PT  - JOURNAL ARTICLE
AU  - Chan, L.-L.
AU  - Tan, H.-E.
AU  - Fook-Chong, S.
AU  - Teo, T.-H.
AU  - Lim, L.-H.
AU  - Seah, L.-L.
TI  - Graves Ophthalmopathy: The Bony Orbit in Optic Neuropathy, Its Apical Angular Capacity, and Impact on Prediction of Risk
AID  - 10.3174/ajnr.A1413
DP  - 2009 Mar 01
TA  - American Journal of Neuroradiology
PG  - 597--602
VI  - 30
IP  - 3
4099  - http://www.ajnr.org/content/30/3/597.short
4100  - http://www.ajnr.org/content/30/3/597.full
SO  - Am. J. Neuroradiol.2009 Mar 01; 30
AB  - BACKGROUND AND PURPOSE: Optic neuropathy (ON), a serious complication of Graves ophthalmopathy, is often subclinical and masked by symptoms of orbitopathy. We examined herein bony and soft-tissue CT features associated with ON, including an angular assessment of orbital apex capacity, and their usefulness in the risk prediction of ON.MATERIALS AND METHODS: The CT scans of 41 patients with Graves ophthalmopathy (17 men, 24 women; mean age, 49.1 years) clinically diagnosed with (19 patients, 32 orbits) or without ON were evaluated by 2 independent raters. Quantitative linear and angular measurements of the orbital structures and bony walls and categoric scores of apical crowding and intracranial fat prolapse were assessed on a clinical workstation. Inter- and intrarater variability of these features was determined. The CT features of the 2 patient groups were compared, and multivariate logistic regression analysis was performed to evaluate the predictive features of ON.RESULTS: Bony orbital angles (P < .005), length of the lateral orbital wall (P < .05), muscular diameters (P < .0005), muscular bulk of the medial rectus muscle relative to the bony orbit (P < .05), and apical crowding (P < .0005) were associated with clinical ON. Stepwise multivariate logistic regression analysis revealed the muscle diameter index and medial and lateral wall angles to be independent predictors. Combining these in a single multivariate equation yielded sensitivity, specificity, and positive and negative predictive values of 73%, 90%, 82%, and 85%, respectively.CONCLUSIONS: Orbital wall angles, especially the medial wall, and muscular enlargement are independent risk predictors.