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

Figure 16.24: Visual fields showing inferior arcuate scotoma

Figure 16.25: CT after 4 months shows a cyst which is shrunken and does not show the scolex

Case 5

Master R, a boy of 8 years presented with pain, proptosis, drooping of left upper eye lid, since 4 days, associated with headache and nausea and diplopia.

There was no history of convulsions, vomiting or fever (Figure 16.26).

On examination, periocular fullness, more on superior quadrant with eyeball pushed down, minimal congestion of conjunctiva, and restricted ocular motility in vertical gaze leading to vertical diplopia were evident (Figure 16.27). The vision was 20/20, pupil was normal and optic disc showed mild hyperemia with filling up of the cup. There were no

Parasitic Cysts of Orbit 213

hemorrhages. Clinical diagnosis of myocysticercosis involving LPS-SR complex was made because of patients age, acute onset, with inflammatory signs, acquired ptosis, mild proptosis, and restricted ocular motility. In view of headache, nausea and early disc edema, the coexistence of neurocysticercosis was suspected.

On imaging, of the orbit, (Figures 16.28 and 16.29) a markedly enlarged LPS-SR complex was noted. A large cystic lesion was seen in relation to the thickened muscles. Scolex was made out in the cyst.

Imaging of the brain confirmed our suspicion. It revealed the presence of a calcified cyst in the brain parenchyma (Figure 16.30) with normal architecture of the surrounding brain. Typical " Coin Lesions" with surrounding edema of brain was noted in other parts (Figure 16.31). A total of 3 such active cysts were noted in the serial sections of the brain. The surrounding cerebral edema indicated that the cyst is live and active. Anticysticercosis antibodies were positive at 1.68 od units, as against the values of > 0.5 od units taken as positive. Most of the patients of neurocysticercosis present with convulsions. The unique features of this case are (1) absence of convulsions, (2) multiple cysts in the brain, three are active and one is inactive, association of orbital and neurocysticercosis.

In view of associated neurocysticercosis the child was referred to neurologist who treated him with Albendazole, Prednisolone and Carbamazepam. The child recovered well. Six weeks after initiating the treatment, the ptosis disappeared, and normal ocular motility was restored.The optic disc edema subsided completely. There was no recurrence during the last 2 years of follow up (Figure 16.32).

Figure 16.26: Periocular swelling, ptosis, mild eccentric proptosis with the globe pushed down in a child of 8 yrs. Onset was acute

Figure 16.28: CT showing a large cystic lesion in relation to

LPS-SR complex

Figure 16.29: Scolex in the cystic lesion

Figure 16.31: Axial imaging of brain shows the presence of typical

“coin lesion” with very severe edema surrounding the lesion. 2 more similar “active” lesions were seen in other sections of imaging

Case 6

We wish to share our experience with a unique clinical experience.

Mr. S 18 years presented with a swelling on his left eye of 4 days duration. He is a college student, doing his graduation. He gives history of mild pain and discomfort. There is no history of defective vision or diplopia. He noticed mild drooping of his left upper lid since 1 week, but did not pay attention due to his approaching examinations. However he noticed this morning that the swelling has enlarged and the discomfort has increased in intensity. His food habits include eating road-side junk food, raw vegetables and green salads.

On examination (Figure 16.33) but for very minimal fullness and 1 mm of ptosis of his left upperlid,the rest looked normal. Ocular motility was normal (Figures 16.34 and 16.35).

On elevating the upper lid, a cyst measuring 12 cm × 10 cm, and in relation to superior rectus was seen. Surrounding conjunctiva was congested. This is the typical appearance of cysticercosis in the sub-

Parasitic Cysts of Orbit 215

Figure 16.35: The ocular motility was normal. The elevation as you can see here is full. He is orthophoric on cover test

Figure 16.33: Anterior segment looks almost normal

Figure 16.34: Note the cyst in relation to superior rectus muscle.

Surrounding conjunctiva was congested

Figure 16.36: Spontaneously extruded cysticercosis in a container

tenon's space. The cyst is always in relation to an extraocular muscle. Most often the surrounding conjunctiva shows congestion. Since the cyst was very anteriorly placed, excision was planned and Mr. S was advised to come after 2 days to the operation room for excision of the cyst under local anesthesia. He attended the operation room after 2 days, carrying a small bottle in which he placed “something” that came from his affected eye that morning (Figure 16.36).

