetics

Strabismus developing after retrobulbar or peribulbar anesthesia for both anterior and posterior segment eye surgery may be due to myotoxicity to an extraocular muscle from the local anesthetic agent. Initial paresis often causes diplopia immediately after surgery, but later progressive segmental fibrosis occurs, and/or hypertrophy of the muscle, producing diplopia in the opposite direction from the direction of the initial diplopia. The inferior rectus muscle is most commonly affected. Usually a large recession on an adjustable suture of the involved muscle(s) yields good alignment. Using topical anesthesia or sub-Tenon's anesthesia can avoid this complication.     

Isolated abscess of extraocular muscle in two young boys: Clinical and imaging features

PURPOSE: To report two cases of a cystic isolated extraocular muscle abscess in a young boy. METHOD: Case report. RESULTS: Two cases of young boys with a cystic isolated extraocular muscle abscess are described. Each presented as an inflammatory lesion in the orbit that had been stable for approximately three weeks. Neurodiagnostic imaging of the two cases revealed a cystic lesion in close proximity to an extraocular muscle. An ultrasound-guided aspiration of each lesion revealed material that, when cultured, grew Staphylococcus aureus . Both patients recovered with appropriate antibiotic therapy. No other systemic illness could be identified in either case. CONCLUSION: These cases illustrate that an isolated abscess involving an extraocular muscle may present like an inflammatory cyst even without any evidence of systemic illness. When evaluating and managing such lesions, the authors recommend the use of ultrasound-guided aspiration to avoid complications arising from delay in diagnosis and inappropriate treatment.     

Neuro-ophthalmologic complications of cataract surgery

Neuro-ophthalmologic complications from cataract surgery are uncommon and include central nervous system toxicity, binocular diplopia, traumatic optic neuropathy and ischemic optic neuropathy. Retrobulbar blocks may be accidentally injected into the subarachnoid space with diffusion to the brainstem. This leads to cardiovascular, respiratory, and mental status compromise. Most patients have complete recovery with adequate support. Post-operative, binocular diplopia may occur secondary to anisometropia or previously unrecognized misalignment. Periocular injection may cause paresis or fibrosis of extraocular muscles. Anterior or posterior ischemic optic neuropathy can occur in the first 6 weeks after cataract surgery with or without periocular injection. The risk to the other eye is high with subsequent contralateral cataract extraction. Post-operative vision loss associated with direct traumatic needle injury is recognized immediately. Therefore, an orbital MRI may be warranted for a patient with an optic neuropathy in the first 24 hours after cataract surgery using periocular anesthesia. If evidence of needle injury is present on neuroimaging, a trial of steroids should be considered.     

Neuro-ophthalmologic complications of cataract surgery

Neuro-ophthalmologic complications from cataract surgery are uncommon and include central nervous system toxicity, binocular diplopia, traumatic optic neuropathy and ischemic optic neuropathy. Retrobulbar blocks may be accidentally injected into the subarachnoid space with diffusion to the brainstem. This leads to cardiovascular, respiratory, and mental status compromise. Most patients have complete recovery with adequate support. Post-operative, binocular diplopia may occur secondary to anisometropia or previously unrecognized misalignment. Periocular injection may cause paresis or fibrosis of extraocular muscles. Anterior or posterior ischemic optic neuropathy can occur in the first 6 weeks after cataract surgery with or without periocular injection. The risk to the other eye is high with subsequent contralateral cataract extraction. Post-operative vision loss associated with direct traumatic needle injury is recognized immediately. Therefore, an orbital MRI may be warranted for a patient with an optic neuropathy in the first 24 hours after cataract surgery using periocular anesthesia. If evidence of needle injury is present on neuroimaging, a trial of steroids should be considered.     

Functional and Motor Outcomes of Strabismus Surgery for Chronic Isolated Adult Sixth Nerve Palsy

Abstract

Abducens nerve palsy is the most common acquired ocular motor nerve palsy in adults. Chronic cases of abducens palsy often require surgical intervention to relieve disabling diplopia. The goal of this study was to identify factors associated with surgical outcomes in isolated abducens palsy. Medical records of all adult patients from 1988 to 2012 with abducens palsies who underwent strabismus procedures were retrospectively reviewed. Motor alignment, extraocular motility, and sensory outcomes were recorded. Success was defined as absence of diplopia without prisms or face turn, vertical deviation ≤2 prism dioptres (PD), and horizontal deviation ≤10 PD. Eighty-one patients (age range: 20–86 years) met inclusion criteria. Success was achieved in 58% of patients. Final success rates for abducens palsy were 50% for neoplastic, 59% traumatic, 57% for microvascular/unknown, and 67% for other central nervous system causes (p?>?0.05). Patients with an underlying neoplastic or traumatic aetiology required more than one strabismus procedure more often than those with microvascular/idiopathic or other central nervous system causes (48% vs. 24%; p?=?0.03). For complete abducens palsies, patients who underwent Hummelsheim-type procedures had a higher success rate than those who underwent a full-tendon vertical rectus muscle transposition. (78% versus 35%; p?=?0.049). Success rates for strabismus procedures in patients with abducens palsies are similar across all aetiologies. Frequency of re-operation is higher among those patients with neoplastic or traumatic aetiologies for their abducens palsies. Hummelsheim-type procedures have a higher success rate for complete abducens palsies than full-tendon vertical rectus transpositions.     

