Orbital Diseases Practice Questions

Q: An orbital fracture caused by a ping pong ball is:

Blow out fracture. ***Blow out fracture*** - A **blow-out fracture** occurs when an object, like a ping pong ball, impacts the orbital rim and compresses the globe, causing a sudden increase in intraorbital pressure. - This pressure then fractures the weakest parts of the orbit, typically the **orbital floor** (into the maxillary sinus) or the **medial wall** (into the ethmoid sinus), while sparing the orbital rim. *Blow in fracture* - A **blow-in fracture** involves a direct impact to the orbital rim, causing the rim bones to be pushed inward. - This type of fracture often results from a **smaller, high-velocity object** directly hitting the bone and forcing the orbital contents inward. *Orbital fracture* - **Orbital fracture** is a general term that encompasses any break in the bones surrounding the eye socket. - While a blow-out fracture is a type of orbital fracture, this option is too broad and does not specifically describe the mechanism of injury by a ping pong ball. *Compound fracture* - A **compound fracture** (also known as an open fracture) is one where the broken bone penetrates the skin, creating an open wound. - This term describes the **integrity of the skin** around the fracture, not the mechanism of the orbital injury.

Q: Blowout fracture of the orbit is characterized by all, except

Exophthalmos. ***Exophthalmos*** - **Exophthalmos** (protrusion of the eyeball) occurs when there is an increase in orbital contents, such as from a tumor or edema behind the globe. - In a **blowout fracture**, the orbital contents herniate into the adjacent sinus, leading to an increase in orbital volume, which typically causes **enophthalmos** (recession of the eyeball), not exophthalmos, as the globe sinks into the enlarged bony cavity. *Tear drop sign* - The **tear drop sign** is a classic radiological finding on sinus X-rays or CT scans in blowout fractures. - It represents the **herniated orbital tissue** (fat and/or muscle) projecting into the maxillary sinus, resembling a teardrop. *Diplopia* - **Diplopia** (double vision) is a common symptom of blowout fractures, especially on upward or downward gaze. - It results from the **entrapment** of an extraocular muscle (most commonly the inferior rectus) in the fractured bone, limiting its movement. *Forced duction test* - The **forced duction test** is a clinical maneuver used to assess the presence of mechanical restriction of eye movement. - A positive forced duction test, indicating mechanical restriction due to muscle entrapment, is a characteristic finding in blowout fractures and helps differentiate it from nerve palsies.

Q: Enophthalmos is caused by fracture of:

Floor of orbit. ***Floor of orbit*** - A fracture of the orbital floor allows orbital contents, such as fat and extraocular muscles, to **herniate into the maxillary sinus**, leading to a decrease in orbital volume and thus **enophthalmos**. - This type of fracture is also known as a **blow-out fracture** and can entrap the inferior rectus muscle, causing **diplopia** on upward gaze. *Lateral wall of orbit* - Fractures of the lateral wall of the orbit (involving the **zygoma** or **sphenoid bone**) are less common and typically result in **proptosis** if the orbital volume increases due to hemorrhage, or no significant change in eye position. - While they can be associated with other facial bone injuries, they do not directly cause enophthalmos by way of volume reduction into an adjacent sinus. *Medial wall of orbit* - Fractures of the medial wall, involving the **ethmoid air cells**, can also lead to herniation of orbital contents, potentially causing **enophthalmos**. - However, the orbital **floor** is more commonly fractured in blow-out injuries that specifically lead to significant enophthalmos due to its relative weakness. *Roof of orbit* - Fractures of the orbital roof typically involve the **frontal bone** and are often associated with **intracranial injuries** or **pneumocephalus**. - While they can cause orbital edema or hemorrhage, they usually do not result in enophthalmos; instead, they might cause **proptosis** or a visible deformity.

Q: Blow out fracture of orbit commonly involves:-

Floor is involved first. ***Floor is involved first*** - The **orbital floor** (composed mainly of the maxillary bone and portions of the palatine and zygomatic bones) is the most common site for a **blowout fracture** due to its relative weakness. - Trauma to the globe increases **intraorbital pressure**, causing the weakest part of the orbit, which is commonly the floor, to fracture and displace fragments into the maxillary sinus. *Medial wall is involved first as it is the thinnest* - While the **medial wall** (primarily the lacrimal bone and the lamina papyracea of the ethmoid bone) is indeed the **thinnest** portion of the orbit, it is structurally supported by the ethmoid air cells, making it less prone to fracture from direct globe impact compared to the floor. - Fractures of the medial wall can occur but are less common as the primary site of injury than the orbital floor. *The patient is not able to look up due to inferior rectus entrapment* - While **inferior rectus muscle** entrapment in orbital floor fractures does cause restricted upward gaze, this is a **complication** of the fracture, not what the fracture "commonly involves" anatomically. - The question asks which **anatomical structure** is commonly involved, not the clinical presentation. - Inferior rectus entrapment occurs in blowout fractures but doesn't answer which orbital wall is most commonly fractured. *Roof is involved first as it bears the maximum impact* - The **orbital roof** (formed by the frontal bone) is the strongest part of the orbit and rarely fractures from globe impact alone; it typically requires high-energy trauma to the forehead. - If the roof were involved, it would likely be due to direct impact to the supraorbital region, not from compression of the globe which usually affects the floor or medial wall.

