PENN RADIOLOGY THE ROOTS OF RADIOLOGICAL EXCELLENCE This Eye Does Not Look Right. An Imaging Overview of Common Oculoplastic and Orbital Surgeries. eEdE-109

PENN RADIOLOGY

THE ROOTS OF

RADIOLOGICAL

EXCELLENCE

This Eye Does Not Look Right.

An Imaging Overview of Common Oculoplastic and Orbital Surgeries. eEdE-109

Farbod Nasseri

S. Ali Nabavizadeh

Laurie A. Loevner

Arastoo Vossough

Suyash Mohan

Neuroradiology DivisionDepartment of Radiology University of Pennsylvania

Baltimore, Maryland

Perelman School of Medicine at University of Pennsylvania Penn Radiology

Disclosure statement

• Neither the authors nor their immediate family members have a

financial relationship with a commercial organization that may

have a direct or indirect interest in the content.

Baltimore, Maryland


Purpose

• To present a comprehensive and systematic review of the

imaging spectrum of the oculoplastic and orbital surgeries

including various types of orbital implants and prostheses.

• To review imaging features of potential surgical complications

and discuss plausible pitfalls.

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Approach

• Orbital surgeries

Reconstruction, augmentation, decompression

Enucleation, evisceration, exenteration

• Lacrimal apparatus surgery

• Lens surgery & implants

• Eyelid surgery

• Strabismus surgery

• Glaucoma surgery

• Retinopexy & scleral buckles

• Intraocular injection

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Discussion

• The development of new surgical techniques, as well as advances in the

prostheses offer a wide range of novel alternatives for orbital and

oculoplastic surgeries.

• Imaging plays a critical role in the postoperative setting, enabling early

diagnosis of complications as well as long term follow-up evaluation.

• A comprehensive pictorial review of postoperative orbit will be presented.

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Orbital wall reconstruction/augmentation

Imaging: To assess for complications: • Foreign body reaction (allograft implant)• Infection • Extrusion, deformity, subsiding• Rectus muscles impingement, optic nerve compression• Lacrimal sac obstruction

Implant material

Traditional

Titanium

Silicone

Autologous cartilage or bone

New Porous polyethylene

Pros Cons

Porous polyethylene

Titanium

Allow vascularizationImproved biocompatibilityNo need for fixation

Infection

Accurate contour Large defect

CostNeeds fixation

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6 Y/F with fibrous dysplasia & left optic nerve compression symptoms treated with frontal orbital advancement &

reconstruction of the left orbital roof

CoronalCT

CoronalT1 MR

Coronal CT

3-D volume rendered CT

Extensive involvement of left calvarium with fibrous dysplasia causing narrowing of left orbital apex & left eye proptosis.

*

*

Postop

Orbital decompression and orbital roof reconstruction using bone grafts.

3-month follow-up

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53 Y/M with facial & orbital floor (blow-in) fractures after falling off skateboard

Pre opCoronal CT

Multiple facial bone fractures including the inferior wall of the left orbit. Small displaced bone fragment in left orbit.

Post opCoronal CT

Reconstruction of the inferior wall of the left orbit with a metallic mesh.

Fixation of left lateral orbit & inferior orbital rim using screws/plates.

Post op3-D volume rendered CT

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53 Y/M with sinonasal undifferentiated carcinoma (SNUC) of right maxilla & orbit, status post right maxillectomy & exenteration followed by left radial

forearm free flap reconstruction 2 years later

Heterogeneously mass within the right maxillary sinus with extension into the right nasal cavity & into right orbital floor, abutting the right inferior rectus muscle

Orbital exenteration, maxillectomy reconstruction using metallic mesh, sphenoidotomy & ethmoidectomy. Radial forearm free flap reconstruction

3-D volume rendered CT

Post opCoronal T1

Axial T1

Pre

op

Pos

t op

Coronal T1

Coronal T1 Axial T1

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Orbital Decompression • Indication: Thyroid-related immune orbitopathy (TRIO)

Improve

Proptosis and intraocular pressure.

Visual acuity

• Techniques: resection of the medial, lateral, or inferior orbital walls

• Imaging:

• Bulging enlarged orbital fat and rectus muscles through these defects.

• Resection of portion of paranasal sinuses.

• Complications: globe displacement diplopia, CSF leak, optic neuropathy,

orbital cellulitis, excess herniation of orbital contents sinus obstruction.