先天性眼外肌纤维化综合征研究进展

先天性眼外肌纤维化综合征（CFEOM）是临床少见的先天性非共同性斜视,临床表现为非进展性限制性眼肌麻痹,可伴有上睑下垂,以往被认为是原发性眼外肌纤维化所致,最近神经病理学、神经影像学和分子遗传学的研究显示CFEOM的病因为神经源性,为一种颅神经异常支配性疾病。分别对不同类型的CFEOM的神经病理学、神经影像学和分子遗传学研究进展进行综述。     

银杏叶提取物金纳多治疗外伤性眼外肌麻痹

目的 观察银杏叶提取物金纳多对外伤性眼外肌麻痹的治疗效果.方法 68例（74眼）外伤性眼外肌麻痹分为两组,观察组应用金纳多注射液治疗,对照组给予传统的营养神经药物治疗,观察症状、体征改善的情况,比较两组的疗效.结果 观察组治愈率和有效率均明显高于对照组（x2=14.51,9.86,P＜0.05）.结论 应用金纳多注射液治疗外伤性眼外肌麻痹,提高了治愈率.     

眼外肌肥大的影像学诊断意义

目的总结眼外肌肥大的病因，并对影像学检查的诊断价值进行探讨。方法对249例CT或MRI检查显示眼外肌肥大的病例进行回顾性分析，并对病因进行分析和分类。结果炎症、血管畸形、肿瘤、感染、外伤等皆可是眼外肌肥大的病因。导致眼外肌肥大的疾病按发病率由高到低依次为甲状腺相关眼病、眼眶炎性假瘤、颈动脉海绵窦瘘、眶蜂窝织炎、转移性肿瘤、静脉曲张、眶骨骨折等。甲状腺相关眼病的哏外肌肥大以肌腹肥大为主，肌腱止点一般正常。炎性假瘤受累肌肉呈不规则增粗，边缘模糊，病变大多累及肌肉的止点。颈动脉海绵窦瘘通常为单眼眼外肌呈弥漫梭形肥厚。结论影像学检查包括CT和MRI扫描能够揭示眼外肌肥大的病因特征，并可作为鉴别诊断的依据。     

斜视青少年手术后眼表及睑板腺功能特征变化及影响因素分析

目的:探究斜视青少年手术后眼表及睑板腺功能特征变化,并分析相关影响因素。方法:回顾性研究。选取2019-01/12在我院行斜视手术的患儿168例224眼作为研究对象。根据手术切口将分为角膜缘切口组(A组,54例78眼),跨肌止端切口组(B组,48例62眼),近穹窿切口组(C组,66例84眼)。根据手术累及肌肉条数分为单条眼外肌组(68眼),双条眼外肌组(106眼)及三条眼外肌组(50眼)。评估患儿眼表健康状况,并采用LipiView眼表干涉仪等分析泪膜脂质层厚度(LLT)、泪河高度(TMH)、角膜荧光素染色评分(CFSS)、泪膜破裂时间(TBUT)、泪液分泌试验(SⅠt)和睑板腺开口情况。结果:术后1wk,三组患儿眼表及睑板腺功能均无明显差异。术后1mo,不同手术切口及手术累积不同肌肉条数患儿眼表及睑板腺功能均有明显改善(P<0.05),其中B组患儿TBUT明显高于A组(P<0.05),C组患儿的OSDI、CFSS、TBUT显著优于A组(P<0.05);且双条组患儿TMH显著高于单条组(P<0.05),三条组患儿的OSDI高于单条组(P<0.05)。术后3mo,各组患儿眼表及睑板腺功能均较术后1wk,1mo有显著改善(P<0.05);其中,C组患儿的OSDI、LLT、TMH、CFSS、TBUT及SⅠt均显著优于A组(P<0.05);双条组患儿TMH、CFSS、SⅠt及睑板腺开口情况均优于三条组,但差异无统计学意义(P>0.05),而双条和三条组患儿睑板腺开口评分低于单条组(P<0.05)。患儿OSDI、CFSS及睑板腺开口评分与手术累及肌肉数呈显著相关(P<0.05)。结论:近穹窿切口组患儿眼表及睑板腺功能恢复优于采用角膜缘切口组及跨肌止端切口组;且单条组患儿眼表及睑板腺功能恢复优于双条组及三条组患儿。采取的近穹窿切口,减少手术累及肌肉数,有利于青少年斜视术后眼表及睑板腺功能的恢复。