Orbital Trauma — MCQs
Patient with history of blunt trauma to face presents with enophthalmos, diplopia on upward gaze and loss of sensitivity over cheek. True statement about this is:
Which of the following is NOT a characteristic of a blowout fracture of the orbit?
During a baseball game, the pitcher is hit in the left eye with a hard-hit line drive. He is rushed to the nearest emergency department where CT scan reveals left orbital rim and floor fractures and fluid in the left maxillary sinus. What are physical findings likely to include?
Blowout fracture of the orbit is characterized by all, except
Following blunt trauma a young male presents with a D shaped pupil. What is the diagnosis?
In blowout fractures, which of the following is seen?
Diameter of the Vossius's ring is
A patient presented with a history of diplopia and restricted eye movements. What is the most likely diagnosis based on the clinical and CT images?
Orbital blow-out fracture involves:
Blow out fracture of orbit commonly involves:-
Orbital Trauma Indian Medical PG Practice Questions and MCQs
Question 1: Patient with history of blunt trauma to face presents with enophthalmos, diplopia on upward gaze and loss of sensitivity over cheek. True statement about this is:
- A. Maxillary fracture
- B. Zygomatic bone is most likely injured
- C. It is a blow out fracture (Correct Answer)
- D. Frontal bone fracture
Explanation: ***It is a blow out fracture*** - The combination of **enophthalmos** (sunken eye), **diplopia on upward gaze** (due to **inferior rectus muscle entrapment**), and **loss of sensitivity over the cheek** (indicating infraorbital nerve involvement) are classic signs of an **orbital blowout fracture**. - These fractures typically involve the **orbital floor** or medial wall, caused by a direct impact to the orbit, which transmits force to the thin bony walls causing them to fracture while the orbital rim remains intact. *Maxillary fracture* - While the **infraorbital nerve** passes through the maxilla, a general maxillary fracture typically presents with broader symptoms such as **midfacial pain**, **swelling**, and **malocclusion**, which are not specified here. - Maxillary fractures often involve the **zygomaticomaxillary complex** or Le Fort patterns, which usually lead to more extensive facial abnormalities. *Zygomatic bone is most likely injured* - A **zygomatic arch fracture** would primarily cause **flattening of the cheek** and pain upon opening the mouth, not enophthalmos or diplopia on upward gaze. - While the zygoma forms part of the orbit, isolated zygomatic fractures rarely cause these specific orbital findings. *Frontal bone fracture* - **Frontal bone fractures** typically result from **high-impact trauma** and can involve the **frontal sinus**, leading to **forehead swelling**, **CSF rhinorrhea**, or **periorbital ecchymosis** (raccoon eyes). - The symptoms described are not characteristic of a frontal bone fracture.
Question 2: Which of the following is NOT a characteristic of a blowout fracture of the orbit?
- A. Orbital floor and medial wall involvement are common
- B. Exophthalmos (Correct Answer)
- C. Tear drop sign on CT scan
- D. Diplopia due to muscle entrapment
Explanation: ***Exophthalmos*** - A **blowout fracture** typically causes the orbital contents to herniate into adjacent sinuses (maxillary or ethmoid), leading to an **increase in orbital volume**. - This increased orbital volume, combined with swelling and potential hemorrhage, usually results in **enophthalmos** (recession of the eyeball), not exophthalmos (protrusion of the eyeball). *Orbital floor and medial wall involvement are common* - The **orbital floor** (paper-thin bone separating the orbit from the maxillary sinus) and **medial wall** (separating the orbit from the ethmoid sinus) are the weakest structures of the orbit and are most commonly fractured in a blowout injury. - These areas are susceptible to fracture due to the force transmitted to the orbital contents, causing a sudden increase in intraorbital pressure. *Tear drop sign on CT scan* - The **tear drop sign** on a CT scan is a classic finding in orbital blowout fractures, representing the **herniation of orbital fat** or inferior rectus muscle into the maxillary sinus. - This sign indicates the displacement of soft tissue through the fractured orbital floor. *Diplopia due to muscle entrapment* - **Diplopia** (double vision) is a common symptom in blowout fractures, often caused by the **entrapment of extraocular muscles** (most commonly the inferior rectus or medial rectus) within the fracture site. - Muscle entrapment restricts ocular motility, particularly on upward or sideways gaze, leading to double vision.
