Optic nerve size evaluated by magnetic resonance imaging in children with optic nerve hypoplasia, multiple pituitary hormone deficiency, isolated growth hormone deficiency, and idiopathic short stature.
OBJECTIVE
To objectively define criteria for intracranial optic nerve (ON) size in ON hypoplasia (ONH) on magnetic resonance imaging (MRI) scans.


METHODS
Intracranial ON sizes from MRI were compared between 46 children with ONH diagnosed by ophthalmoscopy (group 1, isolated ONH, 8 children; and group 2, ONH associated with abnormalities of the hypothalamic-pituitary axis and septum pellucidum, 38 children) and children with multiple pituitary hormone deficiency (group 3, multiple pituitary hormone deficiency, 14 children), isolated growth hormone deficiency (group 4, isolated growth hormone deficiency, 15 children), and idiopathic short stature (group 5, idiopathic short stature, 10 children). Intracranial ON size was determined by the cross-sectional area, calculated as [pi x (1/2) height x (1/2) width].


RESULTS
Groups 1 and 2 had lower intracranial ON size than did groups 3, 4, and 5 (P < .001). No patients in groups 3 through 5 who had MRI after 12 months of age (when 95% adult size of ONs is attained) had ONs <2.9 mm 2 . Visual acuity correlated significantly with ON size (P < .01).


CONCLUSIONS
Magnetic resonance imaging of the ONs with cross-sectional area <2.9 mm 2 in a short child more than 12 months of age, with or without hypothalamic-pituitary axis abnormalities, confirms the clinical diagnosis of ONH.
Birkebaek
Niels Holtum
NH
Department of Pediatrics, Aarhus University Hospital at Skejby, Denmark.
Patel
Leena
L
Wright
Neville Bryce
NB
Grigg
John Russell
JR
Sinha
Smeeta
S
Hall
Catherine Margaret
CM
Price
David Anthony
DA
Lloyd
Ian Christopher
IC
Clayton
Peter Ellis
PE
D000293:Adolescent; D001827:Body Height; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D005260:Female; D019382:Human Growth Hormone / Q000172:deficiency; D006801:Humans; D007018:Hypopituitarism / Q000473:pathology; D007223:Infant; D008279:Magnetic Resonance Imaging; D008297:Male; D009900:Optic Nerve / Q000002:abnormalities* / Q000473:pathology*; D010907:Pituitary Hormones / Q000172:deficiency; D025962:Septo-Optic Dysplasia / Q000473:pathology*
D010907:Pituitary Hormones; D019382:Human Growth Hormone