J Neurol Surg B Skull Base 2020; 81(04): 422-434
DOI: 10.1055/s-0040-1713849
Surgical Approaches to the Orbit
Review Article

Transconjunctival and Transcaruncular Approaches to the Orbit

Natalie Wolkow
1  Department of Ophthalmology, Ophthalmic Plastic Surgery Service, Massachusetts Eye and Ear, Harvard Medical School, Boston, Massachusetts, United States
,
Suzanne K. Freitag
1  Department of Ophthalmology, Ophthalmic Plastic Surgery Service, Massachusetts Eye and Ear, Harvard Medical School, Boston, Massachusetts, United States
› Author Affiliations
 

Abstract

Transcaruncular and transconjunctival approaches are commonly used by ophthalmic plastic surgeons to access various orbital compartments. These approaches are versatile and may be combined with transnasal or transcranial approaches to the orbit to gain optimal access to challenging locations. A major advantage of the transcaruncular and transconjunctival approaches is the lack of a visible skin incision with excellent postoperative cosmesis. As with all orbital surgery, an in-depth knowledge of orbital anatomy and physiology, as well as meticulous hemostasis, is needed to prevent complications including globe injury, permanent vision loss, diplopia, and retrobulbar hemorrhage. This article reviews the surgical steps of these approaches. The indications for each approach and case examples are illustrated.


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Introduction

Transcaruncular and transconjunctival incisions are used routinely by ophthalmic plastic surgeons to gain access to various anatomic compartments within in the orbit.[1] [2] [3] These approaches may be combined with one another or with transnasal or transcranial approaches to the orbit in collaboration with sinus surgeons and neurosurgeons.[1] [4] [5] The indications and basic steps of each approach are reviewed. Surgical complications are discussed, and case studies are illustrated.

Pearls and Tips
  • Excellent knowledge of orbital anatomy is essential.

  • Meticulous hemostasis and care when working around the globe are critical.

  • Detailed assessment of pre- and postoperative visual acuity, pupillary reaction, color vision, extraocular motility, and visual field testing is requisite.

  • Surgeons operating in or around the orbit should be prepared to manage retrobulbar hemorrhages.

  • Transcaruncular incisions allow access to the medial orbital wall, medial extraconal orbit, and medial intraconal orbit.

  • Transconjunctival incisions in the inferior fornix provide access to the orbital floor, inferior extraconal orbit, and inferior intraconal orbit

  • Bulbar transconjunctival incisions allow access to the intraconal orbital space.


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Transcaruncular Approach to the Orbit

Indications

A transcaruncular approach allows access to the medial orbital wall, orbital apex, and medial orbit.[6] This approach can be used for medial orbital fracture repair, medial orbital wall decompression in thyroid eye disease, for removal of medial intraconal and extraconal orbital tumors and for access to bleeding anterior and posterior ethmoid arteries ([Table 1]).Contraindications to the use of a transcaruncular approach include bleeding disorders or the use of blood thinners that increase the risk of retrobulbar hemorrhage, or a history of ocular cicatricial pemphigoid that may worsen with a transconjunctival incision. Advantages of transcaruncular incisions include the ability to avoid cutaneous incisions in the medial canthus or the nasal sidewall skin where cosmetically unappealing webs may form, and the rapid and direct access that such incisions provide to the medial orbit without the need for drills or bone removal.

Table 1

Indications for different surgical approaches to the orbit

Transcaruncular

 Repair of medial orbital wall fracture

 Decompression of medial orbital wall in thyroid eye disease

 Access to bleeding anterior and posterior ethmoid arteries

 Access to medial intraconal or extraconal orbital mass

Transconjunctival, inferior fornix

 Inferior orbital wall fracture

 Lower eyelid blepharoplasty

 Access to inferior orbital intraconal or extraconal mass

 Decompression of inferior orbital wall in thyroid eye disease

Transconjunctival, bulbar conjunctiva

 Repair of open globe injury

 Globe enucleation or evisceration

 Access to intraconal mass in any quadrant

 Optic nerve sheath fenestration in idiopathic intracranial hypertension

 Access to subconjunctival mass

 Strabismus surgery


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Anatomy and Landmarks

The caruncle is a fleshy piece of tissue located in the medial-most aspect of the palpebral fissure ([Fig. 1]).[7] Like the conjunctiva, it has a moist, nonkeratinized surface with goblet cells, but unlike the conjunctiva it has within its substance hair follicles, sebaceous glands, and adipose tissue.[8] Lateral to the caruncle is a fold of conjunctiva, call the plica semilunaris. Superior and inferior to the caruncle are the margins of the eyelid within which run the upper and lower canaliculi of the nasolacrimal system. Posteromedial to the caruncle is the nasolacrimal sac. Important landmarks in the medial orbit behind the caruncle include the posterior lacrimal crest, as well as the anterior and posterior ethmoidal arteries ([Fig. 2]).

