Ocular Trauma — MCQs

Ocular Trauma Indian Medical PG Practice Questions and MCQs

Question 131: Which of the following intraocular foreign bodies causes severe toxicity and needs to be removed promptly?

A. Aluminium
B. Copper (Correct Answer)
C. Chromium
D. Nickel

Explanation: ***Copper*** - **Copper foreign bodies** cause **chalcosis bulbi**, a severe toxic reaction characterized by: - **Greenish discoloration** of anterior lens capsule and cornea - **Retinal degeneration** and pigmentary changes - **Vision loss** if not removed promptly - **Pure copper is highly toxic** and mandates immediate surgical removal to prevent irreversible ocular damage *Aluminium* - **Aluminum foreign bodies** are **inert** and well-tolerated in the eye - Generally do not cause significant inflammatory reactions or toxicity - Removal not required unless causing mechanical complications *Chromium* - **Chromium foreign bodies** are **inert** and non-toxic - Do not cause significant inflammation or tissue damage - Removal typically not necessary unless mechanically disruptive *Nickel* - **Nickel foreign bodies** are **relatively inert** within the eye - Rarely cause toxic reactions or significant inflammation - Removal usually not required unless causing mechanical irritation

Question 132: Most common cause of hyphema due to Blunt trauma

A. Conjunctival vessels
B. Minor arterial circle
C. Choroidal veins
D. Major arterial circle (Correct Answer)

Explanation: ***Major arterial circle*** - The **major arterial circle** of the iris is formed by anastomoses of the long posterior ciliary arteries and anterior ciliary arteries. - This vascular structure is located at the **iris root**, a vulnerable area prone to tearing and hemorrhage upon blunt trauma. *Conjunctival vessels* - Conjunctival vessels are located on the surface of the eye and, while they can bleed (causing a **subconjunctival hemorrhage**), this blood remains superficial and does not enter the anterior chamber to cause hyphema. - Subconjunctival hemorrhage presents as a distinct red patch on the sclera, unlike the layering of blood in the anterior chamber seen in hyphema. *Minor arterial circle* - The minor arterial circle is located within the iris stroma, closer to the pupillary margin, and is less robust than the major arterial circle. - While it can contribute to bleeding, it is less commonly the primary source of significant hyphema following blunt trauma compared to the larger vessels at the iris root. *Choroidal veins* - Choroidal veins are located in the choroid layer, posterior to the retina, and are not directly involved in anterior chamber hemorrhage. - Bleeding from the choroid typically results in **suprachoroidal hemorrhage** or retinal detachment, not hyphema in the anterior chamber.

Question 133: Most serious injury to the eye is caused by:

A. Nitric acid
B. Hydrochloric acid
C. Lime (Correct Answer)
D. Sulphuric acid

Explanation: ***Lime*** - **Lime (calcium hydroxide)** is an **alkali** that causes **liquefactive necrosis** of ocular tissues, leading to deep penetration and severe, progressive damage. - Alkaline burns saponify cell membranes, resulting in continuous tissue destruction and potentially **corneal opacification**, **limbal ischemia**, and **perforation**. *Nitric acid* - **Nitric acid** is a strong acid that causes **coagulation necrosis**, which tends to create a protective barrier on the tissue. - While serious, this barrier often limits deeper penetration and tissue destruction compared to alkalis. *Hydrochloric acid* - **Hydrochloric acid** is also a strong acid and causes **coagulation necrosis**, similar to nitric acid. - This type of injury typically results in superficial damage to the eye, as the denatured proteins form a physical barrier. *Sulphuric acid* - **Sulphuric acid**, another strong acid, also primarily causes **coagulation necrosis**. - Although it can dehydrate tissues and cause significant superficial damage, its effect is generally less severe and penetrating than strong alkalis.

Question 134: Four months after a blast injury, a middle aged man developed siderosis bulbi. It is due to:

