Brown Syndrome from Local Anesthesia for Inferior Orbital Fat Decompression.

BACKGROUND Vertical diplopia that follows local anesthesia is usually due to inferior rectus muscle fibrosis. Here, we report a rare case of acquired Brown syndrome following local anesthesia. CASE REPORT A 36-year-old woman underwent right inferior orbital fat decompression under local anesthesia. On the first postoperative day, she developed vertical diplopia. She had left hypertropia, which increased on left gaze, with limitation of elevation of the right eye on attempted adduction. Forced duction test of the right eye revealed resistance on elevation in adduction. Magnetic resonance imaging showed signal alteration, thickening, and irregularity involving the right superior oblique tendon and trochlea region. The diagnosis of iatrogenic Brown syndrome was made. Then, a single dose of 10 mg triamcinolone injection was given near the intratrochlear region. On follow-up, complete resolution of diplopia on primary gaze occurred 12 weeks after the incident. CONCLUSIONS The reported case highlights that local anesthesia carries a risk of Brown syndrome. We believe bupivacaine-induced superior oblique hypertrophy is the underlying mechanism. The patient showed excellent outcome after medical management, with no surgical intervention required after 3 months of follow-up.

Inferior oblique overaction/contracture following retrobulbar anesthesia for cataract extraction with a positive Bielschowsky Head Tilt test to the contralateral shoulder. A report of one case.

BACKGROUND AND PURPOSE: This is a report of a patient with diplopia, hypertropia, extorsion and a positive Bielschowsky Head Tilt Test following retrobulbar anesthesia, due to an inferior oblique muscle overaction-contracture. CASE REPORT: Oculomotor and sensorimotor examinations and ocular motility recordings and Bielschowsky Head Tilt Test demonstrated overaction characteristics overpowering the contracture characteristics of the involved inferior oblique muscle. RESULTS: Weakening of the overacting inferior oblique eliminated the vertical and torsional deviations and the forced head tilt difference upon tilting the head to either shoulder. It also normalized ocular motility and resulted in a symptom-free patient. CONCLUSION: Oblique muscle dysfunction with vertical and torsional deviations and a positive Bielschowsky Head Tilt Test can result from retrobulbar anesthesia.

Second cluster of strabismus cases after periocular anesthesia without hyaluronidase.

We describe a second cluster of cases of iatrogenic strabismus that occurred in clinical practices following cataract surgeries that occurred in 2000 when hyaluronidase was once again unavailable for use in periocular anesthetic regimens. Twelve cases of transient or permanent strabismus were referred by 4 anterior segment surgeons who had no previous cases of postcataract strabismus when performing periocular injections with hyaluronidase. The charts of the patients were reviewed retrospectively. Recurrence of an increase in postoperative strabismus when hyaluronidase became unavailable for a second time supports the concept that this enzyme may be more important than previously suspected in preventing damage to the extraocular muscles after periocular anesthetic injections.

Superior oblique overaction from local anesthesia for cataract surgery.

Traumatic superior oblique dysfunction from cataract surgery appears to be rare, with only 3 reported cases of postoperative Brown syndrome and 1 reported case of postoperative superior oblique weakness. We are not aware of any prior reports of superior oblique overaction occurring after cataract surgery. We describe a patient with acquired superior oblique overaction as a cause of vertical strabismus after cataract surgery. Ocular torsion analysis was essential in localizing the malfunction to the superior oblique muscle. The most likely etiology is myotoxicity from inadvertent intramuscular injection of local anesthetic before cataract surgery.

Anesthetic myotoxicity as a cause of restrictive strabismus after scleral buckling surgery.