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Fig. 1 Anatomy of the caruncle and surrounding structures. The caruncle is a nonkeratinized fleshy piece of tissue in the medial-most aspect of the palpebral fissure. Lateral to the caruncle is a fold of conjunctiva called the plica semilunaris. Superior and inferior to the caruncle within the eyelid margin are the canaliculi of the nasolacrimal system.
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Fig. 2 Anatomy posteromedial to the caruncle. Axial CT imaging of a normal right orbit. The lacrimal sac is highlighted in yellow. The posterior lacrimal crest is indicated in blue. The approximate locations of the anterior and posterior ethmoid arteries are indicated in red. CT, computed tomography.

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Steps to the Approach

  • General anesthesia is induced.

  • A small quantity of local anesthetic (∼0.5 mL) consisting of 2% lidocaine with 1:100,000 epinephrine mixed 1:1 with 0.75% bupivacaine is infiltrated into the caruncle with a 30-G, 0.5-inch needle ([Fig. 3]).

  • A scleral shell is placed to protect the cornea ([Fig. 4]).

  • A vertical incision is made through the lateral one-third of the caruncle or immediately posterior to caruncle with Westcott scissors ([Fig. 5]).

  • Stevens' scissors are used to bluntly palpate and then dissect in an avascular plane to the posterior lacrimal crest ([Fig. 6]).

  • Behind the posterior lacrimal crest, the periorbita (periosteum) is incised with the Freer elevator or Bovie cautery with a Colorado tip

  • The periosteum is elevated in the posterior, superior, and inferior directions.

    • ▪ At this point, a medial orbital wall fracture can be visualized and repaired or a medial orbital decompression can be performed without violating the periorbita. Likewise, the anterior or posterior ethmoidal arteries can be cauterized if bleeding.

    • ▪ At this point, the periorbita can be incised to access lesions such as tumors in the medial extraconal and intraconal compartments.

  • Once the task at hand has been completed, hemostasis is ensured.

  • One or two 6–0 plain gut or 7–0 polyglactin interrupted sutures are placed to close the incision; alternatively, in some cases the caruncular incision can be left to granulate without sutures ([Fig. 7]).

  • The scleral shell is removed and the eye inspected to ensure that there have been no globe injuries.

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Fig. 3 Local anesthetic is infiltrated into the caruncle with a ½ inch 30-gauge needle on a 3-cc syringe. (Image courtesy: Kevin Ma, MD)
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Fig. 4 A scleral shell is inserted to protect the ocular surface from injury during surgery. (Image courtesy: Kevin Ma, MD)
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Fig. 5 The transcaruncular incision is made through the posterior one-third of the caruncle, or immediately posterior to the caruncle with Westcott scissors. (Image courtesy: Kevin Ma, MD)
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Fig. 6 Blunt dissection is continued through an avascular plane with Stevens’ scissors to the posterior lacrimal crest. (Image courtesy: Kevin Ma, MD)
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Fig. 7 At the conclusion of the procedure the globe is inspected to ensure that there have been no injuries. The transcaruncular incision is often well-approximated (as in this case), and can be left to self-seal without sutures or closed with one or two interrupted dissolvable sutures. (Image courtesy: Kevin Ma, MD)

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Advantages of this Approach

Quick, bloodless, small incision that is well-camouflaged and without a skin incision; can be combined with other incisions; no reconstruction necessary, neither bone flaps nor screws or drills.


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Limitations of this Approach

Small, confined space with limited visibility. Use of a headlight by the primary surgeon is highly recommended for the best visibility. If access to the posterior orbit is needed, it may be difficult via this approach; combining a transcaruncular approach with an endoscopic transnasal approach may be useful for very posterior masses or for very posterior orbital decompressions.