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71 Y/F with thyrotoxic exophthalmos & compressive optic neuropathy

Bilateral orbital decompression with defects of the medial orbital walls. Continued enlargement of the extraocular muscles.

Enlargement of bilateral extraocular muscles.

Decreased crowding at the orbital apices (left more than right) with mild medial deviation left optic nerve.

Coronal CT

CoronalT1

CoronalT1

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Orbital Enucleation / EviscerationEvisceration: removal of globe contents, preserving the sclera & extraocular muscles.

Enucleation: removal of globe contents entirely, preserving the extraocular muscles.

Indication

Intraocular malignancies

Irreparable globe rupture

Prevention of sympathetic ophthalmia

Materials: metallic (old), hydroxyapatite, solid silicone, & Medpor (new).

Pitfall: Diffuse linear enhancement surrounding the implant (no clinical significance).

Complications: rotation, infection, inflammation, & exposure.

Implant Components

Cover shell / eye prosthesis (anterior)

Orbital implant (posterior)

Globe implants: provide orbital volume for cosmesis following enucleation.

www.oasa.org.za

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76 Y/F with history of right supraorbital/ frontal scalp squamous cell carcinoma status post Mohs surgery

T2 & enhanced T1 images show right supraorbital & frontal scalp tumor with perineural spread along supraorbital nerve.

Postop: right eye evisceration.

CoronalT1 post

CoronalT2

Axial CT

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Orbital Exenteration

• Complications: fistulae, necrosis, dehiscence, infection.

Indication Primary orbital malignancies

Orbital invasion by periorbital malignancies

Exenteration types

Subtotal: sparing of the eyelid

Total (extended): removal of eyelid + orbit

Radical: removal orbit + periorbial structures

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56 Y/F with right sinonasal melanoma treated with orbital exenteration

Orbital exenteration & myocutaneous free flap reconstruction extending into the right maxillary sinus, nasal cavities & ethmoid air cells.

Melanoma filling the nasal cavity, ethmoid air cells, extending into the maxillary, frontal, and sphenoid sinuses, with intraorbital extension to the medial extraconal fat, and the trochlea, medial rectus, and inferior muscle complex, involving the planum sphenoidale, and mild dural extension. Complicated with bilateral subdural effusions.

***

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25/M with gunshot wound, extensive post-traumatic changes presented with an orbital mass.

Left globe prosthesis. Patient developed extra-osseous mucocele postoperatively in the region of the left superior orbital rim. Notice: Right globe is absent.

Extra-osseous enlarging mucocele on 3-month follow-up. Left globe prosthesis.

*

Axial CT Axial CT

*

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Lacrimal apparatus surgery

Dacryocystorhinostomy (Preferred treatment)• Remove bone from medial canthus connect nasolacrimal duct with nasal cavity.

• External • Endonasal

• Complications: Restenosis

Relieve lacrimal obstruction

Dacryocystorhinostomy

Nasolacrimal duct stents or Jones tubes

Nasolacrimal duct stents / Jones tubes:

• Composed of metalor plastic. Tubular structure + “mushroom” component

• Complications: stent malposition or migration, inflammation, pneumorbit

• Poor long-term patency

• Up to 65 % of stents become occluded by granulation tissue or mucoid debris

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60 Y/M with right lacrimal sac carcinoma s/p right maxillectomy with reconstruction, presents with epiphora

Right dacryocystorhinostomy with stent placement, extending into the nasal cavity

Sequential Coronal CT Coronal T2 MR

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Lens surgery and implants

• Imaging: Lens prostheses are very thin structures in profile.

• Optic: radiodense on CT , low signal intensity on both T1 & T2 MRI.

• Haptic: may not visible at 1.5 T MRI or on thin-section CT.

• Intraocular lens prostheses do not normally enhance.

• Complications: retained lens fragments, displacement, dislocation, calcifications.Intraocular

lens implants Optic (clear lens)

Haptics (stabilizing arms)

• Cataracts are common causes of vision loss

Intraocular lens implant: Replacement after lens extraction

Optic

Hapticswww.nature.com/eye/journal

Lensectomy:

• Resection of the crystalline lens (transscleral retrociliary incision).

• Mainly for treatment of pediatric cataracts.

• Imaging: no apparent separation between the anterior chamber and the globe.

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Intraocular lens implant

Dystrophic calcification on the surface of the right intraocular lens implant.

Right prosthetic lens implant: optic and haptics. Native left lens.

