The Orbits, Optic Pathways, and Vision Loss

 

Jane L. Weissman, MD, FACR

Professor of Radiology, Ophthalmology, and Otolaryngology

Oregon Health and Science University

www.ohsu.edu/radiology/weissman.html

RSNA 2007

 

Eyelid

                Edema, hematoma

                Tumor:  plexiform neurofibroma           

                Ptosis:  sympathetic, oculomotor (CN3), myasthenia gravis

                Tumors of the conjuctiva::  best assessed clinically

 

Anterior Chamber

                Contains aqueous (Note:  so does posterior chamber)          

                Deep:  ruptured globe or subluxed lens 

                Shallow:  ruptured anterior chamber

                Dense:  hyphema

 

Lens       

     The least hydrated soft tissue in the body

Normal:  dense on CT, hypointense on MR         

                Cataracts, intraocular lens implants, aphakia

 

Vitreous

                Normal appearance on CT, MR            

                Hemorrhage, foreign body

                                DDx:   silicone oil for retinal detachment

                                Terson’s syndrome

                Tumor    

                                choroid melanoma, metastasis               

                                retinoblastoma-      

CT best for calcium, MR for extension into nerve

                                                most frequent ocular neoplasm in children            

                                                20-35% bilateral

                                                75% with retinal detachment

                                                deletion of chromosome 13 protective gene-         

                                                                somatic (retina):  unilateral

                                                                germ cell:  bilateral, autosomal dominant

                                                also pineal and suprasellar tumors

 

                TORCH 

                Retinopathy of prematurity (retrolental fibroplasia)

Persistent hyperplastic primary vitreous

                                leukokoria, may have vitreous hemorrhage, small globe

                                Cloquet's canal- primitive hyaloid artery

 

Retina and Choroid

                Retinal detachment-

                                between retinal pigmented epithelium and sensory

epithelium

                Choroidal detachment-

                                choroid is the largest part of the uvea  

uvea:  choroid, ciliary body, iris

 

Globe                                                                                                                      Jane L. Weissman, MD, FACR

                Endophthalmitis    

                Phthisis

                Microphthalmia     

                Coloboma, morning glory anomaly

                Buphthalmos- congenital large globe, glaucoma, NF1

                Staphyloma- acquired, may accompany myopia

               

Optic Nerve

                Four parts:  intraocular, intraorbital, intracanalicular, intracranial

 

                Disk:  papilledema implies increased intracranial pressure

                                papillitis:  30% of patients with MS and optic

neuritis have papillitis

                                drusen- acellular material, may calcify, "pseudo disk edema"

 

                Intraorbital, intracanalicular, intracranial nerve:     

optic neuritis- inflammation and demyelination

                                patients usually present with acute unilateral loss of

vision especially color vision, severe orbital pain, abnormal pupil reflexes

                                  high signal of nerve on T2 and STIR, enhancement with Gd

                                MS just one cause of optic neuritis

                                                other causes:  lupus, temporal arteritis, syphilis,

                                                                herpes, ischemia, radiation therapy, sarcoid, cat scratch disease

                                Optic nerve sheath meningioma

                most in middle aged women, progressive loss of vision

                                                                and proptosis

                                Leukemia

                                Ischemic optic neuropathy (glaucoma, compression- Graves disease)

                                Optic atrophy- result of ischemia, inflammation, trauma

                                Optic nerve hypoplasia (deMorsier)

                                Optic nerve “glioma”

 

Optic Chiasm

                Center is temporal visual fields             

                Periphery is nasal visual fields

                Intrinsic pathology (e.g., glioma) and extrinsic (e.g., pituitary, aneurysm)

 

Optic Tracts         

                Any retrochiasmatic pathology causes hemianopsia

                Left optic tract handles right visual field, and vice versa

 

Lateral Geniculate Nucleus of Thalamus

                Left LGN pathology causes right hemianopsia, and vice versa

 

Superior Colliculus

                Probably coordinates eye movements

 

 

 

This web site and contents are provided for informational and education purposes only and are not intended as medical advice nor intended to create any physician-patient relationship.  Please remember that this information should not substitute for a visit or a consultation with a health care provider.  The views or opinions expressed in the resources provided do not necessarily reflect those of OHSU or the Radiological Society of North America.  Copyright 2002.  For problems or questions regarding this website contact the Webmaster.  Last updated 1/1/2002.