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Complications

Potential complications that must be discussed with patients preoperatively include vision loss,[9] retrobulbar hemorrhage, bleeding of the anterior or posterior ethmoidal arteries, cerebrospinal fluid leak, injury to the nasolacrimal system, injury to the medial rectus, inferior oblique or superior oblique muscles, diplopia, ocular surface scarring, and formation of pyogenic granulomas on the ocular surface ([Table 2]).

Table 2

Complications of orbital surgery

Transcaruncular

 Vision loss

 Retrobulbar hemorrhage

 Bleeding of anterior or posterior ethmoid arteries

 Cerebrospinal fluid leak

 Injury to the nasolacrimal system

 Injury to the medial rectus muscle, inferior oblique, or superior oblique

 Diplopia

 Ocular surface scarring or pyogenic granuloma

Transconjunctival, inferior fornix

 Vision loss

 Retrobulbar hemorrhage

 Injury to the infraorbital nerve with hypoesthesia

 Injury to the inferior rectus or inferior oblique muscles

 Diplopia

 Entropion, retraction, or other eyelid malposition

 Inferior forniceal scarring

 Pyogenic granuloma

Transconjunctival, bulbar conjunctiva

 Vision loss

 Retrobulbar hemorrhage

 Injury to any of the rectus muscles

 Diplopia

 Globe perforation (if reattaching muscles)

 Permanently fixed pupil due to ciliary ganglion injury

 Symblepharon and restriction of extraocular motility

 Conjunctival scarring

 Pyogenic granuloma


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Transconjunctival Approach to the Orbit through the Inferior Fornix

Indications

The transconjunctival approach through the inferior fornix can be used to gain access to the orbital floor or the extra- or intraconal inferior orbit.[10] [11] By extending the incision and combining it with a transcaruncular approach, the entirety of the inferior and medial orbit can be exposed. By combining the incision with a lateral canthotomy incision, access can be gained to the inferior and lateral aspects of the orbit. The transconjunctival approach through the lower eyelid is often used for orbital floor fracture repairs. It can also be used for orbital decompressions, for access to inferior, inferomedial, and inferolateral orbital masses, and for transconjunctival cosmetic lower eyelid blepharoplasties.


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Anatomy and Landmarks

An in-depth understanding of lower eyelid anatomy is necessary for the transconjunctival approach through the inferior fornix.[7] [8] The horizontal length of the lower eyelid is approximately 30 mm. The medial aspect of the eyelid houses the punctum and canaliculus, which are part of the lacrimal system. Lateral to the punctum the eyelid is stiffer and composed of two layers, an anterior lamella and a posterior lamella. The anterior lamella consists of the skin and orbicularis muscle. The posterior lamella consists of the tarsal plate and the conjunctiva. The tarsus of the lower eyelid is approximately 3- to 5-mm tall and 25 mm in horizontal length. It is a fibrous structure that contains within it the meibomian glands. The lower eyelid retractors and the orbital septum insert into the inferior edge of the tarsus ([Fig. 8]). The conjunctiva is tightly adherent to the tarsus, but inferior to the tarsus the conjunctiva is looser.

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Fig. 8 Sagittal cross-sectional anatomy of the eyelids and globe. The conjunctiva covers the surface of the globe, the fornices and the internal aspect of the eyelids. (Reprinted with permission from Freitag SK et al.[1])

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Steps to the Approach

  • General anesthesia is induced.

  • A small quantity of local anesthetic consisting of 2% lidocaine with 1:100,000 epinephrine mixed 1:1 with 0.75% bupivacaine is infiltrated into the inferior fornix of the lower eyelid.

  • A scleral shell is placed to protect the cornea.

  • A 4–0 silk traction suture is passed through the posterior lamella of the lower eyelid margin.

  • The eyelid is everted to expose the conjunctival surface, while maintaining tension on the skin to prevent accidental buttonholing.

  • A transconjunctival incision through the conjunctiva and eyelid retractors is made 3 to 4 mm below the inferior border of the tarsus with Westcott scissors or Bovie cautery with a Colorado's tip along the length of the eyelid ([Figs. 9] and [10]).

  • Dissection is continued onto the anterior face of the orbital septum ([Fig. 11]).