Q: Most common cause of fracture of roof of orbit?

Blow on the forehead. ***Blow on the forehead*** - A direct impact to the forehead transmits force **posteriorly and inferiorly**, directly affecting the thin and fragile **roof of the orbit**. - The roof of the orbit, being part of the **frontal bone**, is susceptible to fracture from such anterior blunt trauma. *Blow on back of head* - A blow to the back of the head primarily impacts the **occipital bone** and associated structures. - The force from this type of impact is unlikely to directly fracture the orbital roof, which is located anteriorly, and would more likely result in **posterior fossa** or **base of skull** fractures. *Blow on the upper jaw* - An impact to the upper jaw typically results in fractures of the **maxilla** or **zygoma**, such as **Le Fort fractures**. - This type of trauma has a different vector of force that generally does not directly cause fractures of the orbital roof. *Blow on parietal bone* - A blow to the parietal bone typically leads to fractures of the **calvarium** in that region. - The force is distributed across the top or side of the skull and usually does not directly propagate to cause isolated fractures of the orbital roof.

Q: Enophthalmos can be caused by all of the following EXCEPT:

Horner's syndrome. ***Horner's syndrome*** - **Horner's syndrome** is characterized by **ptosis**, **miosis**, and **anhidrosis** on the affected side. - While it can manifest with a mild degree of **apparent enophthalmos**, this is primarily due to the **ptosis creating an illusion** of globe retraction and **not true enophthalmos**. - It is caused by disruption of the **sympathetic nervous supply**, not by actual posterior displacement of the globe. *Cicatricial changes* - **Cicatricial changes** (scarring) within the orbit can cause **traction on the globe**, pulling it inward and resulting in **true enophthalmos**. - This scarring can occur following **trauma**, **inflammation**, or **surgery** affecting the orbital tissues. *Orbital floor fracture* - An **orbital floor fracture** typically leads to **enophthalmos** due to **herniation of orbital contents** (fat, muscle) into the maxillary sinus. - This involves a **structural defect** with increased orbital volume and loss of support for the globe. *Loss of orbital fat* - **Loss of orbital fat**, often seen in conditions like **Romberg's disease**, severe dehydration, or aging, causes the globe to sink backward. - This is due to a **reduction in volume supporting the globe**, resulting in **true enophthalmos**.

Q: A man presents 6 hrs after head injury complaining of mild proptosis and scleral hyperemia:

Retro-orbital hematoma. ***Retro-orbital hematoma*** - The sudden onset of **proptosis** and **scleral hyperemia** within hours of a head injury is highly suggestive of bleeding behind the eye. - A **retro-orbital hematoma** causes increased orbital pressure, leading to the forward displacement of the eyeball (proptosis) and conjunctival injection (scleral hyperemia). *Caroticocavernous fistula* - This condition involves an abnormal communication between the carotid artery and the cavernous sinus, typically presenting with a **pulsatile proptosis** and a **bruit** over the eye. - While it can cause proptosis and hyperemia, its onset is usually not as acute as 6 hours post-trauma without being a direct major vessel injury in a recent trauma. *Pneumo-orbit* - A pneumo-orbit involves **air entering the orbit**, often following trauma that fractures an orbital wall communicating with a paranasal sinus. - Symptoms include **periorbital crepitus** and exophthalmos, but scleral hyperemia is not a primary or dominant feature. *Orbital cellulitis* - Orbital cellulitis is an **infection of the orbital tissues**, usually presenting with proptosis, ophthalmoplegia, pain, and fever. - This is an infectious process and would typically take longer than 6 hours to develop to such an extent after an acute trauma without an open wound or obvious contamination.

