Accessory Extraocular Muscle as a Cause of Restrictive Strabismus.

Restrictive strabismus resulting from the presence of an accessory extraocular muscle has rarely been reported in the literature. Most articles written on this topic are isolated case reports. The purpose of this paper is to describe a series of 7 similar patients presenting with atypical restrictive strabismus associated with enophthalmos in the affected eye, which was found to be caused by an accessory extraocular muscle attached to the posterior globe near the optic nerve. The medical records of 7 patients who shared these clinical characteristics were retrospectively analyzed. Orbital imaging was obtained in the 7 cases, which were compared. Three of the patients were females and four were males. The left eye was affected in all 4 males and the right eye was affected in the 3 females. The 7 patients presented with the following clinical characteristics: enophthalmos, restriction to eye movements in most fields of gaze, and presence of an anomalous orbital structure that was interpreted on magnetic resonance imaging (MRI) to be an accessory extraocular muscle inserting onto the posterior surface of the globe in the affected eye. The fellow eye was normal in all cases. Five of the 7 patients underwent surgical correction with partial improvement in only one patient. The presence of an accessory extraocular muscle should be included in the differential diagnosis of patients with atypical restrictive strabismus. Orbital computed tomography or MRI are essential for correct diagnosis in these cases.

Toxina botulínica versus cirugía en el estrabismo restrictivo / Botulinum toxin versus surgery in treating restrictive strabismus

OBJETIVOS: Evaluar los resultados del tratamiento con toxina botulÝnica en su correcci¾n y compararlos con los obtenidos por la cirugÝa convencional, en casos con similar grado de severidad del estrabismo. MÉTODOS: Se realiz¾ un estudio descriptivo, prospectivo y comparativo, en el periodo de mayo de 2006 a febrero de 2009, en un grupo de 10 casos, tratados con toxina botulÝnica, por inyecci¾n directa del músculo afectado. Los resultados de este tratamiento se compararon con los obtenidos por la cirugÝa en un grupo de 10 casos. RESULTADOS: La edad, el predominio del sexo, el tiempo de evoluci¾n y la severidad clÝnica del estrabismo, son similares en ambos grupos, por lo que son comparables. Los resultados fueron satisfactorios en el 70 por ciento de los casos tratados con toxina y cirugÝa. Los valores promedios de las dioptrÝas prismßticas de ambos ojos, disminuyeron el dÝa 7, 45 y 90. No hubo diferencias significativas, entre los valores promedios de las dioptrÝas prismßticas corregidas por ambos tratamientos, en casos con similar grado de severidad del estrabismo. CONCLUSIËN: El tratamiento con toxina botulÝnica es menos invasivo que la cirugÝa

OBJECTIVE: To evaluate the results of the treatment with botulinum toxin in the correction of restrictive strabismus and compare them with those of the surgery, in cases affected by similar strabismus severity. METHOD: A prospective, descriptive and comparative study was made in 10 patients with strabismus from May, 2006 to February, 2009, which were treated with botulinum toxin directly injected into the affected muscle. These results were then compared to those of the surgery performed in 10 cases. RESULTS: Age, the predominant sex, the time of evolution and the clinical severity of strabismus were comparable in both groups. The botulinum toxin results were satisfactory in 70 percent of cases treated with toxin and surgery. The average values of the prismatic dioptries of both eyes lowered at 7th, 45th and 90th days. The differences among the average values of the corrected prismatic dioptries in both types of treatment were not significant. CONCLUSION: The treatment with the botulinum toxin is less invasive than the surgery