    • ▪ At this point, if a lower eyelid blepharoplasty is to be performed, the septum is opened and excess orbital fat is excised ([Fig. 12]).

    • ▪ At this point, if an orbital floor fracture is to be repaired or a decompression is to be performed, the septum that is holding back orbital fat is maintained intact, and instead the periosteum along the inferior orbital rim is incised and elevated to gain access to the orbital floor bones ([Fig. 13]).

    • ▪ At this point, if an orbital mass is to be removed, the periosteum is incised and elevated, dissection is performed posteriorly, and then the posterior periosteum incised to access the extraconal space.

  • Once the task at hand has been completed hemostasis is ensured.

  • If well approximated, the conjunctival incision can be left without sutures; alternatively, one or two 6–0 plain gut interrupted sutures can be placed to close the incision.

  • The scleral shell is removed and the eye inspected to ensure that there have been no globe injuries.

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Fig. 9 Transconjunctival approach to the orbital floor. A transconjunctival incision is typically initiated 3–4 mm below the inferior border of the tarsus through the conjunctiva and lower eyelid retractors. Dissection is then continued along the anterior face of the orbital septum until the inferior orbital rim is reached. This approach with an intact septum avoids spilling orbital fat into the surgical field. (Reprinted with permission from Leatherbarrow B.[3])
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Fig. 10 Steps of the transconjunctival approach. A 4–0 silk traction suture is passed through the lower eyelid margin and the lower eyelid is everted. An incision is commenced 3–4 mm below the inferior border of the tarsus (A). Bovie cautery is used to incise through the conjunctiva and lower eyelid retractors (B). Traction sutures are placed through the inferior edge of the incision to allow for improved visualization (C). (Reprinted with permission from Leatherbarrow B.[3])
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Fig. 11 Once the conjunctiva and lower eyelid retractors are retracted up and outward, dissection is carried inferiorly to the orbital rim along the anterior face of the orbital septum. (Reprinted with permission from Freitag SK et al.[1])
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Fig. 12 Transconjunctival approach to lower eyelid blepharoplasty. Arrow points to orbital fat prolapsing through the opened septum. This prolapsing orbital fat will be excised. (Reprinted with permission from Leatherbarrow B.[3])
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Fig. 13 Transconjunctival approach to the orbital floor. After a transconjunctival incision below the inferior border of the tarsus has been made, and dissection along the anterior face of the orbital septum has been performed, the orbital rim is exposed. Bovie cautery is used to incise the periosteum (A) and a Freer elevator is used to lift the periosteum to expose the orbital floor (B). (Reprinted with permission from Leatherbarrow B.[3])

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Advantages of this Approach

This approach is quick, relatively bloodless, and has a small incision that is well camouflaged and without a skin incision. It can be combined with other incisions such as a transcaruncular incision or a lateral canthotomy incision. A reconstruction with bone flaps, plates, screws, and drills is not needed.


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Limitations of this Approach

As with the transcaruncular approach, the space in which one works is small, and it can be difficult to remove very large or very posterior masses. Use of a headlight by the primary surgeon is highly recommended for best visibility.


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Complications

Complications of this approach include vision loss, retrobulbar hemorrhage, cranial nerve V2 hypoesthesia from injury to the infraorbital nerve, injury to the inferior rectus or inferior oblique muscles, diplopia, scarring of the inferior fornix, pyogenic granuloma, symblepharon, cicatricial eyelid malposition including lower eyelid retraction, and lower eyelid entropion ([Table 2]).


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Transconjunctival Approach to the Orbit through the Bulbar Conjunctiva

Indications

A transconjunctival approach through the bulbar conjunctiva is often utilized in ophthalmic surgery. It is less commonly used for accessing tumors, and is more commonly employed for repairing open globe injuries, accessing the extraocular muscles for strabismus surgery, optic nerve sheath fenestration, enucleating globes, and for corneal neurotization (rerouting of the supraorbital or supratrochlear nerves to the cornea). The transconjunctival approach through the bulbar conjunctiva allows access to the space immediately along the surface of and directly behind the globe. This approach is unlikely to be used in collaboration with a neurosurgeon or sinus surgeon.


