Complete inferior rectus muscle transection secondary to orbital blowout fracture

Complete extraocular muscle transection is uncommon in the setting of blunt trauma. We report a case of a 53-year-old male that developed diplopia after hitting his face directly on a concrete slab after a fall. On examination, he had a right hypertropia with a complete infraduction deficit. A CT scan of the face showed an orbital floor blowout fracture with complete inferior rectus transection. On surgical exploration, the distal and proximal ends of the muscle were identified and sutured together, and the floor fracture was repaired. At his post-operative visits, the patient had a persistent infraduction deficit, but subjectively had improved diplopia.     

Inferior rectus muscle entrapped by Teflon implant after orbital floor fracture repair

A patient with a tripod fracture had entrapment of the inferior rectus muscle after reconstruction of an orbital floor defect with an alloplastic implant. Prior to insertion of the implant, the operating surgeon reported no motility disturbance. An orbital computed tomography scan suggested that the implant impinged on the inferior rectus muscle. Because of persistent diplopia, the orbit was reexplored. An intraoperative forced duction test prior to removal of the implant was positive in the field of action of the inferior rectus muscle. An intraoperative forced duction test after removal of the implant was negative in the field of action of the inferior rectus muscle. Motility was markedly improved after removal of the implant. These findings confirm that the implant was the cause of the entrapment. The surgical technique utilized to minimize complications after orbital floor reconstruction with the implant is outlined in this article.     

Traumatic tear of the inferior rectus muscle treated with inferior oblique anterior transposition

Purpose To report a case of traumatic tear of the inferior rectus muscle treated with inferior oblique anterior transposition (IOAT). Methods Case report of a 55-year-old man who presented with vertical diplopia (VD) after orbital trauma. Ocular examination disclosed a 62PD right hypertropia (RHT) in the primary position (PPO). The right inferior rectus (RIR) was torn, and the distal stump was fixed to the skin with tape. Results Surgery was performed under local anesthesia. The RIR tearing occurred 13 mm from the insertion, and exploration revealed its proximal end. The right inferior oblique (RIO) was intact, although its fibers were loose. Since the RHT did not improve following reattachment of the proximal and distal stumps of the RIR, the distal stump was excised and the proximal end brought forward and sutured 6.5 mm from the limbus. At perioperative evaluation, there was a 25PD RHT in PPO where the VD persisted. The RIO was subsequently isolated, detached, and its distal end, after 6 mm resection, was sutured to a point temporal to the lateral border of the RIR. The patient was reevaluated and had neither RHT nor VD in primary gaze. At the 6-week postoperative evaluation, he was orthotropic in PPO, complaining about diplopia only on extreme downgaze. A mild limitation of right depression was observed. The patient was satisfied with the surgical results and experienced no functional limitations during any activities. Conclusion IOAT can provide acceptable binocular visual function without the risk of anterior segment ischemia in cases of torn inferior rectus muscle. This work should be attributed to the University of Mogi das Cruzes.     

Pediatric orbital floor fracture : direct extraocular muscle involvement

OBJECTIVE: To study the clinical presentation, operative findings, and postoperative results of a surgical series of isolated orbital floor fractures in children. DESIGN: Noncomparative, retrospective, consecutive case series. PARTICIPANTS: Thirty-four patients (34 orbits) less than 18 years of age with isolated orbital floor fractures. Indications for surgery were severe limitation of extraocular ductions, 22 of 34; enophthalmos, 8 of 34: or both, 4 of 34. INTERVENTION: Surgical repair. MAIN OUTCOME MEASURES: Cause of fracture, symptoms, clinical signs, radiographic data, operative findings, postoperative results, and complications. RESULTS: Children older than 12 years of age were more likely to sustain an orbital floor fracture as a result of interpersonal violence than were children less than 12 years of age (P: = 0.020). Sixty-two percent of patients (21 of 34) exhibited pain with eye movements and/or nausea and vomiting. Most had a trapdoor type fracture (21 of 34). The inferior rectus muscle was entrapped in the orbital floor fracture in 69% (18 of 26) of patients with a severe limitation of ocular ductions. Preoperative nausea and vomiting were immediately relieved after surgery. The median time for improvement of preoperative duction deficits and diplopia was 4 days for patients receiving surgery within 7 days and 10.5 days for those undergoing surgery after 14 days (P: = 0.030). Resolution of duction deficits or diplopia was not dependent on time of surgery if performed within 1 month of injury. Loss of vision, worsening of motility, or implant complications did not occur. CONCLUSIONS: Pediatric patients with isolated orbital floor fractures who had pain, nausea, vomiting, and severe limitation of extraocular motility often have direct entrapment of the inferior rectus muscle into the fracture site. Surgical repair rapidly relieved preoperative pain, nausea, and vomiting. For patients with severe limitation of ductions, early surgical repair within 7 days of injury resulted in more rapid improvement of ductions and diplopia than surgery performed later.     

