retrobulbar fat

retrobulbar fat

[TA]
the mass of fat contained in the orbit that contributes to the support of the eyeball.
References in periodicals archive ?
Enophthalmos of the right globe was present with relative paucity of retrobulbar fat (Fig.
Atrophy of the retrobulbar fat leading to enophthalmos is common, [7,11,12] other potential orbital abnormalities include uveitis and retinal or optic nerve alterations.
Orbital computed tomography and magnetic resonance imaging scans showed an extra-axial, well-defined, 30x30x45-mm mass located in the middle cranial fossa, next to the temporal pole, with its borders indistinguishable from the leptomeningeal and osseous tissues, associated with sphenoidal bone lysis and invading the retrobulbar fat tissue (Figure 2).
Caption: FIGURE 3: Axial contrast enhanced T1WI through the left orbit demonstrating periorbital soft tissue swelling and enhancement (1) and smooth circumferential enhancement of sclera (2) and choroid (3); enhancement of the left optic nerve sheath and retrobulbar fat (4).
TSH receptors can not only be found in the thyroid but also in the extraocular eye muscles and retrobulbar fat tissues.
Graves' ophthalmopathy usually presents as bilateral, symmetrical enlargement of the extraocular muscles associated with increase in retrobulbar fat volume.
The upward rotation of eye in response to sudden stimulus and also the cushioning effect of retrobulbar fat are also protective.
Orbits are ideal for CT imaging because of large differences in attenuation coefficient of globe, muscles, nerve, vessels and retrobulbar fat. Contrast enhancement may add definition and specificity in setting of orbital tumours.
A Recent Review of the CT Features of Orbital Pseudotumours revealed * Contrast enhancement 95% * Infiltration of the retrobulbar fat 76% * Proptosis 71% * Enlargement of extraocular muscles 57% * Thickening of optic nerve/sheath 38% Orbital pseudotumour were seen to occur in one of five anatomic patterns on CT scan.