Ординатура / Офтальмология / Английские материалы / Oculoplasty and Reconstructive Surgery Made Easy_Garg,Touky, Nasralla_2009
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Orbital Disorders—Vascular Abnormalities 309
Management
Surgical debulking is the treatment of choice.
Prognosis
It is difficult to remove tumor en toto, due to its nonencapsulated nature. Surgery may be complicated with bleeding and recurrence.
CAVERNOUS HEMANGIOMA
These are benign well encapsulated vascular tumor.
Symptoms and Signs
They may be present at birth but usually present later (Figure 4A). They gradually increase in size manifesting as proptosis and visual impairment.
Investigations
Diagnosis is established by ultrasonography and CT scan, which demonstrates well encapsulated intraconal cystic lesion
(Figure 4B).
Figures 4A and B: (A) A 13-year-old girl presented with R/E axial proptosis. (B) CT scan showing well encapsulated intraconal mass
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Management
Removal of mass en toto via orbitotomy.
Prognosis
Prognosis is excellent. Recurrence are rare even with incomplete resection.
ORBITAL VARICES
It is the most common congenital venous malformation.
Symptoms and Signs
It usually present as intermittent proptosis with dilated conjunctival or lid vessels (Figure 5). They grow slowly during childhood and rarely cause visual problems, unless spontaneous hemorrhage occurs. The proptosis increases with Valsalva maneuver or while straining. It may present with bruit and pulsating exophthalmos mimicking caroticocavernous fistula (Figures 6A and B).
Figure 5: Showing dilated conjunctival vessels
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Figures 6A and B: Showing increase in proptosis following Valsalva maneuver
Investigations
DiagnosiscanbeestablishedbyorbitalvenographyorCTscan.
Management
Observation is warranted for small lesions. Surgical intervention may be necessary in non-resolving episodes of thrombosis, severe proptosis and optic nerve compression. Surgery can be extremely difficult, as varices are very friable and intimately intermixed with normal orbital structures.
Prognosis
Complete removal is not possible.There is also a significant risk of visual loss as a result of hemorrhage or optic nerve damage.
SUGGESTED READING
1.Henderson JW. Orbital tumors. Philadelphia:WB Saunders 1973.
2.Rootman J, Graeb DA. Vascular lesions. In: Rootman J, ed. Diseases of the Orbit. Philadelphia: Lippincott, Williams and Wilkins 1988:553-7.
3.Shields JA, Shields CL. Vascular and hemorrhagic lesions. In: Shields JA, Shields C, eds. Atlas of Orbital Tumors. Philadelphia: Lippincott, Williams and Wilkins 1999.
ORBITAL CELLULITIS
Introduction
Bacterial orbital cellulitis is one of the common causes of inflammatory proptosis. It is commonly associated with sinusitis. Other sources of infection are spread of infection to the orbit from the eyelid, after penetrating injury, endogenous in an immunocompromised or debilitated patient, or from a tooth infection.
Signs and Symptoms
The patient presents with acute onset, progressive painful proptosis, axial or non-axial. The patient may be febrile. The eyelids will show edema and mechanical ptosis. Ocular mobility will be limited. The conjunctiva may show chemosis, congestion, and conjunctival prolapse. In severe cases, pupil may show relative afferent pupillary defect. Fundus may show venous congestion, disc hyperemia and disc edema
(Figure 1A).
Investigation
Nasal swab and sinus drainage may yield material for identification of infective agent and antibiotic sensitivity.
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Figures 1A to D: (A) Clinical picture of patient with orbital cellulitis, showing proptosis, chemosis, restricted ocular movement, periocular edema and erythema. (B) Axial view of CT scan of orbital cellulitis, showing diffuse shadow with heterogeneous density and lucent pockets of gas formation, extraconal and intraconal. The ethmoid sinuses are opacified. (C) Clinical picture of same patient, deteriorating to orbital abscess. Proptosis, chemosis, limited ocular motility and periorbital edema are increasing. There is a localized, tense, fluctuant area of orbital abscess in the superonasal quadrant of the orbit. (D) Clinical picture of complete recovery of the patient after systemic antibiotics and drainage of orbital abscess
Orbital imaging helps to confirm the diagnosis and rule out orbital abscess formation. The optic nerve will appear straightened due to proptosis. The lids will be thickened and show soft tissue shadows. The orbit will show ill-defined soft tissue shadows, with increased density of intra-conal and extra-conal orbital fat. Anaerobic infection may show gas in orbit. The sinuses may show opacification or mucosal thickening (Figure 1B).
Differential Diagnosis
The condition should be differentiated from other causes of inflammatory orbital disease, and orbital abscess.
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Other non-inflammatory rapidly progressive painful proptosis may caused by orbital hematoma after trauma, or by hemorrhage into an orbital lymphangioma.
In children, orbital inflammation with proptosis should be carefully assessed to rule out an atypical presentation of retinoblastoma.
Treatment
Orbital cellulitis is treated by parenteral antibiotics. If the causative organism can be isolated, specific therapy should be started. Otherwise, the choice of antibiotic is empirical depending on the patient profile. Further investigations should be done, or abscess formation suspected if there is no improvement after 48 hours of starting therapy. The paranasal sinuses may need drainage, which will also aid in identification of causative organism.