PURPOSE: To explore the possibility that anesthetic myotoxicity may play a role in restrictive strabismus following scleral buckling procedures. METHODS: The authors performed a retrospective study of patients who presented with strabismus following scleral buckling procedures. Details were sought regarding the scleral buckling procedure, including type and route of anesthesia. The types of strabismus were compiled, as were relevant findings at strabismus surgery. The contributing vitreoretinal surgeons were surveyed regarding the usual type and route of anesthesia used for their scleral buckling procedures. RESULTS: Over 90% of scleral buckling procedures resulting in significant strabismus were performed under local anesthesia. Of the 17 patients on whom strabismus surgery was performed, 14 had positive forced ductions. A hypodeviation of the buckled eye was the most common presentation. CONCLUSION: Based on the types, patterns, and amounts of strabismus encountered after scleral buckling procedures, and the similarity of these findings to cases of strabismus following retrobulbar anesthesia for cataract procedures, the authors propose that local anesthetic myotoxicity is often the primary cause of strabismus occurring after scleral buckling procedures for retinal detachment.

Restrictive strabismus after retrobulbar anesthesia.

Two rare cases of strabismus resulting from contracture of the extraocular rectus muscles after retrobulbar anesthesia for cataract surgery are described. Clinical signs in both cases suggested that the development of the impaired function of the lateral and superior rectus muscles followed the same pattern: initial stimulation followed by paretic and restrictive stages. Abnormal enlargement of the muscles was identified by computed tomography (CT) and magnetic resonance imaging (MRI). The data indicate that the strabismus was the result of direct injection of anesthetics into the rectus muscle.

Postanesthetic hypotropia: a unique syndrome in left eyes.

PURPOSE: To investigate a recurring syndrome of postoperative hypotropia after cataract surgery performed under local anesthesia. SETTING: Hawaiian Eye Center, Wahiawa, Hawaii, USA. METHODS: Thirty-one left eyes in 2143 cataract surgeries developed postoperative hypotropia. Phacoemulsification and intraocular lens implantation were performed by one surgeon; the anesthetic (containing bupivacaine) was administered by one anesthesiologist who had treated 4200 patients without incident. We conducted epidemiologic, outcomes, and prevention studies to identify the etiology, evaluate hypotropia treatment, and test specific anesthetic techniques, respectively. RESULTS: Changes in preoperative and intraoperative management and surgical methods were unsuccessful in preventing the hypotropia. In 55% of the cases, strabismus surgery was required and in 13%, prism glasses. Early recession of the inferior rectus and conjunctiva was successful. After repeated observations of the anesthetic technique, it was noted that the right-handed anesthesiologist misdirected the retrobulbar needle into the left orbit. This resulted in a change in the anesthetic technique, and there has been no incidence of postoperative hypotropia in 3000 surgeries. CONCLUSION: We believe this syndrome resulted from mytoxicity or perimuscular inflammation, producing contracture hypotropia and restricted elevation of the globe. We propose the term postbupivacaine hypotropia for this chiefly left-sided syndrome.

Inferior oblique muscle injury from local anesthesia for cataract surgery.

BACKGROUND: Vertical rectus muscle injury is commonly cited as a cause of strabismus after cataract surgery. Injury to the inferior oblique muscle or nerve as a complication of cataract surgery has not been described previously. METHODS: Four patients without pre-existing strabismus who had diplopia after cataract surgery were studied. Analysis included prism and cover testing, Lancaster red-green testing, and fundus torsion assessment. RESULTS: Three patients had a delayed-onset hypertropia with fundus extorsion in the eye that underwent surgery, which is consistent with inferior oblique muscle overaction secondary to presumed contracture. The fourth patient had an immediate-onset hypotropia with fundus intorsion in the eye that underwent surgery, which is consistent with inferior oblique muscle paresis. Damage to a vertical rectus muscle or "unmasking" of a pre-existing superior oblique muscle paresis could not explain the history and findings in this group of four patients. CONCLUSION: The inferior oblique muscle contracture observed in three patients may have been caused by local anesthetic myotoxicity, whereas the paresis observed in one patient may have been due to mechanical trauma or anesthetic toxicity directly to the nerve innervating the muscle. Inferior oblique muscle or nerve injury should be considered as another possible cause of postoperative strabismus, especially when significant fundus torsion accompanies a vertical deviation.