Forrest J. Ellis

Apparent contralateral inferior oblique muscle overaction after unilateral inferior oblique muscle weakening procedures

BACKGROUND Unilateral inferior oblique muscle weakening surgical procedures often lead to the appearance of inferior oblique muscle overaction in the contralateral eye. The purpose of this study was to determine how different types of unilateral inferior oblique muscle procedures affect the apparent function of the inferior oblique muscle in the contralateral eye. METHODS A computer search was performed to locate all patients on the pediatric ophthalmology service at the Wilmer Ophthalmological Institute who underwent a unilateral inferior oblique muscle weakening procedure from 1980 to 1994. Only patients with a diagnosis of primary inferior oblique muscle overaction were included in the study. RESULTS Fourteen patients met the inclusion criteria. One patient had undergone an anterior transposition of the inferior oblique muscle, seven patients had undergone a 10 mm recession of the inferior oblique muscle, and six patients had undergone a myectomy of the inferior oblique muscle. Before the operation,there was no difference in the inferior oblique muscle function of the contralateral eye among the three groups. However, after the operation apparent inferior oblique muscle overaction developed more frequently and to a greater degree in the contralateral eye among patients in the anterior transposition and 10 mm recession groups than among patients in the myectomy group. CONCLUSION Either anterior transposition or 10 mm recession of the inferior oblique muscle may limit elevation in abduction in the eye on which inferior oblique muscle surgery was performed. The limitation of elevation in abduction may create apparent inferior oblique muscle overaction in the contralateral eye.

Possible association of congenital Brown syndrome with congenital cranial dysinnervation disorders

BACKGROUND Congenital cranial dysinnervation disorders (CCDDs) are known to arise from abnormal development of individual and multiple cranial nerve nuclei or abnormalities in cranial nerve axonal transport. We report our findings for several patients with Brown syndrome in association with other known abnormalities characteristic of CCDDs. METHODS The medical records of patients presenting during a 4-year period with congenital Brown syndrome were retrospectively reviewed. Patients with Brown syndrome confirmed by forced ductions were included in the study if the Brown syndrome was associated with either an abnormal development of the superior oblique muscle or superior oblique paresis, ptosis, Duane syndrome, or other known CCDDs. RESULTS A total of 9 patients with Brown syndrome were identified. Of these, 3 also demonstrated a contralateral superior oblique palsy; 2, a contralateral Duane syndrome; 1, an ipsilateral congenital ptosis; and 3, a moderate to severely hypoplastic ipsilateral superior oblique muscle. CONCLUSIONS Some patients with congenital Brown syndrome are associated with and possibly in the spectrum of CCDDs. We propose that Brown syndrome may be due to abnormal development of the trochlear nerve, which results in physical changes in the superior oblique muscle-tendon-trochlea complex. This results in a tendon that is either long and lax, absent, or abnormally inserted (ie, superior oblique paresis) or a tendon that is restricted in its movements through the trochlea (Brown syndrome).

Phakomatous Choristoma (Zimmerman's tumor)

BACKGROUND Phakomatous choristoma is a rare, congenital, ocular adnexal tumor that is presumed to be of lenticular anlage based on light and electron microscopy. METHODS The authors performed immunohistochemistry using standard commercially available antibodies against vimentin, S-100 protein, and several cytokeratins on a phakomatous choristoma that was excised from the right lower eyelid of a 10-week-old white boy. In addition, a battery of antibodies against lens-specific proteins, including alpha, beta, and gamma crystallins, was used. RESULTS The tumor cells showed intense immunoreactivity for all lens-specific proteins tested. The epithelial cells of the phakomatous choristoma stained positively for S-100 protein and vimentin, the intermediate filament normally found in lens epithelial cells. Keratin markers were negative. CONCLUSIONS The results of immunohistochemistry indicate that the cells of phakomatous choristoma synthesize several types of lens-specific proteins. Complementing previous light and electron microscopic studies, these data strongly support Zimmermans conclusion that this pediatric adnexal tumor is a choristoma of lenticular anlage.

Considerations on the etiology of congenital Brown syndrome.

Purpose of review Brown syndrome is an ocular motility disorder characterized by limited volitional and passive elevation of the eye in adduction. Although originally thought due to abnormalities in the trochlea or tendon sheath (limiting the free movement of the tendon through the trochlea), recent evidence suggests that some cases of congenital Brown syndrome may be related to neurodevelopmental abnormalities of the extraocular muscles (congenital cranial dysinnervation disorders, CCDD). Recent findings CCDD is a term encompassing congenital abnormalities of eye movements caused by congenital innervational abnormalities. The abnormal development of cranial nerve nuclei or abnormalities in cranial nerve axonal transport affects the development of the extraocular muscle(s). Currently, congenital fibrosis of the extraocular muscles, Duane syndrome, Moebius syndrome, Horizontal gaze palsy and progressive scoliosis, and synergistic divergence are included as CCDDs. In addition, congenial ptosis, Jaw Wink ptosis, and congenital superior oblique palsy are also included. Recently, it has been suggested that some cases of congenital Brown syndrome and congenital superior oblique paresis are related, and these entities may be part of the CCDDs spectrum. Summary Important findings regarding the cause of congenital Brown syndrome will be reviewed.