Ординатура / Офтальмология / Английские материалы / Surgical Atlas of Orbital Diseases_Mallajosyula_2009

Figure 20.2F: Inferior cantholysis is performed

Figure 20.2H: The plane between the orbicularis muscle and the orbital septum is dissected to the inferior orbital margin. Desmarre's retractors are used to give traction and expose the tissues

Figure 20.2G: A conjunctival incision is made a few millimeters below the inferior tarsal margin

Figure 20.2I: The periosteum is cut 4 mm from the orbital margin with a radiofrequency monopolar electrode

Figure 20.2J: Using a Freer elevator the periosteum is lifted up and access to the inferior orbit is achieved

Figure 20.2K: The orbital mass is isolated and separated from the adjoining structures

Figure 20.2L: A pink firm well defined mass was removed from the inferior orbit

Figure 20.2N: The edges of the periosteum are sutured with 6/0 vicryl interrupted sutures

Figure 20.2M: The cut edges of the periosteum are then isolated

Figure 20.2O: The conjunctiva is closed with interrupted 6/0 vicryl sutures and the lateral canthotomy is repaired by using 6/0 prolene sutures to secure the tarsus to the lateral orbital periosteum

Figure 20.2P: Closure is performed in 2 layers with 6/0 vicryl for the soft tissues and 6/0 prolene for the skin

Figure 20.2Q: One week post surgery, there is minimal lid edema and the wound is well apposed. Histopathological examination revealed it was a degenerated parasitic cyst with chronic inflammation and calcification. The child had an uneventful recovery thereafter

Case 2

(Modified Stallard Wright orbitotomy)

A 30-year-old female presented with gradually increasing protrusion of the left eye for one year associated with diplopia followed by progressive loss of vision, watering, redness and pain in the eye. On clinical examination, she had severe non-axial proptosis measuring 12 mm with lateral displacement of the globe (Figure 20.3A). There was protrusion of orbital fat through the orbital septum. The mass was palpable and seemed to encompass the globe. It was firm in consistency, with mild tenderness. There was severe restriction of eye movements, lagophthalmos and exposure keratopathy. Fundus examination showed a pale optic disc with blurred margins and

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collateral vessels on the disc. CT scan showed an irregular intraconal mass; optic nerve could not be seen separately (Figures 20.3B and C). The mass showed specks of intralesional calcification and was causing distortion of the globe and medial orbital wall indicative of a large optic nerve sheath meningioma. Incision biopsy was done through a subbrow incision which confirmed the diagnosis of meningioma. As there was no optic canal or intracranial extension, it was decided that debulking of the mass would restore the eye to its natural position although the eye was blind. Debulking was subsequently done through a lateral orbitotomy approach (modified Stallard-wright incision).

Steps of Surgery

Figure 20.3A: A 30-year-old lady presented with progressive proptosis of the left eye with downward and lateral displacement of the globe

Figure 20.3B: CT scan (coronal section) showed a large, irregular, hyperdense mass behind the left globe

Figure 20.3E: The skin incision is made with a no 11 Bard Parker blade. The incision starts from just below the lateral aspect of the brow and ends in a rhytid over the anterior zygomatic arch

Figure 20.3G: The periosteum is cut with a monopolar probe about 4 mm behind the orbital rim starting superiorly and ending inferiorly just above the zygomatic arch

Figure 20.3F: Under stretch and lifting the tissues, the subcutaneous tissue is dissected down to the periosteum

Figure 20.3H: The periosteum is then reflected. The periorbita is also lifted away from the orbital bone upto the anterior one third of the orbit

Figure 20.3J: Incision lines are made on the bone about 3 mm above the frontozygomatic suture superiorly and just above the zygomatic arch inferiorly. A Desmarre's retractor is placed to pull the skin and subcutaneous tissue laterally and a lid guard is placed inside the orbit to protect the contents of the orbit. Using an oscillating saw, cuts are made along the incision lines on the bone. Irrigation is performed as the saw is being used

Figure 20.3K: Once the cut have been made, the bone fragment is held with a bone rongeur and moved back and forth until it fractures posteriorly

Figure 20.3N: The cut edges of the periorbita are grasped and gently spread apart to extend the cut posteriorly

Figure 20.3O: Retractors are used to keep the orbital fat away and dissection of the mass is performed by blunt dissection

Figure 20.3P: A reddish friable firm mass was removed from the orbit

Figure 20.3R: The subcutaneous tissue is apposed with 6/0 vicryl sutures

REFERENCES

1.Wright JE et al. Continuous monitoring of the visual evoked response during intraorbital surgery. Trans Ophthalmol Soc UK. 1973;93:311.