The correct choice of antibiotics assumes greater importance due to the change in patterns of causative organisms in recent years. First, after the introduction of hemophilus vaccine, Hemophilus influenzae is no longer the commonest organism in children. Secondly, there is a growing prevalence of methicillin-resistant Staphylococcus aureus as a causative organism.
In childhood, sinusitis and orbital cellulitis tend to be due to a single aerobic organism such as Streptococcus, Moraxella or Hemophilus. In adults, the infection is often polymicrobial with mixed gram-positive and gram-negative bacteria, and aerobic and anaerobic organisms. Streptococcus and Staphylococcus are common. Frequently used antibiotics are the third generation cephalosporins, and vancomycin combined with gram-negative coverage. In methicillinresistant Staphylococcus aureus, the treatment is with trimethoprim-sulfamethoxazole, rifampin, clindamycin or vancomycin.
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ORBITAL ABSCESS
Introduction
Orbital abscess is usually a complication of orbital cellulitis. An orbital sub-periosteal abscess may develop rapidly from the adjacent paranasal sinus with minimal previous orbital cellulitis.
Signs and Symptoms
Progressive non-axial proptosis, worsening lid edema and chemosis of conjunctiva, severe limitation of ocular motility will be seen. Visual acuity may be diminished, with relative afferent pupillary defect. There may be a palpable fluctuant mass. The fundus examination may show disc edema and perivasculitis (Figure 1C).
Systemically, the patient may have increased fever spikes and malaise.
Investigation
On a CT scan a subperiosteal abscess is commonly adjacent to the paranasal sinuses, against the bony walls of the orbit, with homogeneous low density internal appearance, and smooth convex surface with contrast-enhancing capsule. An orbital abscess will have an intra-orbital mass with lower density areas internally, with or without a contrast-enhancing capsule; gas may be present in the orbit. Sinus opacification may be present (Figure 2).
Attempt should be made to isolate the organism as in orbital cellulitis. The organism can be better isolated from the purulent material obtained by draining the abscess.
Treatment
An orbital abscess in an adult or older child needs surgical drainage. After draining the pus completely, the abscess cavity
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Figure 2: Axial view of CT scan of subperiosteal orbital abscess. The abscess is located at the medial wall adjacent to the ethmoid sinus, has a low internal density, convex shape and enhancement of its rim after contrast injection
should be irrigated with antibiotic solution, and a tube drain placed. Children responding to antibiotics do not need sinus or abscess drainage.
Intensive systemic antibiotics as discussed under orbital cellulitis are administered.
Complications
Orbital cellulitis and orbital abscess may lead to visual loss, cranial nerve paresis, brain abscess and subdural empyema, superior ophthalmic vein thrombosis and cavernous sinus thrombosis.
CAVERNOUS SINUS THROMBOSIS
Introduction
Cavernous sinus thrombosis is a dreaded complication of orbital cellulitis, with high morbidity.
Signs and Symptoms
The patient is febrile, and may complain of headache. The sensorium may be affected in the late stages of the disease.
The patient has increasing proptosis, periorbital edema, chemosis and limitation of ocular movement. All extraocular muscles as well as the sphincter pupillae are affected. On
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fundus examination, papilledema, hyperemia and retinal hemorrhages are seen. Limitation of motility of the contralateral eye in a previously unilateral orbital cellulitis is indicative of cavernous sinus thrombosis. There may be loss of sensation in the distribution of the maxillary division of the trigeminal nerve, unlike in orbital cellulitis.
Investigations
Imaging of the orbit and parasellar region by CT scan or MRI will show bilateral enlargement of multiple extraocular muscles. The superior ophthalmic vein would be enlarged. The cavernous sinus would be enlarged and enhance with contrast; loss of the concavity of the lateral border of the sinus would be seen on an axial section. An MRI would show the loss of blood flow within the sinus (Figure 3).
Figure 3: Axial view of CT scan showing dilated cavernous sinus, enhancing with contrast; the lateral concavity is replaced by a convexity in cavernous sinus thrombosis
Treatment
Treatment of cavernous sinus thrombosis entails a team effort in conjunction with internal medicine, neuromedicine and infectious disease specialists. The therapy requires intravenous antibiotics and supportive care. In selected cases of sinus thrombosis from an infective cause, anticoagulants have a role in reducing the morbidity.
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ORBITAL TUBERCULOSIS
Introduction
Worldwide, tuberculosis causes significant morbidity and mortality; the incidence of tuberculosis, particularly multidrug resistant varieties has been on the rise. Orbital involvement with tuberculosis is rare. Orbital involvement is either secondary to hematogenous spread or by direct spread from neighboring structures such as the sinuses.
Signs and Symptoms
Orbital tuberculosis progresses slowly. It may present as a space-occupying lesion, causing proptosis, limitation of ocular motility, and a hard palpable mass. The mass effect may be caused by a tuberculoma or a cold abscess (Figures 4A and
B).
Figures 4A and B: (A) Clinical picture of patient with tubercular granuloma left orbit, showing inferior orbital mass which is tense and erythematous.
(B) Coronal CT scan of same patient, showing soft tissue density irregular mass in inferior orbit, with hypodense area corresponding to area of necrosis
Tuberculosis may also affect the orbital bones, causing osteomyelitis, with inflammation and discharging sinuses. Necrotizing infiltrating lesions may develop cutaneous fistulas (Figures 5A to D).