Journal of Pediatric Ophthalmology and Strabismus

Short Subjects 

Challenging Surgical Approach to a Lost Inferior Rectus Muscle Following Penetrating Orbital Trauma

Andreas Di-Luciano, MD; David Hunter Cherwerk, MD; Jerson Diaz, MD; Luis Tanaka; Daniel E. Neely, MD; Andrea Molinari, MD

Abstract

A 37-year-old man suffered a penetrating left orbital injury with rupture of the inferior rectus muscle and avulsion of the optic nerve. The orbit was explored and the inferior rectus muscle stump was identified 25 mm from the limbus. Despite this, the muscle was successfully reattached and the patient achieved satisfactory postoperative alignment. [J Pediatr Ophthalmol Strabismus. 2019;56:e49–e52.]

Abstract

A 37-year-old man suffered a penetrating left orbital injury with rupture of the inferior rectus muscle and avulsion of the optic nerve. The orbit was explored and the inferior rectus muscle stump was identified 25 mm from the limbus. Despite this, the muscle was successfully reattached and the patient achieved satisfactory postoperative alignment. [J Pediatr Ophthalmol Strabismus. 2019;56:e49–e52.]

Introduction

A Peruvian farmer suffered a severe penetrating left orbital injury with complete rupture of the inferior rectus muscle and avulsion of the optic nerve. The orbit was explored and the inferior rectus muscle stump was identified 25 mm from the limbus. Despite this, the muscle was successfully reattached and the patient achieved satisfactory postoperative alignment.

Case Report

A 37-year-old man suffered a penetrating left orbital injury with a metal rod while working in the fields. He recalls bumping into the exposed rod and noticing bleeding and loss of vision in his left eye shortly thereafter. The patient was first treated at a local hospital, and the operative report indicated that the inferior rectus muscle was ruptured and the distal stump (attached to the globe) was “sutured into the inferior fornix.” The proximal stump (orbital) of the inferior rectus muscle could not be visualized. Ten months later, the patient presented to a tertiary level hospital for further care and remote consultation with an Orbis Volunteer Faculty member (AM) using the Orbis Cybersight telemedicine program. The examination at this time found visual acuities of 20/20 in the right eye and no light perception in the left eye. The vertical deviation was approximately 90 prism diopters (PD), but it was virtually unmeasurable because the hypertropic left eye was mostly covered by the upper eyelid and there was a severe limitation to depression (Figure 1). A conjunctival scar was clearly visible in the inferior fornix.

Motility photographs taken 10 months after the accident and submitted for Orbis Cybersight telemedicine consultation. Note severe limitation to depression in the left eye.

Figure 1.

Motility photographs taken 10 months after the accident and submitted for Orbis Cybersight telemedicine consultation. Note severe limitation to depression in the left eye.

A computed tomography (CT) scan of the brain and orbits ordered during the telemedicine consultation process was available for review. The sagittal cuts of the CT scan demonstrated that the optic nerve was severed from the globe and displaced superiorly, localized just beneath the superior rectus muscle. The proximal orbital stump of the inferior rectus muscle could also be identified and was located close to the normal insertion of the optic nerve. (Figure 2)

The optic nerve was severed from the globe and displaced superiorly. The proximal orbital stump of the inferior rectus muscle was located close to the normal insertion of the optic nerve.

Figure 2.

The optic nerve was severed from the globe and displaced superiorly. The proximal orbital stump of the inferior rectus muscle was located close to the normal insertion of the optic nerve.

Although the eye clearly had no visual potential, the patient desired reconstructive surgery because his daily life was severely affected by his appearance. During a subsequent Orbis Flying Eye Hospital program in conjunction with the same tertiary care hospital in Peru, the patient was evaluated in person by the same Orbis volunteer faculty member who had assisted with his telemedicine consultation. After confirmation of examination findings, a surgical plan was made to explore the left orbit and to attempt retrieval of the remaining fibers of the proximal inferior rectus muscle, along with completion of any other necessary strabismus surgery repair.

Intraoperatively, forced ductions demonstrated significant restriction to ocular rotations, particularly depression. The bulbar conjunctiva on the lower half of the globe was completely adherent to the sclera. An inferior fornix incision was performed after injecting a mixture of xylocaine, bupivacaine, and epinephrine beneath the conjunctiva and Tenon's layers for hemostasis and hydrodissection. Significant cicatricial fibrosis was present, but with careful dissection some muscle fibers from the inferior rectus muscle could be recognized attached to the sclera approximately 25 mm from the limbus. These fibers were secured with a 5-0 non-absorbable, braided polyester suture and disinserted from the globe. Remnants of the optic nerve sheath could also be recognized an additional 4 mm behind the insertion of these inferior rectus muscle fibers.

The superior rectus muscle was then identified and secured with a standard double-armed 6-0 absorbable braided polyglactin suture and the muscle was disinserted from the globe. Once the restricted muscle was disinserted, passive ductions, particularly depression, improved significantly. The inferior rectus muscle fibers were then sutured back to the sclera as anteriorly as possible, approximately 15 mm from the limbus. The superior rectus muscle was allowed to hang back a dramatic 20 mm from its original insertion.