2.Putterman A, Goldberg MF Retinal cryoprobe in orbital tumour management. Am J Ophthalmol 1975;80:88.

3.Leone CR Surgical approaches to the orbit. Ophthalmology 1979;86:930.

4.Benedict WL Surgical treatment of tumours and cysts of the orbit. Eleventh de Schweinitz lecture. Am J Ophthalmol 1949;32:763-73.

5.Smith B The anterior surgical approach to orbital tumours. Trans Am Acad Ophthalmol Otolaryngol 1966;70:607-11.

6.Mc Cord CD Jr Orbital decompression for Graves' disease. Exposure through lateral canthal and inferior fornix incision. Ophthalmology 1981;88:533-41.

Figure 20.3Q: The periorbita is closed with interrupted 6/0 vicryl sutures

Figure 20.3S: The skin is closed with continuous 6/0 prolene suture. The patient was doing well at last follow-up

7.Berke RN Modified Kronlein operation. AMA Arch Ophthalmol 1954;51:609-32.

8.Wright JE Surgical exploration of the orbit. Trans Ophthalmol Soc UK 1979;99:238-40.

9.Simonton JT, Garber PF, Ahl N Margins of safety in lateral orbitotomy. Arch Ophthalmol 1977;95:1229-31.

10.Maroon JC, Kennerdell JS. Microsurgical approach to orbital tumours. Clin Neurosurg 1979;26:479-89.

11.Shucart W Transfrontal approach to the orbit. In Hornblass A(ed): Tumours of the Ocular Adnexa and Orbit St Louis, CV Mosby, 1979.

12.Love JG, Benedict WL Transcranial removal of intraorbital tumours. JAMA 1945;121:777-84.

13.Schurmann K, Oppel O. Transfrontal orbitotomy as a method of operation in retrobulbar tumours. Klin Monatsbl Augenheikld 1961;139:130-59.

14.Long JC, Ellis PP Total unilateral visual loss following orbital surgery. Am J Ophthalmol 1971;71:218-20.

Introduction

The orbit is located between the facial structures, paranasal sinuses and the skull base. Some of the bony walls that separate the orbit and the paranasal sinuses are very thin. Orbit is in direct communication with brain through the optic canal. Various pathological lesions extend from these surrounding structures in to the orbit and vice versa. Rarely the lesion can involve the sinuses, orbit and the brain, like sino-orbito-cranial mucormycosis. Thus orbit is an area of interest for several other surgical specialties like ENT specialist and neurosurgeon. Ophthalmic surgeons can deal with orbit by a number of direct orbital approaches. ENT surgeons can gain access to pathological conditions arising with in the air sinuses through percutaneous approaches, oral cavity or endonasal endoscopic approaches. Neurosurgeons can access to those tumors that invade both the intracranial and orbital space. A detailed discussion of these lesions is beyond the scope of this book. However we review the various ENT and neurological lesions that may present with proptosis and outline various surgical approaches towards managing these lesions.

Surgical Anatomy

The orbital cavity is a 30 ml pear shaped; four walled structure. The central axis of the orbit and the visual axis of the globe are separated by 23 degrees.

The medial wall is formed by the lacrimal and ethmoidal bones along with body of the sphenoid bone.

Lateral wall of the orbit is formed by zygomatic bone and greater wing of sphenoid, floor is formed zygomatic, maxillary and palatine bones and roof is formed by horizontal portion of the frontal bone and by the lesser wing of the sphenoid bone.

The optic canal: A tubular cavity lying in the deepest portion of the orbit enters the cranial cavity medial to the anterior clinoid process. The optic canal measures an average 5 to 10 mm long, 4.5 mm wide and 5 mm in height.

The thickness of the medial wall of the optic canal is an important surgical consideration in the transethmoidal and transsphenoidal approaches to the canal. In about 12% of cases the medial wall of the optic canal is bordered not by the sphenoid sinus but by a posterior or superior ethmoidal air cell. The inclination angle of the optic canal relative to its surroundings is practically important concern.

