From the Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India.
The authors have no financial or proprietary interest in the materials presented herein.
Address correspondence to Rohit Saxena, MD, Room No. 485, Fourth Floor, Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India 110029.
Post-traumatic inferior rectus muscle disinsertion can result in a marked vertical tropia and can be difficult to manage. Surgical modalities that have been described include exploration and reinsertion of the muscle, resection of the remaining muscle or fibrous tissue combined with recession of the ipsilateral superior rectus muscle,1 inferior transposition of the horizontal recti muscle,2 and transposition of the inferior oblique muscle tendon to the inferior rectus muscle.3 Unfortunately, none of these methods yields predictable and consistent results. We describe a new technique of anchoring the globe to the floor of the orbit along with supramaximal recession of the ipsilateral superior rectus muscle for large-angle hypertropia in a case of post-traumatic inferior rectus palsy.
A 30-year-old man presented complaining of upward deviation of the right eye along with loss of vision following a history of trauma to the right eye with an iron rod 12 years previously. On examination, visual acuity was counting fingers in the right eye and 20/20 in the left eye. There was right hypertropia amounting to 30° and marked underaction of the inferior rectus muscle with ectropion of the lower eyelid in the right eye. The rest of the ocular movements were normal (Fig. 1). Fundus examination revealed primary optic atrophy in the right eye. Computed tomography scanning of the orbit was done and showed upward rotation of the right eyeball, but the belly of the inferior rectus muscle could not be clearly identified.
Figure 1. Preoperative Photograph Showing Hypertropia in the Right Eye Along with Severe Underaction of Inferior Rectus Muscle and Ectropion of the Right Lower Eyelid.
After obtaining informed written consent, the patient underwent surgery under general anesthesia. Results of the forced duction test (FDT) were moderately positive and the globe could be depressed just below the midline. Recession of the superior rectus muscle (12 mm) was performed in a conventional manner to free the muscle.
Using a fornix-based conjunctival incision, the inferior rectus muscle was hooked. At the insertion, the muscle was found to be severely lacerated and only the sheath was retrieved (Fig. 2A). Blunt dissection was done by extending the same incision and the periosteum of the orbital floor was exposed (Fig. 2B). A titanium plate was bent at 90º at one end (Fig. 2C) and a silicone band was secured through one of the holes at the other end of the plate with 4-0 Prolene sutures (Johnson and Johnson, Ltd., Aurangabad, India). The bent end of the plate was then fixed at the outer aspect of the orbital rim using titanium screws so that the longer part of the plate with the attached silicone band would be parallel to the orbital floor (Fig. 2D).
Figure 2. Surgical Steps. (A) Lacerated Inferior Rectus Muscle at the Insertion. (B) Exposure of the Inferior Orbital Rim. (C) Titanium Plate; Note the Superior Bent End of the Plate. (D) Titanium Plate Fixed to the Inferior Orbital Rim Along with the Pre-Fashioned Silicone Band. (E) Diagram Representing the in Situ Placement of the Plate and the Silicone Band. Note that the Vector Generated by the Pull of the Silicone Band Is Directed Inferiorly and Posteriorly.
Two single-armed 4-0 Prolene sutures were passed through the free end of the band and were anchored to the globe at the insertion site of the inferior rectus muscle. Before tying the final knot, the position of the globe was aligned at the primary position. The conjunctival incision was closed with 8-0 Vicryl sutures (Johnson and Johnson, Ltd.).
Postoperatively, the patient received topical antibiotic steroid drops along with systemic anti-inflammatory medication. Following surgery, the eye was vertically aligned in the primary position with hypertropia of 8 prism diopters with mild residual exotropia (Fig. 3).
Figure 3. Postoperative Photograph Showing Marked Decrease in Amount of Vertical Deviation.