To our surprise the bottle contained cysticercosis cyst. This is an example of spontaneous extrusion.

Case 7

We are to share with you a very rare clinical presentation of cysticercosis, which we came across only once so far. The patient, master D a young boy of 12 years, was a student of class 7, and was from a

216 Surgical Atlas of Orbital Diseases

village, 80 miles away. He was brought with a history of sudden loss of vision of his left eye since 2 weeks. He complained of dull retro bulbar pain of 2 months duration. There was no history of trauma, fever or any other symptoms of systemic illness.

On examination, (Figure 16.37) there was mild proptosis of his left eye, which was more evident on Nafzeiger’s (Figure 16.38). The ocular motility was normal. The pupil was dilated with a very significant RAPD. The vision was reduced to PL only. Retropulsion was mildly positive.

Fundus Examination revealed optic disc which shows nasal hyperemia, and gross pallor on the temporal side, with exudates, macular fan and degenerative changes involving macula suggestive of neuroretinitis (Figure 16.39).

This child was referred to us in view of proptosis of his left eye. The association between proptosis and neuroretinitis is very unusual and difficult to explain. The fundus picture was more like a neuroretinitis rather than disc edema.

We discussed about the possibilities of a fungal infection extending from the sinuses with a vascular involvement, which could explain proptosis and sudden acute fall of vision (which is due to retinal

Figure 16.37: Presents with sudden loss of vision of his left eye

vascular obstruction) and could not explain neuroretinitis.

The possibility of cysticercosis was also discussed, but we were not for it as we did not come across such a clinical presentation.

Imaging by CT scan of orbit showed a large cyst in relation to the optic nerve and scolex could be very clearly seen (Figures 16.40 and 16.41).

Figure 16.39: Severe macular changes including macular fan, exudates and pallor of optic disc

Figure 16.40: Axial imaging of orbit shows a cyst in relation to optic nerve. Scolex is seen very clearly

Figure 16.38: Proptosis of left eye is better appreciated by Nafzeiger's test

Figure 16.41: Cyst involving optic nerve. Scolex could be seen in the center of the cyst

Anticysticercosis antibodies were positive which confirms the diagnosis of cysticercosis of optic nerve. The associated neuroretinitis was due to the severe inflammatory response produced by the toxins released, which was common with cysticercosis.

The child was treated with oral Albendazole and Prednisolone. Surgical excision of the cyst through the antero-lateral orbitotomy was not considered in view of the severe irreversible damage already occurred, and the very poor visual prognosis. With treatment, proptosis disappeared, but his vision was absent PL.

Hydatid Cyst of Orbit

Hydatid cyst is another parasitic infestation of the orbit, less common than cysticercosis. It is caused by echinococcus granulosus or the dog tapeworm. Dogs are the primary hosts with sheep and cattle being intermediary hosts. Humans are accidental hosts, acquiring infection by ingesting ova along with raw vegetables, contaminated water, or from direct contact with dogs. Embryos pass across duodenal mucosa to liver through the portal veins. Liver, lungs, and brain are primarily affected. Orbital disease is seen in only 1% of hydatid disease.12 Hydatid cysts form 0.3-5% of all orbital diseases.13,14

Hydatid infestation commonly presents in children and young adults. Most of the patients are below 16 years.13 Rarely elderly people are affected by this disease.

Proptosis is the most common presentation of orbital hydatidosis.14 Usually, the proptosis is of a few months duration, associated with mild pain or discomfort. Hydatid cysts are commonly located in the intraconal space. In our experience it is the most common cystic lesion of intraconal space. Since intraconal space is the most common location, it can present with defective vision associated with RAPD and optic disc edema. Other causes of defective vision in hydatid cyst we came across include refractive errors and corneal perforation due to exposure keratitis in one case. Other symptoms can be periorbital pain, chemosis and headache.12 Diplopia due to ocular motility restriction can be a rare symptom.15,16 In neglected and unattended long standing cases, these cyst grow to a very large size, deforming the globe (Figure 16.42).17 Diagnosis is by a high index of suspicion especially in endemic areas, and investigations like CT scan orbit. Sometimes