For the superior orbital fissure, through which the intracranial duramater joins the periorbita, medial margin is formed by the lesser wing of the sphenoid and greater wing of sphenoid forms the lateral margin.

Optic nerve has a flattened longitudinal shape, measure approximately 4 × 6 mm. As it enters the cranial end of the optic canal, it is circular and 5 mm in diameter, and continues to the globe as a 6 × 4 mm vertically oval structure.

The intracranial pia and arachnoid accompanies the nerve from the chiasm and both fuse at the globe. There are loose trabeculations in the subarachnoid space.

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The annulus of Zinn forms the tendinous insertion of the extraocular muscle cone at the apex. It spans the superior orbital fissure creating an intraconal and extraconal compartment of the fissure, dissecting the structures that run through it.

ENT APPROACH TO PROPTOSIS

The paraorbital region represents the paranasal air sinuses surrounding the orbit. Tumors of the orbit and paraorbital region sometimes distort the natural architecture of the eye. Although proptosis may seem to be primarily the concern of the ophthalmologist, because of the close proximity of the orbit and para nasal sinuses and various connecting fissures and foramina between the two, many ENT lesions may present with proptosis.

Various Etiological Factors of Proptosis in ENT

There are various etiological factors of interest to the otolaryngologists, which can cause proptosis.

Diseases can be classified as follows:

a.Diseases of the orbit caused by the inflammation in Paranasal sinuses.

b.Tumors of the orbito-sinual-region.

c.Diseases of the lacrimal apparatus secondary to sinonasal diseases.

a.Infection and inflammation

A variety of inflammatory and infective sinonasal conditions may impinge on the orbit; the commonest of which are as follows:

1.Acute purulent sinusitis

2.Gross polyposis-particularly when it begins at an early age

3.Fungal infections

4.Mucocele-commonest is frontoethmoidal mucocele.

b.Tumors of the orbito–sinual disease

The Paranasal sinuses tumors are classified into benign and malignant.

Benign Paranasal sinus tumor

A.Epithelial tumors:

1.Papilloma

2.Inverting papilloma

3.Tumors of minor salivary glands

B.Angiomatous tumors:

1.Juvenile nasopharyngeal angiofibroma

2.Hemangiopericytoma

3.Lymphangioma

C.Mesenchymal tumors:

1.Fibrous dysplasia

2.Osteomas

D.Odontogenic tumors: Ameloblastoma

E.Neurogenic tumors

1.Schwannoma

2.Neurofibroma

Malignant paranasal sinus tumors

A.Epithelial tumors

1.Squamous cell carcinoma

2.Adenoid cystic carcinoma

3.Esthesioneuroblastoma

4.Malignant melanoma of sinonasal tract

B.Lymphoreticular tumors:

1.Lymphoma–Non-Hodgkin's

2.Extramedullary plasmacytoma

C.Mesenchymal tumors:

1.Osteogenicsarcoma

2.Rhabdomyosarcoma

3.Fibrosarcoma

4.Chondrosarcoma

c. Diseases of the lacrimal apparatus

1.Chronic dacryocystitis

2.Tumors of the lacrimal apparatus

Clinical Manifestations and Evaluation

The most common problems the patients complained are

a.Proptosis

b.Nasal obstruction

c.Epistaxis

d.Reduced vision

e.Facial swelling

f.Nasal discharge

g.Redness of eye

h.Diplopia

After thorough ENT clinical examination the patients presented with following manifestations.

•Proptosis

•Nasal mass

•Restricted eye movements

•Septal deviations

•Facial swelling

•Reduced vision

•Naso-pharyngeal mass

•Congestion of the eye

•Nasal discharge

A. Sinus Diseases Causing Proptosis

Purulent infections

Most of the bacterial infections in the orbit are caused by the spread through infections of the paranasal sinuses (Figures 21.1A and C).

Spread of infection to the orbit is through valve less veins, and direct spread through lamina papyracea.

The most common organisms involved in this

disease are Streptococcus pneumoniae, H. influenza, Beta-hemolytic Streptococci, Staph. Aureus. Ethmoid sinus is most commonly involved.

Treatment

High dose, intravenous broad spectrum antibiotics for 2 weeks along with nasal decongestants.

Surgical decompression and drainage if necessary.