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Anatomy and Landmarks

The bulbar conjunctiva covers the surface of the globe and is continuous with the forniceal and palpebral conjunctiva as well as the corneal epithelium ([Fig. 14]). Deep to the bulbar conjunctiva lies a thicker connective tissue fascial layer called Tenon's capsule (fascia bulbi).[12] Tenon's capsule envelops the globe and is pierced by the extraocular muscles, forming fascial sleeves around them ([Fig. 15]). Anteriorly, approximately 3-mm posterior to the corneoscleral limbus, Tenon's capsule fuses with the intermuscular septum of the extraocular muscles. The most anterior connective tissue portions of Tenon's capsule blend together with the substantia propria of the conjunctiva such that at the corneoscleral limbus they are one layer. To access the surface of the globe, one must past through both conjunctiva and Tenon's capsule, although if an incision is made close to the limbus, sub-Tenon's space can be immediately accessed ([Fig. 16])

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Fig. 14 The bulbar conjunctiva covers the surface of the globe and is continuous with forniceal and palpebral conjunctiva as well as the corneal epithelium. Deep to the bulbar conjunctiva lies a thicker connective tissue layer called Tenon's capsule. (Reprinted with permission from Lang G.[13])
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Fig. 15 Tenon's capsule, best visualized after a globe has been enucleated (removed). Once the globe has been removed, a smooth fascial layer, Tenon's capsule, is appreciated. This layer forms a boundary separating the globe from the orbital fat. (Reprinted with permission from Leatherbarrow B.[3])
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Fig. 16 A conjunctival peritomy is initiated with Westcott scissors at the corneoscleral limbus through the conjunctiva. (Reprinted with permission from Freitag SK et al.[1])

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Steps to the Approach

  • General anesthesia is induced.

  • A small quantity of local anesthetic consisting of 2% lidocaine with 1:100,000 epinephrine mixed 1:1 with 0.75% bupivacaine can be injected subconjunctivally to balloon the perilimbal conjunctiva and Tenon's capsule and to assist with hemostasis.

  • An eyelid speculum is placed.

  • A transconjunctival incision is made through the conjunctiva and Tenon's capsule at the corneoscleral limbus with Westcott scissors ([Fig. 16]).

    • ▪ At this point, if exploration of an open globe injury is being performed, or if an enucleation or evisceration is being initiated, the peritomy is continued for 360 degrees around the corneal limbus with Stevens' scissors ([Fig. 17]).

  • Once the task at hand has been completed, hemostasis is ensured.

  • If the globe was not removed as part of the surgical procedure, the conjunctiva can be reapproximated to the corneal limbus with 8–0 polyglactin sutures.

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Fig. 17 After the peritomy has been performed, Stevens' tenotomy scissors are used to bluntly dissect between Tenon's capsule and the sclera along the surface of the globe. (Reprinted with permission from Freitag SK et al.[1])

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Advantages of this Approach

This approach allows access to a compartment that is immediately along the surface of the globe and not accessible via transcranial or transnasal approaches.


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Limitations of this Approach

Visualization of the posterior aspect of the globe may be difficult due to the small spaces. Care must be taken not to compress the globe to avoid ocular injury.


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Complications

Complications of this approach include vision loss,[9] retrobulbar hemorrhage, injury to the rectus muscles, diplopia, globe perforation, a permanently fixed pupil due to injury to the ciliary ganglion, symblepharon with restriction of extraocular motility, conjunctival scarring, and pyogenic granuloma formation ([Table 2]).


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Cases

Case 1

Vignette

A 15-year-old boy presented with eye pain, emesis, and bradycardia after being elbowed in the eye during a soccer match. Examination revealed pain and limitation in abduction and adduction. Computed tomography (CT) imaging demonstrated a medial orbital wall blow-out fracture with an entrapped medial rectus muscle, resulting in oculocardiac reflex ([Fig. 18]).

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Fig. 18 Axial and coronal computed tomography images demonstrating a small portion of the medial rectus muscle (arrows) entrapped in a medial wall fracture.

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Which Approach Would You Take?

Transcaruncular.


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Outcome

A transcaruncular approach to the medial orbital wall was emergently taken. The entrapped medial rectus muscle was visualized and released by elevating it with the Freer elevator and removing impinging fragments of bone with a Kerrison rongeur. Once the muscle was freed, a piece of Gelfilm was placed over the bony defect. Forced ductions revealed that the globe was now able to freely move. The incision did not require closure. Ophthalmic antibiotic ointment was applied and the patient went home after recovering from anesthesia.


