Abstract
Purpose: :
Down Syndrome patients are commonly in the care of an ophthalmologist given the variety of ocular conditions associated with Down Syndrome. Previous authors noted an increased number of retinal vessels crossing the optic nerve head in patients with Down Syndrome, as well as a number with disc elevation, but the sample sizes in these studies were small. The purpose of this study is to determine the prevalence and character of optic nerve abnormalities among patients with Down Syndrome in a pediatric cohort at a single institution.
Methods: :
A query was performed against the Children’s Hospital Boston patient database between 2000 and 2010 using diagnosis codes for Down Syndrome and codes corresponding to optic nerve abnormalities. All patients were seen in the ophthalmology department. Duplicate and miscoded records were excluded, and the charts of these identified patients were reviewed.
Results: :
Twenty-four of 793 (3%) patients with Down Syndrome seen in the ophthalmology department had clinically-determined optic nerve abnormalities. Thirteen patients (54%) were girls. The most frequently identified abnormality was elevation of the optic nerve head (8/24, 33.3%). Four of these patients were found to have optic nerve head drusen by ultrasound. Other anomalies included tilted/myopic nerves (25%), hypoplastic/small discs (21%), pallid nerves, and optic nerve head colobomas (4%). Twelve percent of the patients had poorly classified optic nerve anomalies. Cycloplegic refraction data were available for all patients. The average spherical equivalent was -1.73D in the right eye and -1.47D in the left eye at the time of diagnosis. Six patients (25%) had a final refraction consistent with high myopia (<-8.00D) in one or both eyes. Subjective acuity testing ranged from fix and follow to 20/25, though various methods of measurement were used. Mean visual acuities at the time of diagnosis were 20/74 in the right eye and 20/76 in the left eye.
Conclusions: :
A small percentage (3%) of patients with Down Syndrome presenting to Childrens Hospital Boston ophthalmology clinic were found to have optic nerve anomalies. A variety of abnormalities were identified in our cohort. Optic nerve elevation was the most prevalent finding among those with documented anomalies, and several of these patients were found to have benign drusen. Pediatric ophthalmologists may be able to counsel families and primary care providers using the findings from this investigation.
Keywords: optic nerve • neuro-ophthalmology: optic nerve • neuro-ophthalmology: diagnosis