Axial T1

Axial T1

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Eyelid surgeryEyelid Weights

• Indication: Facial nerve deficits lagophthalmos keratitis

• Implanted subcutaneously in the upper eyelid

• Secured to the tarsus enabling eye closure

• Gold eyelid weights: MRI compatible

• >90 % improved visual acuity

• Complications:

• Infection, allergic reaction, migration, & extrusion

The patient has a history of left facial nerve palsy. A left upper eyelid weight which causes streak artifacts on CT & susceptibility artifact on MRI.

Coronal CT

Axial CT

Axial T2

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Eyelid surgeryBlepharoplasty

• Surgical reconstruction of the eyelids.

• Indications: ptosis, thyroid orbitopathy, and facial cosmesis.

Blepharoplasty techniques

Sling blepharoplasty: suspend the eyelid to the frontal bone.

Augmentation blepharoplasty: using implants or tissue repositioning.

Reduction blepharoplasty: removal of excess tissue.

• Imaging:

• Often no appreciable imaging correlate

• Some materials used for augmentation can be seen

• Sling blepharoplasty anchors

• Complications:

• eyelid malposition, strabismus, scarring, & persistent edema

Baltimore, Maryland


Strabismus surgery

• Repositioning portions of the rectus muscle bellies onto the sclera

Imaging

Changes in size and morphology of the rectus muscles

Improved ocular alignment

Evaluating postoperative complication

• Complications: rectus muscle rupture/slippage, infection

Indications

Diplopia (nerve palsy)

Reduced binocularity

Constricted visual field secondary to strabismus

Abnormal head position secondary to ocular misalignment

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6 m/F with Axenfeld Rieger syndrome presented with congenital hypoplastic lateral rectus muscles

The globes are rotated internally. The lateral rectus muscles are hypoplastic.

Pre

op

Pos

t op

Status post right strabismus surgery, involving transposition of superior and inferior rectus laterally. Resolution of internal rotation of the globes. New right hypertropia and dissociated vertical deviation due to unbalanced transposition (slight overcorrection).

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Glaucoma surgery

• Bleb (Reservoir): A fibrous capsule forms around the aqueous humor

• Glaucoma valve implants are MRI compatible

• Low signal on both T1- and T2-WI surrounded by a small amount of fluid in the reservoir

• Complications: malposition, obstruction, giant bleb formation, infection, choroidal detachment

Types of shunt implants

Non-valved: Molteno, Baerveldt.

Valved: Ahmed, Krupin.

www. sanantonioeyeinstitute.com

Valve shunt Valve

Plate: implanted underneath the conjunctiva

Tube: inserted into the anterior chamber

• Purpose: to reduce intraocular pressure by decompression of aqueous humor

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Left Ahmed shunt valve supralateral to the left optic globe shows linear low signal on T1 and T2 images & linear hyperdensity on CT which is surrounded by fluid (blebs).

2 Y/F with Sturge-Weber syndrome

and a glaucoma shunt

www. sanantonioeyeinstitute.com/glaucoma-tube-shunts/

Coronal T2 Sagittal CT

Sagittal T1

http://sanantonioeyeinstitute.com/

http://sanantonioeyeinstitute.com/

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2 Y/F with Sturge-Weber syndrome and bilateral glaucoma s/p bilateral Ahmed valved shunts

Coronal & axial T2 images show bilateral linear low signal Ahmed valved shunts surrounded by fluid blebs. Larger amount fluid on the left which indents the globe.

Coronal T2

Coronal T2

Axial T2

Out-pouching of fluid signal within the left orbit, anterior to the valve.

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Retinopexy & scleral buckles

• Scleral buckles or bands: circular devices positioned around the globe for

treatment of retinal detachment. The buckles exert pressure to appose the layers

of the retina together.

• Complications: infection, scleral invasion & extrusion

• Hydrogel implants: less stiff (less scleral erosion), can swell (permeable to water).

CompositionHydrophilic hydrogel polymers (fluid density)

Silicone Solid rubber bands (high density)

Sponges (air density)

http://www.webmd.com/scleral-buckling-surgery-postoperative

Pitfall: mimic orbital mass or infection.

Surgical history, tubular configuration of the implant encircling the globe & lack of restricted diffusion helps in differentiating from infection.

http://www.webmd.com/

http://www.webmd.com/

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85 Y/F with history of retinal detachment, s/p scleral buckle retinopexy

High-density scleral buckles surrounding the right globe.

