Traumatic rupture of the superior oblique tendon is a rare cause of acquired Brown’s syndrome. This report describes a case of traumatic rupture of the superior oblique tendon, distal to the trochlea, after injury with a plant hook. The ruptured tendon was reapproximated. Postoperatively, asymptomatic Brown’s syndrome developed, although residual function of the superior oblique muscle was retained. Full-thickness upper eyelid lacerations, especially those caused by a hook, must be explored carefully to exclude superior oblique tendon rupture. Careful reapproximation of the tendon can result in residual muscle function.
From the South Australian Institute of Ophthalmology and the Department of Ophthalmology & Visual Sciences, University of Adelaide, South Australia, Australia.
The authors have no financial or proprietary interest in the materials presented herein.
Address correspondence to Sunil Warrier, MBBS, Department of Ophthalmology & Visual Sciences, Royal Adelaide Hospital, North Terrace, Adelaide, South Australia 5000, Australia.
Received: September 09, 2007
Accepted: April 29, 2008
Posted Online: August 10, 2009
Eyelid lacerations are a common emergency department presentation requiring ophthalmological assessment. Many of these cases can be assessed and managed in the clinic or emergency department under local anasthesia. Whenever globe injury or periocular or adnexal damage is suspected, the controlled environment of the operating department is preferred. We present a case of a medial upper eyelid laceration with extraocular muscle involvement.
A 36-year-old woman had a traumatic injury to the eyelid after a collision with a hanging plant hook while working in her shade house. She presented to the emergency department and was found to have a laceration of the right upper eyelid. Examination showed a full-thickness vertical laceration of the medial right upper eyelid that involved the eyelid margin and appeared to enter the orbit (Fig. 1). Visual acuity was 6/6 in both eyes, and findings on intra-ocular examination were unremarkable. Extraocular movements could not be evaluated in the emergency department, and the patient did not complain of diplopia. She was systemically well and therefore was taken to the operating room for exploration and repair. During surgery, a white structure was noted in the superonasal quadrant. Further exploration showed that the white structure was the ruptured tendon of the right superior oblique muscle (Fig. 2), distal to the trochlea (Fig. 3). The cut ends of the tendon were reapproximated with 6-0 polyglactin sutures.
Figure 1. Clinical Photograph Showing Full-Thickness Laceration of the Right Upper Eyelid.
Figure 2. Intraoperative Photograph Showing Traction on the Tendon of the Superior Oblique Muscle Resulting in Depression of the Eye.
Figure 3. (A) Intraoperative Photograph Showing Eyelid Laceration with the Ruptured Superior Oblique Muscle Tendon Distal to the Trochlea (arrow) (tendon Secured with Suture). (B) Diagram Showing the Site of Tendon Rupture Distal to the Trochlea.
On follow-up 1 week postoperatively, the patient showed minimal diplopia in all positions of gaze and partial restriction of elevation in adduction. One month postoperatively, the patient had diplopia only in levoelevation. Examination of extraocular movements showed absence of elevation in adduction of the right eye (Fig. 4), with preserved elevation in primary position and abduction, characteristic of Brown’s syndrome. She retained limited function of the right superior oblique muscle, as evidenced by limited intorsion and depression in adduction. Alternate prism-and-cover testing showed orthotropia in primary position, and 4° right incyclotropia was detected on synoptophore examination. Because no diplopia was present in primary position or down gaze, it was decided to observe her progress, and the patient remained asymptomatic at 6-month follow-up.
Figure 4. Postoperative Clinical Photograph Showing Traumatic Brown Syndrome Evidenced by Limited Elevation in Adduction.
Traumatic injury of the superior oblique muscle tendon is the rarest of extraocular muscle injuries, with only four reported cases.1–3 In 1974, Knapp4 described two cases of traumatic superior oblique palsy resulting in pseudo-Brown syndrome caused by dog bites. From this evolved the name “canine tooth syndrome.” However, the mechanism of injury is typically with a hook-shaped object. Therefore, it is important to explore medial upper eyelid lacerations, especially when caused by a hook-like structure.
Because there have been so few reports, management modalities are largely anecdotal. Bachynski and Flynn1 described two cases of superior oblique muscle tendon damage. The tendon was sacrificed in one case, with a resultant superior oblique palsy. Dow3 found that anchoring the avulsed tendon segment to the medial orbit resulted in slight hypertropia on down gaze in adduction, but overall, there was a satisfactory field of binocular single vision. Schmidt and Schroer2 described a case of windshield trauma in which the superior oblique muscle was identified at repair. This muscle was disrupted at its origin and therefore repositioned to the medial orbital wall. Initial postoperative review showed no superior oblique muscle function, with restricted depression in adduction and excyclotorsion. Function of the muscle was evident 6 weeks postoperatively, and traumatic Brown’s syndrome was evident at 3 months with hypotropia in primary gaze.
Reported cases of extraocular muscle laceration or rupture without significant globe or adnexal injury are uncommon.5 Although upper eyelid injuries as a result of trauma are relatively common, those involving the superior oblique muscle are exceedingly rare. Muscle function is compromised postoperatively, and patients may have traumatic acquired Brown’s syndrome.2 Careful exploration of full-thickness lacerations of the medial upper eyelid is essential to exclude injury to the superior oblique tendon. Intraoperative reapproximation of the tendon may preserve some function. Continued follow-up is essential to determine the stability of muscle function because variations can occur many months after the initial surgery.1 Additional strabismus surgery may be required later.
- Bachynski BN, Flynn JT. Direct trauma to the superior oblique tendon following penetrating injuries of the upper eyelid. Arch Ophthalmol. 1985;103:1510–1514.
- Schmidt T, Schroer S. Traumatisches Brown-Syndrom nach Obliquus superior-Abriβ. (Brown Syndrome following traumatic disruption of the superior oblique muscle). Fortschr Ophthalmol. 1987;84:476–478.
- Dow DS. Traumatic avulsion of superior oblique tendon and repair. J Pediatr Ophthalmol. 1971;8:35–38.
- Knapp P. Classification and treatment of superior oblique palsy. Am Orthopt J. 1974;24:18–22.
- Ling R, Quinn AG. Traumatic rupture of the medial rectus muscle. J AAPOS. 2001;5:327–328. doi:10.1067/mpa.2001.118217 [CrossRef]