Retrobulbar meningiomas may be originated from a secondary extension of an intracranial neoplasm through the optic nerve or as a primary orbital tumor, from the arachnoid cells of the
intraorbital optic nerve sheath (CHOW & MILES, 1991).
Ophthalmic neuroimaging findings in IIH reflect the mechanical deformations of the optic nerve sheath, lamina cribrosa, and posterior sclera due to increased CSF pressure transferred through the
intraorbital optic nerve, and these findings are generally reported based on subjective radiologic interpretations in studies (18,22,23).
The change of intracranial subarachnoid fluid pressure directly reflects on the
intraorbital subarachnoid zone.
c) Distance between infraorbital foramen (Diof): Maximum distance between two
intraorbital foramen.
1), LNs (n=12), sialadenitis (n=3), retroperitoneal fibrosis (n=4), renal lesions (n=1), sclerosing cholangitis (n=3),
intraorbital inflammation (n=1), and a paravertebral mass (n=1).
Orbital compartment syndrome (OCS) is a rare but potentially devastating ophthalmic emergency caused by a rise in
intraorbital pressure (IOP) requiring emergent orbital decompression to preserve vision.[28] Typically, an IOP >20 mmHg is considered elevated, and an increased IOP may compress the optic nerve directly or cause compression of its vasculature.[29]
Tumors of the optic nerve are typically solid without a cystic component, cause the expansion and distortion of the nerve, and may result in the "dotted i" appearance of the
intraorbital optic nerve by causing the buckling of the nerve just proximal to the globe (Figure 1c).
Intralesional injection of gentamicin with the goal of destroying fluidproducing cells may be a safe and effective way to treat
intraorbital cysts in birds and other species, although additional research would be required to confirm this.
Any patient undergoing FESS for nasal polyposis must be informed of the long-term risk of mucocele development that can lead to
intraorbital or intracranial complications, and occasionally difficult revision surgeries.
Ocular and periocular tumors of the horses are categorized according to their anatomical locations which are 1) Orbit, 2) Eyelid, adnexa/palpebral conjunctiva, membrana nictitans, 3) Cornea/sclera/bulbar conjunctiva and 4)
Intraorbital regions (Lavach and Severin, 1977; Montgomery, 2014).
Coronal sections demonstrated its
intraorbital extension (Figure-2b).