Pitfall: Scleral buckles may mimic senile calcifications, hemorrhage, or masses.

http://vissioneyes.com/retinal-detachment-treatment.html

Axial CT

Senile calcifications

Axial CT

http://vissioneyes.com/

http://vissioneyes.com/

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48 Y/M with retinal detachement s/p rubber band silicon retinopexy

The scleral band are low signal intensity on T1 & T2 MR.

Axial T2

Axial T1

Coronal T2

Mild indentation on the globe is an expected finding & should not considered abnormal.

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Intraocular injectionsIndication: To tamponade the retina following retinal detachment until chorioretinal adhesions form.

Pneumatic Retinopexy (Intraocular gas injection): (Effective up to 80 %)• To restore intraocular volume during scleral banding• A variety of gases: air, hexafluoride, & perfluoropropane • Imaging: Air lucency is present antidependently in the vitreous body, creating an air-fluid

level• Complications: secondary glaucoma, gas migration, vitreous hemorrhage, endophthalmitis &

proliferative vitreoretinopathy

Intraocular Silicone Injection: • The silicone oil used for tamponade is usually removed after 8 weeks, but may remain

permanently, depending on the risk of recurrent detachment• Imaging: On CT, silicone oil is hyperdense & globular, measuring up to 120 HU • Complications: choroidal detachment, scarring, cataracts, & optic nerve atrophy

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58 Y/M with history of retinal detachment following pneumatic retinopexy

Intraocular air is seen as non dependent hypointensity on T1 & T2 images within the vitreous.

It creates an air-fluid level left orbit.

Axial T1

Axial T2

Sagittal T2

Pitfall: Pneumatic retinopexy can mimic orbital abscess & post traumatic orbital emphysema.

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36 Y/M with traumatic brain injury & retinal detachment.

Intraocular silicone injection for retinopexy.

Axial T2

Axial T1

Axial CT

The intraocular silicone is isointense to muscle & hyperintense to fluid on T1 while hypointense on T2.

Bilateral globular hyperdense silicon in the globes

Pitfall: Silicon can mimic blood, but blood typically layers dependently & is not as dense as the silicone.

Chemical shift artifact, at the interface between the silicone and the vitreous, can distinguish the silicon from blood.

Fat saturation pulses can also help distinguishing the two by causing some degree of signal suppression.

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Conclusion

Familiarity with imaging findings of the wide-ranging spectrum of

postoperative changes are crucial to differentiate expected

postoperative findings from complications.

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Thank you for reviewing our exhibit

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alloplastic implants used in orbital fracture repair. Ophthalmology 99(10):1600–1608

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(Graves’disease). Curr Opin Otolaryngol Head Neck Surg18(1):37–43

3. Christmas NJ, Gordon CD, Murray TG, Tse D, Johnson T, Garonzik S, O’Brien JM (1998) Intraorbital

implants after enucleation and their complications: a 10-year review. Arch Ophthalmol 116(9):1199–

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4. Tyers AG (2006) Orbital exenteration for invasive skin tumours. Eye (Lond) 20(10):1165–1170

5. Nishida Y, Inatomi A, Aoki Y, Hayashi O, Iwami T, Oda S, Nakamura J, Kani K (2003) A muscle

transposition procedure for abducens palsy, in which the halves of the vertical rectus muscle bellies

are sutured onto the sclera. Jpn J Ophthalmol 47(3):281–286

6. Freedman J (2010) What is new after 40 years of glaucoma implants. J Glaucoma 19(8):504–508

7. Chan CK, Lin SG, Nuthi AS, Salib DM (2008) Pneumatic retinopexy for the repair of retinal

detachments: a comprehensive review (1986–2007). Surv Ophthalmol 53(5):443–8

8. Mathews VP, Elster AD, Barker PB, Buff BL, Haller JA, Greven CM (1994) Intraocular silicone oil: in

vitro and in vivo MR and CT characteristics. AJNR 15:343–347

9. Kartush JM, Linstrom CJ, McCann PM, Graham MD (1990) Early gold weight eyelid implantation for

facial paralysis. Otolaryngol Head Neck Surg 103(6):1016–1023

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PENN RADIOLOGY THE ROOTS OF RADIOLOGICAL EXCELLENCE This Eye Does Not Look Right. An Imaging Overview of Common Oculoplastic and Orbital Surgeries. eEdE-109