 

Optic Radiations (Geniculocalcarine Tracts)                                                   Jane L. Weissman, MD, FACR

                Run round trigone of lateral ventricle

                Temporal lobe radiations handle superior visual field

                Parietal lobe radiations handle inferior visual field

                Occipital lobe (calcarine cortex is medial occipital lobe):

                                inferior part handles superior visual field

                                superior part handles inferior visual field

                                bilateral occipital lobe pathology->cortical blindness

 

Extra-ocular Muscles and Their Nerves

                Six muscles in each orbit

                Three nerves (CN3, 4, 6)- all with brainstem nuclei

                                Chronic palsies can be detected on CT, MR (atrophy)

                                                Knowledge of path of each nerve essential for identifying etiology

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 



 

This web site and contents are provided for informational and education purposes only and are not intended as medical advice nor intended to create any physician-patient relationship.  Please remember that this information should not substitute for a visit or a consultation with a health care provider.  The views or opinions expressed in the resources provided do not necessarily reflect those of OHSU or the Radiological Society of North America.  Copyright 2002.  For problems or questions regarding this website contact the Webmaster.  Last updated 1/1/2002.

 

 

Suggested Readings                                                                                             Jane L. Weissman, MD, FACR

Armington WG, Bilaniuk LT, Zimmerman RA.  Visual pathways.  In Som PM, Curtin HD, editors.  Head and Neck Imaging (3rd edition). St. Louis:  Mosby, 1996:1184-1231.

 

Brodsky MC, Beck RW.  The changing role of MR imaging in the evaluation of acute optic neuritis.  Radiol 1994;192:22-23.

 

Birchall D, Goodall KL, Noble JL, Jackson A.  Graves ophthalmopathy:  Intracranial fat prolapse on CT images as an indicator of optic nerve compression.  Radiol 1996;200:123-127.

 

Carlow TJ.   Ophthalmoplegic migraine:  Is it really migraine?  (The Hoyt lecture)  J Clin Neuro-Ophthal 2002;22:215-221.

 

Glatt HJ.  Optic nerve dysfunction in thyroid eye disease:  A clinician’s perspective.  Radiol 1996;200:26-27.

 

Hosten N, Bornfeld MD, Wassmuth R, Lemke A-J, Sander B, Bechrakis NE, Felix R.  Uveal melanoma:  Detection of extraocular growth with MR imaging and ultrasound. Radiol 1997;202:61-67.

 

Jacobson DM.  Symptomatic compression of the optic nerve by the carotid artery:  Clinical profile of 18 patients with 24 affected eyes identified by magnetic resonance imaging.  Ophthalmology 1999;106:1994-2004.

 

Kline LB, Bajandas FJ.  Neuro-Ophthalmology Review Manual (4th edition).  Thorofare, NJ:  SLACK, Inc., 1996

 

Mafee MF.  Eye and orbit.  In Som PM, Curtin HD, editors.  Head and Neck Imaging (3rd edition).  St. Louis:  Mosby, 1996:1009-1128.

 

Mafee MF, Peyman GA.  Choroidal detachment and ocular hypotony:  CT evaluation.  Radiol 1984;153:697-703.

 

Mafee MF, Peyman GA, Grisolano JE, Fletcher ME, Spigos DG, Wehrli FW, Rasouli F, Capek V.  Malignant uveal melanoma and simulating lesions:  MR imaging evaluation.  Radiol 1986;160:773-78.

 

Ortiz O, Schochet SS, Kotzan JM, Kostick D.  Radiologic-pathologic correlation: Meningioma of the optic nerve sheath.  Am J Neuroradiol 1996;17:901-906.

 

Schmalfuss IM, Dean CW, Sistrom C, Tariq Bhatti M.  Optic neuropathy secondary to cat scratch disease:  Distinguishing MR imaging features from other types of optic neuropathies.  AJNR Am J Neuroradiol 2005;26:1310-1316.

 

Walsh TJ, ed.  Visual Fields:  Examination and Interpretation (2nd edition).  San Francisco:  American Academy of Ophthalmology, 1996.

 

Weber AL, editor.  Neuroimaging Clinics of North America:  Imaging of the Globe, Orbit, and Visual Pathway, February 1996.

 

Weissman JL, Beatty RL, Hirsch WL.  Enlarged anterior chamber:  CT finding of a ruptured globe.  Am J Neuroradiol 1995;16:936-938.

 

Yanoff M, Fine B.  Ocular Pathology (4th edition).  London:  Mosby-Wolfe, 1996.

This web site and contents are provided for informational and education purposes only and are not intended as medical advice nor intended to create any physician-patient relationship.  Please remember that this information should not substitute for a visit or a consultation with a health care provider.  The views or opinions expressed in the resources provided do not necessarily reflect those of OHSU or the Radiological Society of North America.  Copyright 2002.  For problems or questions regarding this website contact the Webmaster.  Last updated 1/1/2002.