A 24-year-old girl with a history of head trauma presented with multiple lacerations on the face and eyelids and a base of skull fracture. It was noticed she wasn't able to pass tears. The probable cause is injury to-
Q162
The commonest cause of vitreous hemorrhage in young adults is:
Q163
Hyphaema, or blood in the anterior chamber, is suggestive of:
Q164
The most toxic intraocular foreign body is a particle of:
Ocular Trauma Indian Medical PG Practice Questions and MCQs
Question 161: A 24-year-old girl with a history of head trauma presented with multiple lacerations on the face and eyelids and a base of skull fracture. It was noticed she wasn't able to pass tears. The probable cause is injury to-
A. Lacrimal Gland
B. Superior Canaliculus
C. Upper eyelid
D. Inferior Canaliculus (Correct Answer)
Explanation: ***Inferior Canaliculus***
- The **inferior canaliculus** is a common site of injury given its anatomical position and the common mechanisms of trauma to the eyelids. Obstruction or laceration of this structure can prevent tears from draining into the nasolacrimal sac, leading to **epiphora** (overflowing tears).
- Given the patient's **multiple lacerations on the eyelids** and inability to pass tears, injury to the drainage system, specifically the inferior canaliculus, is the most probable cause.
*Lacrimal Gland*
- The **lacrimal gland** is responsible for producing tears. An injury to the lacrimal gland would typically result in a **decrease in tear production**, rather than an inability to pass existing tears.
- While head trauma can affect the lacrimal gland, the symptom of "not able to pass tears" specifically points to a problem with the **tear drainage system**.
*Superior Canaliculus*
- The **superior canaliculus** also plays a role in tear drainage, but it contributes less significantly than the inferior canaliculus, especially in maintaining basal tear drainage.
- While injury to the superior canaliculus can impair tear drainage, the **inferior canaliculus** is typically the primary route and its obstruction would more readily result in noticeable issues with tear passage.
*Upper eyelid*
- Lacerations to the **upper eyelid** itself, without affecting the lacrimal drainage structures, would primarily cause cosmetic deformities, swelling, or visual obstruction.
- An isolated injury to the upper eyelid generally would not prevent the passage of tears unless it directly involved the lacrimal gland's ducts (unlikely) or caused severe swelling that secondarily obstructed the drainage system.
Question 162: The commonest cause of vitreous hemorrhage in young adults is:
A. Hypertension
B. Lens extraction
C. Diabetes
D. Trauma (Correct Answer)
Explanation: ***Trauma***
- **Ocular trauma** is the **leading cause of vitreous hemorrhage in young adults** (age <40 years), directly damaging retinal blood vessels or causing retinal tears resulting in bleeding into the vitreous.
- This can include blunt or penetrating injuries, leading to the sudden onset of **decreased vision** and **floaters**.
- In younger populations, trauma accounts for the majority of vitreous hemorrhage cases.
*Diabetes*
- **Diabetic retinopathy**, characterized by fragile new blood vessels (**neovascularization**), is the **commonest cause overall in older populations** and across all age groups combined.
- These abnormal vessels (proliferative diabetic retinopathy) can rupture easily, particularly with sudden increases in intraocular pressure, Valsalva maneuvers, or during sleep.
- However, in young adults specifically, trauma surpasses diabetes as the primary etiology.
*Hypertension*
- While **severe hypertension** can lead to retinal hemorrhages, it is a less common direct cause of vitreous hemorrhage compared to other etiologies.
- Hypertensive retinopathy primarily affects the retinal vessels, which less frequently rupture into the vitreous cavity.
*Lens extraction*
- Complications from **cataract surgery** (lens extraction) can sometimes include vitreous hemorrhage, but this is a relatively rare occurrence.
- It's typically due to iatrogenic damage to retinal vessels during the surgical procedure or rupture of pre-existing **fragile neovascular vessels** in patients with uncontrolled diabetes.
Question 163: Hyphaema, or blood in the anterior chamber, is suggestive of:
A. Intraocular trauma (Correct Answer)
B. Posterior uveitis
C. Capillary hemangioma of the lid
D. High grade myopia
Explanation: ***Intraocular trauma***
- **Hyphaema**, or blood in the **anterior chamber**, is a classic sign of **intraocular trauma**, where eye structures are damaged, leading to bleeding.
- This can result from blunt force or penetrating injuries that rupture blood vessels within the **iris, ciliary body**, or other anterior segment structures.
*Posterior uveitis*
- Posterior uveitis involves inflammation of the **choroid and retina**, not typically causing bleeding into the **anterior chamber**.
- It presents with symptoms like **floaters** and **decreased vision**, without direct hyphaema.
*Capillary hemangioma of the lid*
- A capillary hemangioma is a **benign vascular tumor** on the eyelid and does not cause **intraocular bleeding** into the anterior chamber.
- While it can disrupt vision by blocking the visual axis, it is an **external lesion**.
*High grade myopia*
- High grade myopia leads to a **stretched globe** and **retinal thinning**, increasing the risk of **retinal detachment** or **macular degeneration**.
- It does not directly cause **hyphaema**, which is an anterior chamber bleeding event.
Question 164: The most toxic intraocular foreign body is a particle of:
A. Copper (Correct Answer)
B. Iron
C. Tantalum
D. Aluminium
Explanation: ***Copper***
- **Copper** is considered the most toxic intraocular foreign body due to its rapid and severe inflammatory reaction, leading to **chalcosis oculi**.
- This reaction can cause significant damage to ocular structures, such as the retina and optic nerve, resulting in **vision loss**.
*Iron*
- **Iron** foreign bodies cause **siderosis oculi**, a slower but progressive degeneration of ocular tissues due to iron deposition.
- While damaging, **siderosis** is generally less acutely destructive than chalcosis oculi caused by copper.
*Tantalum*
- **Tantalum** is a relatively **inert** material and generally causes minimal to no inflammatory reaction when retained intraocularly.
- It is often used in medical implants due to its **biocompatibility**.
*Aluminium*
- **Aluminium** is largely considered an **inert** intraocular foreign body, similar to tantalum.
- It typically causes little to no inflammatory response and is less likely to lead to significant ocular damage.