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Case 2

Vignette

A 79-year-old diabetic woman, with a history of a liver transplant, glaucoma, and Graves' disease presented with rapidly progressive proptosis, worsening visual acuity, dyschromatopsia, and constricted visual fields, consistent with thyroid eye disease. CT imaging revealed severely enlarged extraocular muscles with apical crowding, and clinical evaluation confirmed compressive optic neuropathy ([Fig. 19]). Given the severity of her vision loss and medical comorbidities, orbital decompression of the medial wall and floor was felt to be the best option.

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Fig. 19 Preoperative coronal computed tomography imaging in a patient with severe thyroid eye disease demonstrating bilateral enlarged extraocular muscles with apical crowding.

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Which Approach Would You Take?

Transcaruncular.


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Outcome

Bilateral transcaruncular medial and inferior orbital decompressions were performed. A transcaruncular incision was made to access the medial orbital wall. The bone of the medial orbital wall was outfractured with the Freer elevator and pieces of bone were removed. Through the same incision, the medial portion of inferior orbital wall was outfractured into the maxillary sinus and portions of bone were removed, with care to identify the infraorbital canal and avoid injury to the infraorbital nerve. The conjunctival incision was closed on each side with one 7–0 polyglactin suture. Postoperative imaging revealed that although there was increased volume in the anterior orbit, there was still crowding in the orbital apex ([Fig. 20]). The posterior orbit is challenging to decompress via a transcaruncular approach, and for posterior decompressions, an endoscopic endonasal approach is often beneficial.

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Fig. 20 Postoperative coronal computed tomography imaging demonstrating bilateral increased orbital volume anteriorly as a result of orbital decompression, but persistent crowding in the orbital apex. For access to the posteromedial orbit for a posterior decompression, the transnasal endoscopic approach is beneficial.

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Case 3

Vignette

A 15-year-old boy presented to the eye emergency room with blurry vision after being shot with a BB gun in the face. An entrance wound was seen along the right nasal side-wall ([Fig. 21]). Ophthalmic examination was notable for mildly decreased visual acuity (20/40) in the right eye, an elevated right intraocular pressure (36 mm Hg), right microhyphema (blood in the anterior chamber of the eye), and superonasal retinal whitening (commotio retinae) with overlying vitreous hemorrhage but no evidence of open globe injury. CT imaging confirmed the presence of a BB in the right superonasal orbit, immediately adjacent to the globe and the insertion of the medial rectus muscle ([Fig. 21]).

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Fig. 21 BB gun injury in a teenage boy. External photograph demonstrating the entrance wound along the right nasal sidewall. Clinical examination ruled out an open globe injury. Coronal, sagittal and axial computed tomography imaging showed that the BB had lodged in the right orbit along the superomedial surface of the globe, near the insertion of the medial rectus muscle.

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Which Approach Would You Take?

Transconjunctival, after allowing the globe time to recover from other injuries.


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Outcome

Given the anterior location of the BB, and the possibility that the patient may need magnetic resonance imaging (MRI) at some point in his lifetime, a decision was made to remove the BB several months after the hyphema, retinal commotio, and vitreous hemorrhage had resolved. A transconjunctival approach was taken. A nasal conjunctival peritomy was performed. Blunt dissection was performed in the superonasal quadrant in the sub-Tenon's plane with curved Stevens' tenotomy scissors. The BB was encountered and freed from the surrounding tissues. The conjunctival peritomy was closed with two polyglactin sutures. Note that not all BBs need to be removed from the orbit. In particular, BBs in the posterior orbit are often left in place as they are rather inert.


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Case 4

Vignette

A 35-year-old woman with a history of neurofibromatosis type II presented with progressively worsening intermittent vertical diplopia and blurry vision. Clinical examination revealed superior displacement of right globe. CT imaging demonstrated an extraconal mass in her inferolateral orbit ([Fig. 22]), which was thought to be most consistent with a schwannoma.

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Fig. 22 computed tomography axial and sagittal images demonstrating an inferolateral extraconal well-demarcated right orbital mass (arrows). The mass was removed via a transconjunctival incision in the inferior fornix and was found to be a schwannoma.

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Which Approach Would You Take?

Transconjunctival through the inferior fornix.