An orbital hydatid cyst involving inferior rectus muscle: A case report

The orbital hydatid cyst is a rare entity and although most of them are located in superolateral and superomedial angles of orbits, involvement of inferior sites is uncommon. We report a 12-year-old case of primary hydatid cyst situated in inferior rectus muscle which was undergone surgical removal. Magnetic resonance imaging (MRI) was used for differential diagnosis of hydatid cyst. Moreover, histological analysis was performed, after the cyst removal, to confirm the diagnosis. Early clinical and radiological evaluations and subsequent surgical excision is the mainstay of treatment and should be performed to prevent severe complications caused by the advanced and ruptured cysts.

Abbreviations: MRI: magnetic resonance imaging; CNS: central nervous system; BCVA: best corrected visual acuity; CT: computed tomography; USG: ultrasonography     

Adult medial orbital wall trapdoor fracture with missing medial rectus muscle

We report the case of a 28-year-old man presenting with a medial orbital wall trapdoor fracture with a missing medial rectus muscle. We believe this to be the first case report of an adult medial orbital wall trapdoor fracture. Trapdoor fractures most commonly occur in the pediatric population, and those involving the medial orbital wall generally occur in areas with less developed ethmoid air cells. Since the present case followed neither pattern, a different injury mechanism was considered. The ethmoid air cells in this case were well developed, which may have played an important role in the pathogenesis of this adult medial orbital wall trapdoor fracture. Based on our findings, we propose a possible mechanism for a medial orbital wall trapdoor fracture in an adult. The cellular frames enable the medial bone to shift just minimally, regardless of the high orbital pressure during a blow. The excess volume of the orbital content escapes into the cells through narrow cracks; therefore, after a blow, it cannot move back completely into the orbit. Consequently, it pushes the shifted bone towards the orbit, becoming trapped in a manner similar to that of a check-valve mechanism.     

Anteriorization of inferior oblique muscle and downward transposition of medial rectus muscle for lost inferior rectus muscle

A 6-year-old boy who had been treated with bilateral medial rectus muscle recessions 3 years earlier for congenital esotropia was undergoing bilateral inferior oblique muscle recessions to correct inferior oblique muscle overaction. The right inferior rectus muscle was inadvertently cut during this surgery and was irretrievable. To manage this complication, the medial rectus muscle was transposed toward the inferior rectus insertion and the inferior oblique muscle was anteriorized. At the 1 year follow-up visit, no infraduction deficit was present on downgaze and only 8(delta) of left hypertropia was present in primary position.     

Congenital absence of the inferior rectus muscle

A case of unilateral congenital absence of the inferior rectus muscle is presented. Absences of extraocular muscles, either singly or in combination, are rare, but isolated reports have been published. The abnormalities have been reported as occurring with increased frequency in craniofacial dysostoses, notably Crouzon's disease. In the case reported here, the abnormality was discovered during planned vertical muscle surgery for a large left hypertropia. Infraplacement of the horizontal recti was performed at a later date. Computerised axial tomography (CAT) scanning confirmed the absence of the inferior rectus. The embryogenesis of the extraocular muscles is briefly discussed.     