Parasitic Cysts of Orbit 217

Figures 16.42A and B: CT Scan of orbit showing a well encapsulated, intraconal Hydatid cyst (A) Severe proptosis and distorted globe with anterior staphyloma in a neglected case of Hydatid disease (B)

orbital hydatid may be a part of disseminated disease,18 with lung, liver and brain being commonly involved and hence in every case of hydatid cyst, ultrasound of abdomen and CT scan of chest and brain were advised.18,19

Investigations

•CBPusually normal

•Stool examination does not show ova or cysts

•Casoni's intradermal test is positive in 75% of the people13

•CIEPCounter immunoelectrophoresis

•Imaging techniques of importance are orbital ultrasonography and CT scan.

On ultrasound, diagnostic double wall sign is confirmatory, spoke wheel pattern and water lily sign are seen with cyst calcification.

CT scan shows well encapsulated cystic mass with cyst fluid showing attenuation values of 3-30 HU. The mass indents and deforms the globe. Calcification of the internal septa may be seen. We prefer CT scan of the orbit.

Microscopic analysis of the cyst fluid shows scolices and hooklets. The cyst wall is laminated and has the characteristic "coats of an onion" appearance.

Management: We prefer surgical excision of the cyst by performing orbitotomy . The cyst wall is very thin and can rupture during surgery. Hence, to prevent it, after exposing the cyst, we prefer to aspirate the contents, so that the cyst shrinks in size. Then it can be very safely pulled out with the help of a cryo. Akon O. et al from Turkey20 have advocated percutaneous aspiration of the cyst under ultrasonic guidance, followed by injection of 15% of hypertonic saline and reaspiration (PAIR technique). They showed a decrease in cyst size by three months and a marked decrease to 0.5 ml. by 9 months.

Medical management of hydatid cysts and recurrent cysts with Albendazole and Praziquantal has also been tried.21

REFERENCES

1.Del Brutto OH. “Neurocysticercosis: Updating in diagnosis and Treatment” Neurolgia, 2005;20(8):412-8.

2.Del la Garza Y, Graviss E A, Daver NG,Gambarin KJ, Shandera WX, Schanz PM, White AC Jr : “Epidemiology of Neurocysticercosis in Houston, Texas” Am J Trop. Med. Hyg.2005;73(4):766-70.

3.Towas JM, Hoffmann CJ,: “Neurocysticercosis in Oregon: 1995-2000” Emerg. Infect Dis 2004;10(3):508-10.

4.Pushker N, Bajaj MS, Balasubramanya R: “ Disseminated Cysticercosis involving Orbit, brain and sub-cutaneous tissue”J. Infect. 2005;51(5)e245-8.

5.Chadha V, Pandey PK, Chauhan D, Das s: “ Simultaneous intraocular and bilateral extraocular Muscle involvement in a case of disseminated Cysticercosis” Int.Ophthalmol 2006;15.

6.Gulliani BP, Dadeya S, Malik KP, Jain DC : “Bilateral Cysticercosis of optic nerve” J Neurophthalmol 2001;21 (3):217-8.

7.Bajaj MS, pushker N: “Optic nerve cysticercosis” Clinical Experimental Ophthalmol; 2002;30(2);140-3.

8.Sudan R, Muralidhar R, Sharma P, “ Optic Nerve Cysticercosis: case report and review of current management” Orbit, 2005;24(2);159-62.

9.Sekhar GC, Honavar SG, “ Myocysticercosis Experience with imaging and therapy” Ophthalmol, 1999;106(12) 2336-40.

10.Honavar SG, Sekhar CG, “ Ultrasonological Characterestics of Extraocular Cysticercosis” Orbit 1998;17(4),271-84

11.Bansal RK, Gupta A,Grewal SP, Mohan K, “ Spontaneous extrusion of cysticercosis: Report of three cases”, Indian J ophthalmol,1992;40(2):59-60.

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12.Turgut AT, Turgut M, Ko?ar U.: "Hydatidosis of the orbit in Turkey: results from review of the literature 1963-2001" Int Ophthalmol. 2004;25(4):193-200.

13.Xiao A, Xueyi C: "Hydatid cysts of the orbit in Xinjiang: a review of 18 cases", Orbit. 1999;18(3):151-55.

