Optic nerve appearance in patients with Down syndrome.

To the Editors: Children with Down syndrome (DS) are commonly seen by pediatric ophthalmologists because signifi cant ocular conditions are associated with the disorder.1 The presence of optic nerve anomalies has been noted in various small case series on children with DS.2,3 We sought to determine the prevalence and character of optic nerve abnormalities among patients with DS in a large pediatric cohort and to ascertain whether patients with DS and optic nerve fi ndings suggestive of an intracranial process (nerve elevation or pallor) had corresponding central nervous system pathology. A retrospective review of the charts of all patients with DS (10-year study period) seen by the ophthalmology service at Boston Children’s Hospital was performed to identify those with optic nerve anomalies. One hundred sixteen patients with DS and optic nerve abnormalities were identifi ed (116 of 806, 14% of patients with DS). The most frequently identifi ed abnormality was a myopic appearance and/or peripapillary atrophy of the optic nerve head. Other anomalies included peripapillary pigmentation, scleral crescent, optic nerve pallor, and non-myopic peripapillary atrophy (Figure 1). Seventeen patients had elevated optic nerve heads (17 of 806, 2%), eight of whom underwent neuroimaging. No imaged patient was found to have pathology compatible with optic nerve swelling. B-scan ultrasonography was performed on fi ve patients, either after neuroimaging or as a primary diagnostic measure. Optic nerve head drusen were found in all of these children. Four patients with DS in the cohort had pale optic nerves. Optic nerve head anomalies were not attributable to an undiagnosed intracranial lesion in any case. Among the optic nerve anomalies identifi ed in our cohort, we focused particularly on those that could be associated with a vision-threatening or life-threatening process: optic nerve head elevation and optic nerve pallor. In previous small case series, optic nerve head elevation was noted in 3% to 5% of patients with DS.2-4 In this investigation, none of those with elevated or pale nerves had undiagnosed life or vision-threatening pathology either clinically or by neuroimaging. This is consistent with prior research on CNS lesions in the DS population because solid intracranial tumors appear to be extremely rare in these patients.5 Based on our fi ndings in this study, we recommend a systematic approach to evaluating children with DS who have elevated-appearing optic nerves. B-scan ultrasonography may be employed as a fi rstline diagnostic modality in these patients. It is inexpensive, non-invasive, and sensitive for optic disc drusen. A positive scan obviates the need for costly and invasive testing because drusen can be monitored ophthalmoscopically and with visual fi eld testing. In the case of a negative scan, further measures should be considered, including neurologic consultation, neuroimaging, and lumbar puncture. Patients who demonstrate nerve pallor of unknown etiology may prompt neuroimaging in addition to neurologic and/or neuroophthalmic consultation.