伴或不伴下直肌箝闭的trapdoor眼眶骨折的临床特征

目的　研究伴或不伴有下直肌箝闭的ｔｒａｐｄｏｏｒ眶底骨折的临床特征。方法　回顾性分析２００８年１月至２０１５年１２月在深圳市眼科医院确诊为ｔｒａｐｄｏｏｒ眶底骨折并行眼眶壁骨折整复术的２０例儿童和青年患者的临床资料,根据ＣＴ图像和术中所见将患者分为两组:伴或不伴有下直肌箝闭组。对两组术前术后的症状、ＣＴ图像、手术记录和随访结果进行比较。结果　不伴下直肌箝闭组的年龄、就诊时间和手术时间分别为（８．９１±５．３２）岁、（７．６４±８．２４）ｄ、（９．００±８．３９）ｄ,伴下直肌箝闭组分别为（１２．４４±４．６９）岁、（９．５６±６．６２）ｄ、（１０．７８±６．４４）ｄ,两组相比差异均无统计学意义（均为Ｐ＞０．０５）。但伴有下直肌箝闭的ｔｒａｐｄｏｏｒ眼眶骨折表现为严重的眼球上转受限－３．８９±０．３３、明显下转受限－２．４４±０．７３和严重的被动上转受限－４。而不伴有下直肌箝闭者表现为轻至中度上转受限－１．９１±０．３０、轻度被动上转受限－１．０９±０．３０。除了伴或不伴有下直肌箝闭外,二组其他ＣＴ图像相似。结论　伴有严重的眼球上转受限、中度及以上眼球下转受限,及严重的被动上转受限的ｔｒａｐｄｏｏｒ眼眶骨折提示有下直肌箝闭。轻至中度眼球上转受限和轻度被动上转受限,下转无明显受限者提示仅为脂肪结缔组织嵌顿。     

Force necessary to fracture the orbital floor

Current thought on the pathophysiology of orbital wall fractures postulates either a "hydraulic" or a "buckling" mechanism. Evidence from cadaver, dried skull, and theoretical model studies supports both theories. No in vivo data, human or nonhuman primate, are available that quantitate the force necessary to fracture the orbital floor by either of the two mechanisms. We developed an apparatus that delivers quantifiable force only to the globe, without occluding the orbital opening or striking the orbital rim. We used it on 11 anesthetized Macaca fascicularis monkeys. Following a single bilateral application, the orbits were exenterated, and the orbital walls and orbital contents were examined to determine the extent of injuries. Fractures were described, diagrammed, and photographed. Fracture of the orbital floor was consistently produced at and above a force of 2.08 J. Posterior ruptures of five eyes occurred over the same range. We provide the first accurate measurements of the force required to produce orbital blow-out fractures in a live primate model. We show that orbital floor fractures can occur at low energies with direct ocular trauma only ("pure" hydraulic mechanism). Orbital wall fractures failed to protect the globe from rupture in 23% of cases.     

Spontaneous orbital haemorrhage into the lateral rectus muscle

BACKGROUND: Spontaneous orbital haemorrhage can occur at any age. The clinical presentation is often dramatic with acute painful proptosis and nausea. Vision may be severely impaired. HISTORY AND SIGNS: A 77 years old lady woke up with sudden retroocular pain, diplopia and proptosis. Her blood pressure was 235 / 95 mmHg. MRI showed a right retroocular mass, contiguous with the lateral rectus muscle and consistent with a haemorrhage. Vision was preserved in both eyes but the right visual field slightly altered. Motility of the right eye was severely impaired. THERAPY AND OUTCOME: The risks of surgical drainage were considered too high in a case of only slight visual field impairment, and a conservative attitude was decided. Evolution was good with antihypertensive treatment, the haemorrhage resorbed and diplopia improved. MRI showed no morphological orbital anomaly. CONCLUSIONS: Spontaneous orbital haemorrhage is a complication of a vascular orbital anomaly in most cases, more rarely due to a disturbance of coagulation. In our case arterial hypertension in association with antiaggregant intake explains the haemorrhage. Conservative treatment appears adequate with regard to the only slight visual field impairment. Close neuro-ophthalmological follow-up is, however, needed.     

眶下壁骨折早期手术治疗13例报告

目的探讨眶下壁骨折眼球内陷的治疗方法及疗效。方法13例（13眼）早期经上颌窦（柯-陆式）手术进路，碘仿纱条填塞。结果11例眼球内陷被矫正，1例眼球内陷有所改善，1眼无效。结论眶下壁骨折眼球内陷，早期经上颌窦进路复位重建疗效良好。     

爆裂性眶壁骨折45例临床分析

３年来我院治疗爆裂性眶臂骨折４５例，其中手术治疗３９例，非手术治疗６例，全愈２８例（６２％），好转１３例（２９％）不变４例（８．９％Ｏ。文章对手术适应证，手术方法进行了讨论，并对术后残留复视的原因进行了分析。