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Outcome

A transconjunctival incision was made. Dissection was carried along the inferior orbital floor. The inferolateral periorbita was incised to enter the extraconal fat. The tumor was visualized and separated from the surrounding fat with blunt dissection using cotton-tipped applicators. The tumor was found to be unattached to any neurovascular structures and was removed. Histopathologic examination confirmed a schwannoma. Postoperatively she did well, without diplopia or visible cutaneous scarring.


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Case 5

Vignette

A 51-year-old woman presented with a well-circumscribed, enlarging predominantly intraconal orbital mass ([Fig. 23]). The preoperative diagnosis was felt to be most consistent with a benign neoplasm, likely a solitary fibrous tumor or schwannoma.

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Fig. 23 Preoperative axial and coronal computed tomography images demonstrating a large predominantly intraconal left orbital mass. The mass directly contacts the posterior aspect of the globe resulting in significant proptosis.

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Which Approach Would You Take?

Combined transcaruncular and transnasal approach.


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Outcome

A transnasal, transseptal endoscopic approach to the medial orbit was taken to allow for bimanual instrumentation in the sinuses. The medial aspect of the tumor was thus exposed and freed from attachments. A transcaruncular incision was also created to allow for dissection of the lateral portion of the tumor from surrounding structures. The tumor was then pushed from the orbital side toward the ethmoid sinus, while being pulled from the endoscopic trans-ethmoidal approach, delivering the tumor through the nose. Histopathology revealed a solitary fibrous tumor. The patient did well postoperatively and was able to avoid a traditional craniotomy approach to this large mass extending to the posterior orbit. ([Fig. 24]).

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Fig. 24 Postoperative axial and coronal magnetic resonance imaging after combined transnasal and transcaruncular removal of the orbital mass. Postoperative changes are noted in the sinuses and orbit; the mass has been removed in its entirety.

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Conflict of Interest

Dr. Freitag reports textbook royalties from Springer and Thieme. Consultant and Advisory Board for Horizon Therapeutics USA, Inc.


Address for correspondence

Natalie Wolkow, MD, PhD
Department of Ophthalmology, Ophthalmic Plastic Surgery Service, Massachusetts Eye and Ear, Harvard Medical School
Boston, MA
United States   

Publication History

Publication Date:
09 September 2020 (online)

© 2020. Thieme. All rights reserved.

