Sonographic evaluation of optic nerve diameter in children with raised intracranial pressure.
OBJECTIVE
The optic nerve is part of the central nervous system, and a rise in intracranial pressure (ICP) can directly affect the perioptic nerve space, leading to an increase in nerve diameter. Transorbital sonography is a safe and easy-to-perform method to measure optic nerve diameter for rapid diagnosis of increased ICP.


METHODS
The optic nerve diameter was measured in 3 individual occasions by transorbital sonography in the transverse view, 3 mm posterior to the papilla in both eyes, and the mean was calculated. Two groups were examined: a control group of children with normal ICP and normal ophthalmologic and optic nerve examination results and a case group with increased ICP as determined by an alternative method.


RESULTS
The sample consisted of 156 children, of which 78 (50%) were in the case group and 78 (50%) were in the control group. Eighty-four subjects (53.7%) were male, and 72 (46.1%) were female. The mean +/- SD ages were 6.9 +/- 5.6 years in the case group and 6.8 +/- 5.5 years in the control group. The mean optic nerve diameters were 5.6 +/- 0.6 mm (range, 4.55 +/- 0.7 to 7.6 +/- 0.6 mm) in the case group and 3.3 +/- 0.6 mm (range, 2 +/- 0.6 to 4.35 +/- 0.6 mm) in the control group. The difference in the means was significant at P < .001.


CONCLUSIONS
Optic nerve diameter, measured by transorbital sonography, was significantly greater in pediatric patients with increased ICP compared with a control group. Transorbital sonography can be used to identify pediatric patients with raised ICP.
Malayeri
Ashkan Akhavan
AA
Radiology Department, Tehran Hospital, Children Medical Center, Gharib Street, Keshavarz Boulevard, Tehran, Iran.
Bavarian
Shirin
S
Mehdizadeh
Mehrzad
M
D000293:Adolescent; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D019586:Intracranial Hypertension / Q000503:physiopathology*; D007427:Intracranial Pressure; D008297:Male; D009900:Optic Nerve / Q000000981:diagnostic imaging*; D014463:Ultrasonography