Congenital fibrosis of the extraocular muscles: magnetic resonance imaging findings and surgical treatment.

PURPOSE: We analyzed findings of orbital and cranial magnetic resonance imaging (MRI) in patients with congenital fibrosis of the extraocular muscles (CFEOM). We described surgery and its outcome. MATERIAL AND METHOD: Nine out of 10 patients with clinical findings of CFEOM underwent orbital and cranial MRI to perform a study of the extraocular muscles and cranial nerves. A multimodality workstation platform developed by the imaging laboratory of our hospital for PC computer allowed us to visualize and measure the cross sections of the extraocular muscles in a coronal section. Surgery was indicated to resolve strabismus. Outcome was considered favorable if the final deviation was < 10 pd in the primary position without head turn. RESULTS: In 8 cases (6 males, 5 unilateral [3 left eye]), MRI revealed atrophy of at least 1 of the extraocular muscles supplied by the third nerve. Five patients had third nerve aplasia or hypoplasia. Clinical findings were compatible with a probable diagnosis of CFEOM in all 10 patients. Four patients underwent ptosis surgery before being diagnosed with CFEOM. Four patients underwent surgery to correct strabismus and, of these, 2 required multiple interventions (1 needed 4 interventions). Outcome was successful in only 2 cases. CONCLUSION: Orbital and cranial MRI provided useful information about extraocular muscles and cranial nerves in CFEOM. Surgery must be performed on an individual basis; the number of reoperations is high. The outcome of surgery was favorable in half of the cases.

Atypical restrictive strabismus secondary to an anomalous orbital structure: differential diagnosis.

Anomalous orbital structures are very rare causes of restrictive strabismus. Of the 3 types described in the literature, one involves accessory muscle fibers that are innervated by the III and/or VI cranial nerves originating in the posterior orbit and inserting on the globe, optic nerve, or extraocular muscles. Although these structures do not cause specific symptoms that enable us to make a diagnosis, we must take them into account in patients with atypical restrictive strabismus. Computed tomography and, particularly, orbital magnetic resonance imaging are essential for correct diagnosis and treatment, as the only other way to diagnose this condition is through casual findings during surgery to correct strabismus. Our patient was a child who were initially diagnosed as Duane syndrome. Magnetic resonance imaging revealed an anomalous unilateral orbital structure that limited all ocular movements except adduction, and possibly contributed to globe retraction. Surgery for strabismus did not resolve the problem: the posterior location of the orbital structure rendered surgery impossible.

Conjunctival cysts as a complication after strabismus surgery.

PURPOSE: To identify possible factors associated with the development of a conjunctival cyst after surgery for strabismus. METHODS: A descriptive, longitudinal, and retrospective study was done including 12 cases from the past 20 years presenting a conjunctival cyst as a complication of strabismus surgery. Variables included age, sex, eye and muscle operated on, surgical technique used, surgeon, type of suture, and type of conjunctival incision. Fisher's exact test and Pearson chi-square test were used for statistical analysis. RESULTS: The incidence of conjunctival cysts was 0.25%. Although ultimately statistically significant differences in the variables studied could not be demonstrated (P > .05), a greater incidence in the development of this complication in young patients who underwent recession (58.3%) as the surgical technique was observed. CONCLUSION: Recession may be a risk factor in the development of a conjunctival cyst caused by the high frequency of dragging Tenon capsule during this surgical technique.

Etiology and treatment of pediatric sixth nerve palsy.

PURPOSE: To describe the causes and treatment of sixth (abducens) nerve palsy in a series of pediatric patients. METHODS: This was a 14-year retrospective study of sixth nerve palsy in children under 14 years of age. Outcomes studied included horizontal deviation, degree of limitation of abduction, and head turn. Patients were treated with botulinum toxin injection at the time of diagnosis; surgery was indicated if treatment with botulinum toxin was unsuccessful. Success was defined as final deviation of orthotropia with no head turn or diplopia. RESULTS: Sixth nerve palsy was diagnosed in 15 patients (10 boys; mean age, 4.1 years) between 1995 and 2008. Involvement was bilateral in 2 cases and unilateral in 13 (7 right eyes). Causes included neoplasm (4 cases), trauma (2), idiopathic (3), congenital (2), viral (2), and inflammatory (1). Neoplastic causes were associated with other neurologic signs. Recovery was spontaneous in 5 cases (2 idiopathic, 1 traumatic, 1 congenital, and 1 inflammatory). Botulinum toxin was successful in 7 of 10 patients treated, with follow-up surgery required in the remaining 3 cases. The final result was good in all cases. In all 15 patients, mean time from diagnosis to resolution was 39 months (range, 5 to 170 months). CONCLUSIONS: Neoplasms were the most frequent cause of sixth nerve palsy in our patient population. Recovery was spontaneous in one third of the patients. Most required treatment with botulinum toxin, which was successful in most cases. Surgery was successful after a single procedure.