Question 3: During a baseball game, the pitcher is hit in the left eye with a hard-hit line drive. He is rushed to the nearest emergency department where CT scan reveals left orbital rim and floor fractures and fluid in the left maxillary sinus. What are physical findings likely to include?
- A. Exophthalmos
- B. Cheek numbness (Correct Answer)
- C. Lateral diplopia
- D. Epistaxis
Explanation: ***Cheek numbness*** - **Orbital floor fractures** commonly damage the **infraorbital nerve**, which runs through the **infraorbital canal** in the orbital floor. - The infraorbital nerve provides sensation to the **lower eyelid, upper cheek, lateral nose, upper lip, and upper gingiva**. - **Cheek numbness (infraorbital nerve paresthesia) is the MOST COMMON physical finding** in orbital floor fractures, occurring in up to 80% of cases. - This is a classic exam finding and key diagnostic feature. *Epistaxis* - While theoretically possible if there's communication between the orbit and nasal cavity, **epistaxis is NOT a common or characteristic finding** in isolated orbital floor fractures. - Would require significant displacement with direct nasal involvement or fracture extension into the nasal bones. - The fluid in the maxillary sinus on CT represents blood/edema, not necessarily active nasal bleeding. *Exophthalmos* - This term means **protrusion of the eyeball** forward from the orbit. - Orbital floor fractures cause the OPPOSITE finding: **enophthalmos** (recession of the eyeball backward). - This occurs due to herniation of orbital contents (fat, muscles) into the enlarged orbital cavity (maxillary sinus). *Lateral diplopia* - **Lateral diplopia** (horizontal double vision) results from dysfunction of the **medial or lateral rectus muscles** (or their nerves). - Orbital floor fractures characteristically cause **VERTICAL diplopia** due to entrapment or contusion of the **inferior rectus muscle** or **inferior oblique muscle**. - Patients have double vision when looking up or down, not side to side.
Question 4: Blowout fracture of the orbit is characterized by all, except
- A. Exophthalmos (Correct Answer)
- B. Tear drop sign
- C. Diplopia
- D. Forced duction test
Explanation: ***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.
Question 5: Following blunt trauma a young male presents with a D shaped pupil. What is the diagnosis?
- A. Iridodialysis (Correct Answer)
- B. Orbital fracture
- C. Traumatic hyphema
- D. Iridoschisis
Explanation: ***Iridodialysis*** - A **D-shaped pupil** strongly suggests **iridodialysis**, which is a disinsertion of the iris root from the ciliary body. - This typically occurs after **blunt trauma** to the eye, allowing the pupil to be distorted towards the point of detachment. *Orbital fracture* - An orbital fracture often presents with **periorbital ecchymosis**, **diplopia**, **enophthalmos**, or **proptosis**, depending on the fracture location. - While it results from blunt trauma, it doesn't directly cause a D-shaped pupil but can lead to other ocular complications. *Traumatic hyphema* - Traumatic hyphema is characterized by **blood in the anterior chamber** of the eye, which can be visible as a red fluid level. - While caused by blunt trauma, it typically presents with blurred vision and pain, not a D-shaped pupil. *Iridoschisis* - Iridoschisis is a rare condition involving the **splitting of the iris stroma**, usually in the elderly, and is not typically associated with acute trauma or a D-shaped pupil. - It often leads to **fine, detached iris fibers** floating in the anterior chamber, rather than a gross deformation of the pupil.
Question 6: In blowout fractures, which of the following is seen?