14.Gomez Morales A, Croxatto JO, Crovetto L, Ebner R; Hydatid cysts of the orbit. A review of 35 cases, Ophthalmology. 1988;95(8):1027-32.

15.Kiratli H, Bilgiç S, Oztürkmen C, Aydin O: Intramuscular hydatid cyst of the medial rectus muscle, Am J Ophthalmol. 2003;135(1):98-9.

16.Jhn lCrompton, Prema V Iyer, David J Merry John Tomich, Llance V Perrett "Hydatid cyst: an unusual cause of diplopia" Australian and New Zealand Journal of Ophthalmology 13 (2), 195-203.

17.Rastogi A, Arora R, Chaturvedi K. Orbital hydatid cyst: an unusual presentation", Orbit. 1998;17(2):107-111.

18.Betharia SM, Pushker N, Sharma V, Avinash M, Kashyap S: "Disseminated hydatid disease involving orbit, spleen, lung and liver". Ophthalmologica. 2002;216(4): 300-4.

19.Andronikou S, Welman CJ, Kader E: "Classic and unusual appearances of hydatid disease in children" Pediatr Radiol. 2002;32(11):817-28.

20.Akhan O, Bilgiç S, Akata D, Kiratli H, Ozmen MN:" Percutaneous treatment of an orbital hydatid cyst: a new therapeutic approach" Am J Ophthalmol. 1998;125(6): 877-9.

21.Sihota R, Sharma T:Albendazole therapy for a recurrent orbital hydatid cyst Indian J Ophthalmol. 2000;48(2):142-3.

INTRODUCTION

The surgeon encounters orbital fractures in the acute, subacute and chronic settings. In each situation, the treatment goals are similar-restoration of orbital integrity and volume. However, the nuances of treatment can vary widely according to the specific setting and injury. In this chapter, we will attempt to provide an overview of how we approach orbital fractures in a variety of settings, and provide enough reference materials to satisfy the need for additional study.

ANATOMY

The adult human orbit has a volume of approximately 30 ml, of which the globe accounts for approximately 7 ml, or about 25%.1 It traditionally is said to be formed of 7 bones: maxillary, zygomatic, frontal, lacrimal, ethmoid (lamina papyracea), palatine, and the sphenoid, although the greater and lesser wings of the sphenoid develop independently during embryogenesis [the alisphenoid (greater wing) and orbitosphenoid (lesser wing) bones].2 The optic canal is part of the lesser wing of the sphenoid.

Orbital bony strength is dependent on a series of dense bony buttresses that provide structural integrity and create a protective frame around the eye. Anteriorly are the frontomaxillary and frontozygomatic buttresses. Posteriorly is the pterygomaxillary buttress (Figure 17.1).3-9 Orbital fractures can be classified as blow-out fractures (no rim involvement), and fractures that involve the rim

as part of La Forte II or III fractures. Fractures involving the buttresses typically present with larger displacements. Alternatively, when the buttresses are intact, trapdoor-type fractures are more common.4

The anatomic landmarks of most fractures correlate with the bony anatomy (Figure 17.2). Floor

Figure 17.1: Orbitomaxillary buttresses. Nasomaxillary (medial), zygomaticomaxillary (lateral). Based on Gruss et al., 1986.

Diagrammatic representation of the maxillary buttresses showing the two anterior buttresses (medial or nasomaxillary and lateral or zygomaticomaxillary) and the posterior buttress (pterygomaxillary). The relationship of these buttresses to the cranial base above, the mandible below and the correct occlusion is seen

fractures often extend up to the infraorbital groove and/or canal, since the thin bone of the floor abuts the stronger bone of the canal. Posteriorly, floor fractures nearly always leave the most posterior portion intact since it is part of the large and strong palatine bone. Medially, floor fractures often leave intact the inferomedial strut, a part of the frontomaxillary buttress.10, 11 Medial wall fractures often end at the frontoethmoidal suture line: the lamina papyracea is very thin, whereas the frontal bone is thick and supported by the cribriform plate. Lateral wall fractures often occur as part of a complex fracture involving the zygomatic arch and the maxillary bone.

