TY - JOUR
T1 - Orbital Volumetry in Graves' Orbitopathy
T2 - Muscle and Fat Involvement in relation to Dysthyroid Optic Neuropathy
AU - Al-Bakri, Moug
AU - Rasmussen, Åse Krogh
AU - Thomsen, Carsten
AU - Toft, Peter Bjerre
PY - 2014
Y1 - 2014
N2 - Purpose. We wanted to investigate the relative significance of fat and muscle enlargement in the development of dysthyroid optic neuropathy (DON) in Graves' orbitopathy (GO). Methods. Preoperative coronal CT scans of 13 patients with and without DON who subsequently underwent orbital decompression were retrospectively analyzed. Thirteen patients imaged for unilateral orbital fractures served as controls. Results. The retrobulbar muscle volume was 2.1 ± 0.5 cm(3) (mean ± SD) in controls, 4.3 ± 1.5 cm(3) in GO without DON, and 4.7 ± 1.7 cm(3) in GO with DON. The retrobulbar fat volume was 5.4 ± 1.6 cm(3) in controls, 8.7 ± 8.0 cm(3) in GO without DON, and 9.4 ± 3.1 cm(3) in GO with DON. The muscle and fat volumes were higher in patients with GO than in controls (P < 0.001), but the volumes in orbits with and without DON were not significantly different. The volume of the optic nerve were similar in the 3 groups. The number of apical, coronal 2 mm thick slices with no fat was 2.9 ± 0.9 in normal orbits, it was 4.1 ± 1.0 in GO orbits without DON and 5.3 ± 0.8 in GO orbits with DON (P = 0.007). Conclusion. Apical muscle enlargement may be more important than orbital fat enlargement in the development of DON. However, the fact that apical crowding and muscle enlargement also occur in orbits without DON suggests that other factors also play a role in the development of DON.
AB - Purpose. We wanted to investigate the relative significance of fat and muscle enlargement in the development of dysthyroid optic neuropathy (DON) in Graves' orbitopathy (GO). Methods. Preoperative coronal CT scans of 13 patients with and without DON who subsequently underwent orbital decompression were retrospectively analyzed. Thirteen patients imaged for unilateral orbital fractures served as controls. Results. The retrobulbar muscle volume was 2.1 ± 0.5 cm(3) (mean ± SD) in controls, 4.3 ± 1.5 cm(3) in GO without DON, and 4.7 ± 1.7 cm(3) in GO with DON. The retrobulbar fat volume was 5.4 ± 1.6 cm(3) in controls, 8.7 ± 8.0 cm(3) in GO without DON, and 9.4 ± 3.1 cm(3) in GO with DON. The muscle and fat volumes were higher in patients with GO than in controls (P < 0.001), but the volumes in orbits with and without DON were not significantly different. The volume of the optic nerve were similar in the 3 groups. The number of apical, coronal 2 mm thick slices with no fat was 2.9 ± 0.9 in normal orbits, it was 4.1 ± 1.0 in GO orbits without DON and 5.3 ± 0.8 in GO orbits with DON (P = 0.007). Conclusion. Apical muscle enlargement may be more important than orbital fat enlargement in the development of DON. However, the fact that apical crowding and muscle enlargement also occur in orbits without DON suggests that other factors also play a role in the development of DON.
U2 - 10.1155/2014/435276
DO - 10.1155/2014/435276
M3 - Journal article
C2 - 25101183
SN - 2090-4452
VL - 2014
SP - 1
EP - 6
JO - International Scholarly Research Notices
JF - International Scholarly Research Notices
M1 - 435276
ER -