On the first postoperative day, ductions of the left eye had significantly improved with full vertical excursions and an essentially orthotropic alignment by corneal light reflex testing. At the 6-week postoperative follow-up, there was a mild limitation to depression of the left eye but horizontal ductions remained full (Figure 3). Alignment with the Krimsky technique showed approximately 20 PD of exotropia and 15 PD of left hypertropia, but the patient remained extremely satisfied with the result (Figure 4).

The first postoperative day. The patient was orthotropic by corneal light reflex and had improvement of depression and full horizontal movements.

Figure 3.

The first postoperative day. The patient was orthotropic by corneal light reflex and had improvement of depression and full horizontal movements.

At 6 weeks postoperatively, the patient had 15 prism diopters (PD) of residual left hypertropia and 20 PD of exotropia, but was happy with this result.

Figure 4.

At 6 weeks postoperatively, the patient had 15 prism diopters (PD) of residual left hypertropia and 20 PD of exotropia, but was happy with this result.

Discussion

Repairing a damaged, avulsed, or ruptured extraocular muscle is a challenging problem in strabismus surgery. Information is typically lacking or uncertain, but preoperative high-resolution orbital imaging with CT or magnetic resonance imaging is helpful in predicting the location and status of the damaged muscle segments.1–3 In the current study, the Orbis Cybersight telemedicine consultation and resulting CT scan were helpful in locating the proximal stump of the inferior rectus muscle and facilitated the planning of an appropriate treatment strategy.

Although magnetic resonance imaging provides the best quality images to assess the structural condition of a damaged extraocular muscle, CT scans are the fastest and most widely available high-resolution imaging modality for patients with orbital trauma, particularly in developing countries, such as the case with this patient. Axial, coronal, and sagittal images may be quickly obtained through the orbital region and are particularly helpful when fractures or foreign bodies are involved.

Proper surgical technique by a skilled and experienced strabismus surgeon is important for successful early or late recovery and repair of transected extraocular muscles. Many suspected transected muscles are at least partly intact and gentle exploration of their possible locations should be attempted first before deciding on a transposition procedure.4 A limbal approach is usually preferred for this kind of complex surgery because it allows maximum exposure with only gentle tissue traction. It is critical to maintain excellent operative hemostasis and have good lighting and magnification available. The help of a capable second surgeon is often essential and greatly facilitates these deep tissue dissections.5 If the patient has not received anticholinergic drugs (eg, atropine or similar medications), tugging on the muscle may help differentiate it from the surrounding tissue by inducing the oculocardiac reflex.6

If the avulsed ends of damaged rectus muscle cannot be located despite visualizing them on preoperative imaging, it may be useful to attempt repair again at a later date when orbital inflammation has decreased.7 It is rarely advisable to perform a transposition procedure at the time of acute injury and presumed extraocular muscle loss.8,9 Some muscle function is frequently present from residual intact muscle or develops during the healing process by spontaneous readhesion of the muscle or through adjacent intermuscular septal attachments, allowing a more experienced surgeon to recover the muscle at a later time for a better result and less risk for anterior segment ischemia.

The decision to treat our patient with no visual potential was based on the psychological and social problems he was suffering. The presence of manifest strabismus adversely affects many aspects of patients' lives, including finding a partner, job prospects, and interaction with peers, and it may manifest more seriously as psychiatric disorders.10

References

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  2. Çagatay HH, Ekinci M, Ulusal S, Oba ME, Yazar Z. Inferior rectus muscle rupture. Nepal J Ophthalmol. 2015;7:182–185. doi:10.3126/nepjoph.v7i2.14976 [CrossRef]
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  7. Del Monte MA. Management of direct extraocular muscle trauma. American Orthoptic Journal. 2004;54:32–44. doi:10.3368/aoj.54.1.32 [CrossRef]
  8. Olitsky SE, Notaro S. Anterior transposition of the inferior oblique for the treatment of a lost inferior rectus muscle. J Pediatr Ophthalmol Strabismus. 2000;37:50–51.
  9. Paysee EA, Saunders RA, Coats DK. Surgical management of strabismus after rupture of the inferior rectus muscle. J AAPOS. 2000;4:164–167. doi:10.1016/S1091-8531(00)70007-3 [CrossRef]
  10. Durnian JM, Noonan CP, Marsh IB. The psychosocial effects of adult strabismus: a review. Br J Ophthalmol. 2011;95:450–453. doi:10.1136/bjo.2010.188425 [CrossRef]
Authors

From Flying Eye Hospital, Orbis, New York, New York (AD-L, DHC); Instituto Regional de Oftalmología, Trujillo, Perú (JD, LT); Indiana University School of Medicine, Indianapolis, Indiana (DEN); Orbis Cybersight, Orbis International, New York, New York (DEN); and Universidad Central del Ecuador, Hospital Metropolitano, Quito, Ecuador (AM).

The authors have no financial or proprietary interest in the materials presented herein.

Correspondence: Daniel E. Neely, MD, 1160 W. Michigan St., Eugene and Marilyn Glick Eye Institute, Indianapolis, IN 46202. E-mail: deneely@iu.edu

Received: March 25, 2019
Accepted: April 03, 2019
Posted Online: July 05, 2019

10.3928/01913913-20190509-02

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