Orbital nerves and vascular bundles can often be involved in orbital fractures, and serve as important landmarks (Figure 17.2). Since the infraorbital nerve often abuts the floor fracture edge, it is commonly contused by the trauma but rarely severed. Hence, hypoesthesia in the V2 distribution of the trigeminal nerve is very common following orbital trauma, but such numbness typically resolves, at least partially, several weeks to months after injury unless surgical repair causes further damage. Just posterior to where the infraorbital groove and canal meet, a perforating branch of the infraorbital artery is often encountered, which can cause significant

Orbital Fractures 221

bleeding if not isolated and cauterized in the course of surgical repair.12

The zygomatic bone contains foramina for both the zygomaticofacial and the zygomaticotemporal nerves, branches of the V1 division of the trigeminal nerve. Overall, the area innervated by these nerves is small, and patients often tolerate hypoesthesia associated with injury to these nerves, which may occur from surgery as well as from the initial injury.

Injury to the infratrochlear, posterior ethmoidal and/or anterior ethmoidal neurovascular bundles are uncommon, but can be associated with significant bleeding. Superomedial orbital injury may also be associated with damage to the trochlea, causing torsional diplopia.

Orbital fractures can often cause ocular dysmotility. There are several general etiologies in the acute setting: direct muscle damage and/or edema, nerve damage, or muscle entrapment. The restriction caused by muscle entrapment often involves the orbital fibrous connective tissue complex, of which the extraocular muscle pulleys and septa are a part.13,14 Hence, herniation and entrapment of orbital connective tissue that is associated with an extraocular muscle can often cause a clinical picture of entrapment even though the muscle itself is not incarcerated in the fracture. Such findings can often

222 Surgical Atlas of Orbital Diseases

be subtle. So a high index of suspicion is important (Figures 17.3A and B, and 17.4A to D).

Finally, the optic nerve enters the optic canal near the apex of the orbit. Blunt trauma can result in optic nerve injury through several mechanisms: collapse of the optic canal with crush injury to the nerve, injury of perforating vessels to the optic nerve, hemorrhage with compressive optic neuropathy, severing through avulsion of the nerve, and direct injury to the globe with transmission of the impact posteriorly (Figures 17.5 and 17.6).

EXAMINATION

A patient with orbital trauma requires a complete history and ophthalmic examination, including a dilated fundus examination. Any loss of consciousness should be documented, and the possibility of an intraocular or intraorbital foreign body must be addressed. The possibility of an open globe should be considered in every patient with orbital trauma, and an open globe must be ruled out prior to any orbital evaluation and management. Loss of vision, dysmotility, hyphema, and 360° subconjunctival hemorrhage are often associated with a ruptured globe.

When the examination occurs in an intensive care setting, as is often the case, exact history and a full examination cannot be obtained. In such a setting, early evaluation of the pupils, prior to sedation/ analgesia-related miosis, is critical to identifying optic nerve trauma and a relative afferent pupillary defect (RAPD). Intraocular pressure should be measured with a handheld device, such as a Tonopen (Medtronic Ophthalmics, Minneapolis, MN, USA),

and high intraocular pressure treated aggressively. In an alert patient with loss of vision and elevated intraocular pressure, the possibility of a retrobulbar hemorrhage must be assessed, and when appropriate, a lateral canthotomy with cantholysis performed acutely. Particular attention must be given to patients who are on blood-thinning medications, such as warfarin, which can make an orbital hemorrhage both more likely and more severe. Canthotomy incision is a simple and fairly benign technique for rapidly reducing vision-threatening orbital pressure, and the addition of a cantholysis can further improve the decompression.15 It is not rare for patients with an orbital compartment syndrome to report improvement in vision within minutes of a canthotomy and cantholysis. Evacuation of an orbital hematoma in the acute setting has been described, including a minimally invasive technique.16

While extraocular motility cannot be evaluated in the sedated patient, radiologic suggestion of entrapment should be further investigated with forced duction testing at the bedside, which the sedation facilitates (Figures 17.7A to E). It should be

A

Figures 17.3A and B: Mild muscle entrapment. Patient is a 45 years old man who suffered a left blow-out fracture and experienced diplopia in upgaze. He presented several weeks after his initial trauma with a CT scan taken shortly after the injury. Examination found mild restriction of the left eye in upgaze. The CT scan showed left inferior rectus rounding, consistent with muscle entrapment. He was only minimally symptomatic in upgaze with no diplopia in primary or downgaze, and did not require surgical repair

B