Georg Thieme Verlag KG
Stuttgart · New York


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Fig. 1 Anatomy of the caruncle and surrounding structures. The caruncle is a nonkeratinized fleshy piece of tissue in the medial-most aspect of the palpebral fissure. Lateral to the caruncle is a fold of conjunctiva called the plica semilunaris. Superior and inferior to the caruncle within the eyelid margin are the canaliculi of the nasolacrimal system.
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Fig. 2 Anatomy posteromedial to the caruncle. Axial CT imaging of a normal right orbit. The lacrimal sac is highlighted in yellow. The posterior lacrimal crest is indicated in blue. The approximate locations of the anterior and posterior ethmoid arteries are indicated in red. CT, computed tomography.
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Fig. 3 Local anesthetic is infiltrated into the caruncle with a ½ inch 30-gauge needle on a 3-cc syringe. (Image courtesy: Kevin Ma, MD)
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Fig. 4 A scleral shell is inserted to protect the ocular surface from injury during surgery. (Image courtesy: Kevin Ma, MD)
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Fig. 5 The transcaruncular incision is made through the posterior one-third of the caruncle, or immediately posterior to the caruncle with Westcott scissors. (Image courtesy: Kevin Ma, MD)
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Fig. 6 Blunt dissection is continued through an avascular plane with Stevens’ scissors to the posterior lacrimal crest. (Image courtesy: Kevin Ma, MD)
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Fig. 7 At the conclusion of the procedure the globe is inspected to ensure that there have been no injuries. The transcaruncular incision is often well-approximated (as in this case), and can be left to self-seal without sutures or closed with one or two interrupted dissolvable sutures. (Image courtesy: Kevin Ma, MD)
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Fig. 8 Sagittal cross-sectional anatomy of the eyelids and globe. The conjunctiva covers the surface of the globe, the fornices and the internal aspect of the eyelids. (Reprinted with permission from Freitag SK et al.[1])
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Fig. 9 Transconjunctival approach to the orbital floor. A transconjunctival incision is typically initiated 3–4 mm below the inferior border of the tarsus through the conjunctiva and lower eyelid retractors. Dissection is then continued along the anterior face of the orbital septum until the inferior orbital rim is reached. This approach with an intact septum avoids spilling orbital fat into the surgical field. (Reprinted with permission from Leatherbarrow B.[3])
Zoom Image
Fig. 10 Steps of the transconjunctival approach. A 4–0 silk traction suture is passed through the lower eyelid margin and the lower eyelid is everted. An incision is commenced 3–4 mm below the inferior border of the tarsus (A). Bovie cautery is used to incise through the conjunctiva and lower eyelid retractors (B). Traction sutures are placed through the inferior edge of the incision to allow for improved visualization (C). (Reprinted with permission from Leatherbarrow B.[3])
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Fig. 11 Once the conjunctiva and lower eyelid retractors are retracted up and outward, dissection is carried inferiorly to the orbital rim along the anterior face of the orbital septum. (Reprinted with permission from Freitag SK et al.[1])
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Fig. 12 Transconjunctival approach to lower eyelid blepharoplasty. Arrow points to orbital fat prolapsing through the opened septum. This prolapsing orbital fat will be excised. (Reprinted with permission from Leatherbarrow B.[3])
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Fig. 13 Transconjunctival approach to the orbital floor. After a transconjunctival incision below the inferior border of the tarsus has been made, and dissection along the anterior face of the orbital septum has been performed, the orbital rim is exposed. Bovie cautery is used to incise the periosteum (A) and a Freer elevator is used to lift the periosteum to expose the orbital floor (B). (Reprinted with permission from Leatherbarrow B.[3])
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Fig. 14 The bulbar conjunctiva covers the surface of the globe and is continuous with forniceal and palpebral conjunctiva as well as the corneal epithelium. Deep to the bulbar conjunctiva lies a thicker connective tissue layer called Tenon's capsule. (Reprinted with permission from Lang G.[13])
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Fig. 15 Tenon's capsule, best visualized after a globe has been enucleated (removed). Once the globe has been removed, a smooth fascial layer, Tenon's capsule, is appreciated. This layer forms a boundary separating the globe from the orbital fat. (Reprinted with permission from Leatherbarrow B.[3])
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Fig. 16 A conjunctival peritomy is initiated with Westcott scissors at the corneoscleral limbus through the conjunctiva. (Reprinted with permission from Freitag SK et al.[1])
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Fig. 17 After the peritomy has been performed, Stevens' tenotomy scissors are used to bluntly dissect between Tenon's capsule and the sclera along the surface of the globe. (Reprinted with permission from Freitag SK et al.[1])
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Fig. 18 Axial and coronal computed tomography images demonstrating a small portion of the medial rectus muscle (arrows) entrapped in a medial wall fracture.
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Fig. 19 Preoperative coronal computed tomography imaging in a patient with severe thyroid eye disease demonstrating bilateral enlarged extraocular muscles with apical crowding.
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Fig. 20 Postoperative coronal computed tomography imaging demonstrating bilateral increased orbital volume anteriorly as a result of orbital decompression, but persistent crowding in the orbital apex. For access to the posteromedial orbit for a posterior decompression, the transnasal endoscopic approach is beneficial.
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Fig. 21 BB gun injury in a teenage boy. External photograph demonstrating the entrance wound along the right nasal sidewall. Clinical examination ruled out an open globe injury. Coronal, sagittal and axial computed tomography imaging showed that the BB had lodged in the right orbit along the superomedial surface of the globe, near the insertion of the medial rectus muscle.
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Fig. 22 computed tomography axial and sagittal images demonstrating an inferolateral extraconal well-demarcated right orbital mass (arrows). The mass was removed via a transconjunctival incision in the inferior fornix and was found to be a schwannoma.
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Fig. 23 Preoperative axial and coronal computed tomography images demonstrating a large predominantly intraconal left orbital mass. The mass directly contacts the posterior aspect of the globe resulting in significant proptosis.
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Fig. 24 Postoperative axial and coronal magnetic resonance imaging after combined transnasal and transcaruncular removal of the orbital mass. Postoperative changes are noted in the sinuses and orbit; the mass has been removed in its entirety.