- A. Bulbar hemorrhage
- B. None of the options
- C. Enophthalmos (Correct Answer)
- D. Exophthalmos
Explanation: ***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 7: Diameter of the Vossius's ring is
- A. Equal to normal pupil
- B. Smaller than the normal pupil (Correct Answer)
- C. Much larger than the normal pupil
- D. Slightly larger than the normal pupil
Explanation: ***Smaller than the normal pupil*** - The **Vossius's ring** is a deposition of pigment on the anterior lens capsule, formed by contact with the iris during trauma. - Due to the **constriction of the pupil** at the time of impact, the imprinting tends to be *smaller* than the resting pupil size. *Equal to normal pupil* - This is incorrect because the ring represents the imprint of the **pupillary margin** against the lens during a moment of **miosis (pupil constriction)** following trauma, not the normal resting pupil size. - The transient nature of the trauma-induced miosis means the imprinted diameter will be less than the typical **resting/normal pupil diameter**. *Much larger than the normal pupil* - This is incorrect because trauma usually causes **pupillary spasm and miosis**, which would result in a *smaller* imprint, not a larger one. - A larger imprint would imply a **dilated pupil** at the time of impact, which is contrary to the typical physiological response. *Slightly larger than the normal pupil* - This is incorrect as the trauma-induced **miosis** would make the imprint *smaller* than the normal pupil, not larger. - Even a slight increase in size would contradict the mechanism of formation, which involves temporary **pupillary constriction**.
Question 8: A patient presented with a history of diplopia and restricted eye movements. What is the most likely diagnosis based on the clinical and CT images?
- A. Le Fort fracture
- B. Maxillary fracture
- C. Zygomatic fracture
- D. Blowout fracture (Correct Answer)
Explanation: ***Blowout fracture*** - The CT image shows a **fracture of the orbital floor**, with associated **herniation of orbital contents** (fat and inferior rectus muscle) into the maxillary sinus. - This type of fracture commonly causes **diplopia** (due to muscle entrapment) and **restricted eye movements**. *Le Fort fracture* - Le Fort fractures involve the **midface and maxilla** as a whole, typically causing widespread facial instability. - They are classified into three types (I, II, III), none of which are exclusively characterized by an isolated orbital floor fracture with muscle entrapment. *Maxillary fracture* - While an orbital floor fracture involves the maxilla, a "maxillary fracture" is a broad term and does not specifically describe the characteristic features of **orbital content prolapse** and their resulting symptoms. - Isolated maxillary fractures might not cause diplopia or restricted eye movements unless they directly involve the orbit. *Zygomatic fracture* - A zygomatic fracture (either isolated or as part of a zygomaticomaxillary complex fracture) primarily affects the **cheekbone**. - While it can involve the orbital rim, it typically presents with **facial asymmetry**, **numbness** in the infraorbital nerve distribution, and sometimes **trismus**, rather than isolated muscle entrapment causing diplopia, as seen in the image.
Question 9: Orbital blow-out fracture involves:
- A. Lateral wall and roof of orbit
- B. Medial wall and floor of orbit (Correct Answer)
- C. Medial wall and roof of orbit
- D. Lateral wall and floor of orbit
Explanation: Medial wall and floor of orbit - An orbital blow-out fracture typically involves the **medial wall** (lamina papyracea of the ethmoid bone) and the **floor** (maxillary bone) of the orbit because these are the weakest bony structures. - The force of impact on the globe is transmitted to the orbital walls, causing them to fracture outwards into the adjacent sinuses. *Lateral wall and roof of orbit* - The **lateral wall** (zygomatic bone) and **roof** (frontal bone) of the orbit are structurally strong and less commonly involved in isolated blow-out fractures. - Fractures in these areas typically result from high-impact trauma and are often associated with other facial bone injuries. *Medial wall and roof of orbit* - While the **medial wall** is frequently involved, the **roof** of the orbit is a thick, sturdy bone and is less susceptible to blow-out forces. - Fractures of the orbital roof usually occur due to direct impact or high-energy trauma to the forehead. *Lateral wall and floor of orbit* - Although the **floor** is commonly fractured, the **lateral wall** is a robust structure and is not typically involved in isolated blow-out fractures. - Combined fractures of the lateral wall and floor would indicate a more extensive orbital impact, often with other mid-facial trauma.
Question 10: Blow out fracture of orbit commonly involves:-
- A. Medial wall is involved first as it is the thinnest
- B. Floor is involved first (Correct Answer)
- C. Roof is involved first as it bears the maximum impact
- D. The patient is not able to look up due to inferior rectus entrapment
Explanation: ***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.
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