Q: A young adult presents 2 days after trauma to the eye with proptosis and pain in the right eye. On examination, he is found to have a bruise on the right eye and forehead. The most likely diagnosis is:

Carotico-cavernous fistula. ***Carotico-cavernous fistula*** - The presentation of **proptosis**, **pain**, and a **bruise on the eye and forehead** following trauma is highly suggestive of a carotico-cavernous fistula. - This condition involves an abnormal connection between the **carotid artery** and the **cavernous sinus**, often resulting from trauma, leading to increased venous pressure and orbital congestion. *Cavernous sinus thrombosis* - This condition is typically associated with **infection** spreading from the face or sinuses, rather than direct trauma. - While it can cause proptosis and pain, the presence of a distinct bruise and forehead involvement post-trauma points away from an infectious etiology. *Internal carotid artery aneurysm* - An aneurysm itself usually does not immediately present with **proptosis** and **ecchymosis** unless it has ruptured or is causing direct compression. - While an aneurysmal rupture could cause hemorrhage, the specific cluster of symptoms post-trauma strongly favors a vascular shunting issue. *Fracture sphenoid bone* - A sphenoid bone fracture can occur with head trauma, but it would typically present with symptoms such as **cranial nerve deficits** (especially optic nerve or oculomotor nerve dysfunction), **CSF leak**, or **hemorrhage** into surrounding structures. - While a fracture could indirectly contribute to other issues, it doesn't directly explain the combination of proptosis, pain, and orbital bruising as a primary diagnosis in this context.

Q: In blowout fractures, which of the following is seen?

Enophthalmos. ***Enophthalmos*** - A **blowout fracture** of the orbit typically involves the orbital floor or medial wall from direct trauma to the eye or periorbital region. - The fracture allows orbital contents (fat and muscle) to herniate into the maxillary sinus or ethmoid sinuses, **increasing orbital volume**. - This increased volume causes the eye to recede backward into the orbit, resulting in **enophthalmos** (sunken eye appearance). - **Key clinical features**: enophthalmos, diplopia (due to inferior rectus/medial rectus entrapment), restricted eye movements, infraorbital nerve hypoesthesia. *Exophthalmos* - **Exophthalmos** (proptosis) is forward protrusion of the eye, occurring when orbital volume is **decreased** or orbital contents are **increased** (e.g., thyroid eye disease, orbital tumors, orbital hemorrhage). - This is the **opposite** of enophthalmos and would not occur in a blowout fracture where orbital volume increases. *Bulbar hemorrhage* - **Subconjunctival hemorrhage** may occur as an associated finding from ocular trauma but is not a characteristic or defining feature of blowout fractures. - Many types of blunt ocular trauma can cause conjunctival hemorrhage without orbital fracture. *None of the options* - Incorrect because **enophthalmos** is the classic and characteristic finding of orbital blowout fractures.

Question 1

An orbital fracture caused by a ping pong ball is:

Accepted Answer

Blow out fracture

Answer

Blow in fracture

Answer

Orbital fracture

Answer

Compound fracture

Question 2

Blowout fracture of the orbit is characterized by all, except

Accepted Answer

Exophthalmos

Answer

Tear drop sign

Answer

Diplopia

Answer

Forced duction test

Question 3

Enophthalmos is caused by fracture of:

Accepted Answer

Floor of orbit

Answer

Lateral wall of orbit

Answer

Medial wall of orbit

Answer

Roof of orbit

Question 4

Blow out fracture of orbit commonly involves:-

Accepted Answer

Floor is involved first

Answer

Medial wall is involved first as it is the thinnest

Answer

Roof is involved first as it bears the maximum impact

Answer

The patient is not able to look up due to inferior rectus entrapment

Question 5

Most common cause of fracture of roof of orbit?

Accepted Answer

Blow on the forehead

Answer

Blow on back of head

Answer

Blow on the upper jaw

Answer

Blow on parietal bone

Question 6

Enophthalmos can be caused by all of the following EXCEPT:

Accepted Answer

Horner's syndrome

Answer

Orbital floor fracture

Answer

Loss of orbital fat

Answer

Cicatricial changes

Question 7

A man presents 6 hrs after head injury complaining of mild proptosis and scleral hyperemia:

Accepted Answer

Retro-orbital hematoma

Answer

Caroticocavernous fistula

Answer

Pneumo-orbit

Answer

Orbital cellulitis

Question 8

A young adult presents 2 days after trauma to the eye with proptosis and pain in the right eye. On examination, he is found to have a bruise on the right eye and forehead. The most likely diagnosis is:

Accepted Answer

Carotico-cavernous fistula

Answer

Cavernous sinus thrombosis

Answer

Internal carotid artery aneurysm

Answer

Fracture sphenoid bone

Question 9

In blowout fractures, which of the following is seen?

Accepted Answer

Enophthalmos

Answer

Bulbar hemorrhage

Answer

None of the options

Answer

Exophthalmos

Question 10

Which of the following statements about thyroid eye disease is false?

Accepted Answer

The management corresponds to improvement in thyrotoxic state

Answer

NOSPECS score is used to classify thyroid eye disease

Answer

Can lead to visual loss

Answer

Seen in more than 10% of patients with hyperthyroidism

Orbital Diseases — MCQs

Orbital Diseases — MCQs

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