The patient presented with inferior rectus muscle palsy after trauma to the orbital floor. Absence of active force generation test preoperatively was indicative of either severe damage or complete disinsertion of the muscle. Other surgical options were considered for the patient before finally opting for the mentioned procedure. Although resection of the muscle with or without combined recession of its antagonist is a viable option, it is only successful in cases where the muscle has some residual force.1 Another option includes transposition of the horizontal recti to the inferior rectus muscle.2,4 However, the fact that the inferior rectus muscle was disinserted and its vascular supply to the anterior segment was lost, combined with the need to perform a superior rectus recession to make the FDT negative, meant the risk of anterior segment ischemia was high.5 Therefore, further compromise of the vascular supply by transposing the horizontal recti muscles was not considered a reasonable option. Anterior transposition of the inferior oblique muscle has been described in a case of snapped inferior rectus muscle.3 The procedure can induce intorsion due to unopposed action of the superior oblique muscle, and we believed it might not generate the adequate depressive force required in this case. Thus, we believed that in our case none of the above-mentioned options could give satisfactory results on their own. In a recent case report,6 the authors performed staged surgery on all of the extraocular muscles to achieve the desired result but did not report anterior segment ischemia; nevertheless, the risk is present at all times.
The technique of anchoring the globe to the orbital wall has gained popularity in recent years. The authors have successfully used the procedure in cases of complete third nerve palsy.7 Various methods of anchoring the globe either directly with nonabsorbable sutures7,8 or with the help of a silicone band,9 fascia lata,10 and muscle tendon11 or through bone anchor screw12 have been described.
In our case, we fixed the globe to the floor of the orbit with a silicone band and titanium orbital plate. A silicone band is not only biocompatible, but it also has a good tensile strength to bear the tension and therefore has been used regularly in ocular and strabismus surgery. A titanium plate is commonly used for the repair of orbital floor fracture because it is biocompatible and produces minimal soft tissue reaction.13 The plate was bent at 90° at one end and was directed toward the floor. This directed the vector of the force generated by the pull of the silicone band inferiorly and posteriorly, similar to the physiological force generated by the inferior rectus muscle (Fig. 2E). Postoperatively, the vertical deviation decreased to 8 prism diopters, but there was residual exotropia that will have to be dealt with later.
The limitation of movements is the major disadvantage of the anchoring procedure and in our case both superior and inferior movements were limited. Eyelid retraction is often associated with disinsertion of the inferior rectus muscle14 and requires surgical correction.
Inferior anchoring of the globe has the potential to be an effective alternative to transposition procedures in cases of severe paralysis or complete disinsertion of the inferior rectus muscle and is devoid of the risk of anterior segment ischemia. The additional advantage is that the surgery can be done in conjunction with the repair of associated orbital floor fracture. The major disadvantage of the procedure is limitation of the superior movement of the globe. The technique needs to be refined and long-term follow-up is required to evaluate its viability.
- Partik G, Harrer S, Rossmann M, Brandstetter M, Ettl A. Avulsion of the inferior rectus muscle due to a dog-bite and reconstruction of its function. Klin Monatsbl Augenheilkd. 2001;218:810–813. doi:10.1055/s-2001-19693 [CrossRef]
- Kowal L, Wutthiphan S, McKelvie P. The snapped inferior rectus. Aust N Z J Ophthalmol. 1998;26:29–35.
- Aguirre-Aquino BI, Riemann CD, Lewis H, Traboulsi EI. Anterior transposition of the inferior oblique muscle as the initial treatment of a snapped inferior rectus muscle. J AAPOS. 2001;5:52–54. doi:10.1067/mpa.2001.111014 [CrossRef]
- Burke JP, Keech RV. Effectiveness of inferior transposition of the horizontal rectus muscles for acquired inferior rectus paresis. J Pediatr Ophthalmol Strabismus. 1995;32:172–177.
- Saunders RA, Bluestein EC, Wilson ME, Berland JE. Anterior segment ischemia after strabismus surgery. Surv Ophthalmol. 1994;38:456–466. doi:10.1016/0039-6257(94)90175-9 [CrossRef]
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- Bicas HE. A surgically implanted elastic band to restore paralyzed ocular rotations. J Pediatr Ophthalmol Strabismus. 1991;28:10–13.
- Salazar-Leon JA, Ramirez-Ortiz MA, Salas-Vargas M. The surgical correction of paralytic strabismus using fascia lata. J Pediatr Ophthalmol Strabismus. 1998;35:27–32.
- Villasenor Solares J, Riemann BI, Romanelli Zuazo AC, et al. Ocular fixation to nasal periosteum with a superior oblique tendon in patients with third nerve palsy. J Pediatr Ophthalmol Strabismus. 2000;37:260–265.
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