Extensive nasal polyposis

Ethmoidal polyps can be seen in individuals having history of allergy. This condition is most common in Indians especially males. Patient presents with bilateral nasal obstruction, nasal discharge, hypo/

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anosmia, epistaxis and eccentric proptosis. Diagnosis is by CT scan of paranasal sinuses. Medical treatment includes nasal steroidal sprays. Surgical treatment includes intranasal polpectomy, intranasal ethmoidectomy, external ethmoidectomy and FESS.

Mucormycosis

This is a fulminant opportunistic infection caused by saprophytic fungi of the order mucorales, commonly seen in immunocompromised patients (Figures 21.2A and B).

It occurs as rhinocerebral, pulmonary, ocular, superficial and disseminated forms.Rhinocerebral is again subdivided into rhinomaxillary and rhinoorbitocerebral form. It is characterized by bloody nasal discharge, facial swelling, proptosis, altered mental status, palatal or gingival necrosis, facial nerve palsy. Dry black crust is seen in the inferior turbinate, septum and palate. In advanced cases brain and major vascular structures in the head can be involved. This condition is diagnosed by CT scan and frozen sections. This is treated by controlling the underlying predisposing factors, immediate debridement of all devitalized tissues and IV amphotericin.

Allergic fungal sinusitis

This condition occurs when an atopic individual is exposed to inhaled fungi. The fungi deposited in the sinus cavity initiate the immunological reactions, causing mucosal edema, stasis of the secretions, and inflammatory exudates blocking the sinus ostia. This process may expand to involve adjacent sinuses and may produce sinus expansion and bony erosion. Secondary bacterial infection can supervene.

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The patient presents with nasal congestion, rhinorrhea, headache, epistaxis, and eccentric proptosis. This condition can be diagnosed by raised serum IgE levels, PAS stain, KOH mounting, CT scans of PNS. Treatment includes steroid therapy, surgical debridement and creating permanent drainage.

Frontoethmoidal mucoceles

It is an epithelial lined, mucus containing sac filling the sinus and capable of expansion. Frontal and ethmoidal sinuses are most commonly affected. Secondary bacterial infection may change these to pyoceles. These are formed due to obstruction of the affected sinus and inflammation. Patient presents

Figures 21.2A and B: A case of mucormycosis with proptosis and severe ptosis of right eye. MRI (B) shows the involvement of maxillary, ethmoid and frontal sinuses. Note intracranial and orbital extensions

Figures 21.3A and B: A case of allergic fungal sinusitis with involvement of the anterior and posterior ethmoid sinuses and a huge orbital extension (B) which is causing a severe eccentric proptosis of the right eye (A)

Figures 21.4A and B: Eccentric proptosis of left eye (A) with the globe pushed down and out. Note the infected ethmoid sinus (B)

with proptosis, headache, and facial pain. This condition is diagnosed by CT scans. This condition can be treated surgically by external ethmoidectomy/ FESS.

B. Tumors of Paranasal Sinuses Causing Proptosis

•Benign tumors

•Inverted papilloma

Lateral wall of the nose is the most common site. There is proliferation of the covering epithelium and extensive finger like inversions into the underlying stroma of the epithelium. Patient presents with nasal obstruction, epistaxis, and proptosis. This condition is premalignant. This condition can be diagnosed by CT scan. Treatment of choice is surgery either by lateral rhinotomy and medial maxillectomy or mid facial degloving.

Fibrous dysplasia

Fibrous dysplasia is a skeletal developmental anomaly of the bone-forming mesenchyme that manifests as a defect in osteoblastic differentiation and maturation.

The following 4 disease patterns are recognized:

•Monostotic form

•Polyostotic form

•Craniofacial form

•Cherubism

Monostotic form is the most common type(70-80%). Sites of involvement most commonly include the frontal, sphenoid, maxillary, and ethmoidal bones. Hypertelorism, cranial asymmetry, facial deformity, and proptosis may occur because of involvement of orbital and periorbital bones. However visual impairment, leading to blindness is rare. Involvement of the sphenoid wing and temporal bones may result in vestibular dysfunction, tinnitus, and hearing loss. When the cribriform plate is involved, hyposmia or anosmia may result. Diagnosis is by X-rays and CT scans. Treatment is by local excision.

Hemangiopericytoma

It is of vascular origin arising from Zimmermann pericyte cell. Patient presents with nasal obstruction, epistaxis, and proptosis. Distant metastasis is common to lungs, liver and bone. Diagnosis is