A. Gold
B. Copper
C. Selenium
D. Iron (Correct Answer)

Explanation: ***Iron*** - **Siderosis bulbi** is caused by the deposition of **iron** within the ocular tissues, often resulting from a retained **iron-containing intraocular foreign body**. - The iron ions leak from the foreign body, causing damage to the retina, iris, and lens, eventually leading to vision loss and potentially glaucoma. *Gold* - **Gold** deposition in ocular tissues is known as **chrysiasis**, typically seen in patients undergoing prolonged gold therapy for conditions like rheumatoid arthritis. - It usually manifests as fine, golden deposits in the **cornea** and **lens**, which are generally asymptomatic and do not cause siderosis bulbi. *Copper* - **Copper** deposition in the eye is known as **chalcosis bulbi**, which can result from retained **copper-containing intraocular foreign bodies** or systemic conditions like **Wilson's disease**. - While copper can cause ocular damage, its presentation differs from siderosis bulbi, often characterized by a **Kayser-Fleischer ring** in Wilson's disease or intense inflammation with foreign body. *Selenium* - **Selenium** is an essential trace element, but its ocular toxicity is rare and typically associated with **chronic industrial exposure** or **excessive supplementation**. - It does not directly cause siderosis bulbi; ocular manifestations, if any, are usually non-specific and not related to intraocular foreign bodies.

Question 135: Most common immediate complication of traumatic iridodialysis is

A. Iridoplegia
B. Hyphema (Correct Answer)
C. Angle recession
D. Glaucoma

Explanation: ***Hyphema*** - **Traumatic iridodialysis** involves the tearing of the iris root from the ciliary body at its insertion, which directly damages blood vessels in this highly vascular area - This leads to bleeding into the anterior chamber, causing **hyphema** (collection of blood in anterior chamber) - **Hyphema is the most common immediate complication** of iridodialysis, occurring in the majority of cases - The blood typically settles inferiorly due to gravity, creating a visible fluid level *Iridoplegia* - **Iridoplegia** (traumatic mydriasis) refers to paralysis of the iris sphincter muscle, causing a fixed dilated pupil - While this can occur with severe iris trauma, it is less common than hyphema with iridodialysis - It results from direct damage to the sphincter pupillae muscle or its nerve supply rather than from the iris root avulsion itself *Angle recession* - **Angle recession** is a tear in the ciliary body face between longitudinal and circular muscle fibers - It is a distinct injury that may **coexist** with iridodialysis from the same blunt trauma, but one does not cause the other - Both are separate manifestations of blunt ocular trauma affecting different anatomical structures - Angle recession can lead to late-onset glaucoma in 5-10% of cases *Glaucoma* - **Glaucoma** is a potential **late complication** rather than an immediate result of iridodialysis - Large iridodialysis can cause hypotony initially; small dialysis may lead to chronic drainage angle abnormalities - Secondary glaucoma typically develops months to years after the initial injury - Hyphema is the acute, immediate manifestation directly caused by vascular disruption

Question 136: Commonest site of ocular foreign body lies in

A. Cornea (Correct Answer)
B. Subtarsal sulcus
C. Bulbar conjunctiva
D. Limbus

Explanation: ***Cornea*** - The **cornea** is the **commonest site** for ocular foreign bodies, accounting for the majority of cases seen in clinical practice. - The cornea's **exposed position** on the anterior surface of the eye makes it the primary target for airborne particles, metallic debris, and environmental foreign bodies. - Corneal foreign bodies cause characteristic symptoms including **sharp pain**, **photophobia**, **foreign body sensation**, **lacrimation**, and **blepharospasm**, which typically prompt immediate medical attention. - Common sources include **metallic particles** from grinding or hammering, **dust**, **wood fragments**, and **vegetative matter**. *Subtarsal sulcus* - The subtarsal sulcus (superior palpebral fornix) is a location where foreign bodies can become lodged, particularly under the upper eyelid. - The **upper eyelid's sweeping motion** can trap particles in this groove, causing persistent irritation with each blink. - While clinically significant when they occur, foreign bodies in this location are **less frequent** than corneal foreign bodies. - These typically require **eyelid eversion** for detection and removal. *Bulbar conjunctiva* - Foreign bodies on the bulbar conjunctiva are relatively common but occur less frequently than corneal foreign bodies. - The **bulbar conjunctiva** covers the anterior sclera, and foreign bodies here are typically visible and often easily irrigated out. - The smooth surface makes adherence less likely compared to the corneal epithelium. *Limbus* - The limbus (corneoscleral junction) is a less common site for foreign body lodging. - Foreign bodies at the **limbus** can be particularly bothersome due to its **high innervation** and vascularity. - This location is less frequently affected than the central cornea.

Question 137: 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 138: A 33-year-old patient suffers from blunt trauma to the eye. Fundoscopy shows a cherry red spot, the probable diagnosis is

A. Central Retinal Artery Occlusion (Correct Answer)
B. Retinoblastoma
C. Optic nerve transection
D. Posterior Vitreous Detachment

Explanation: ***Central Retinal Artery Occlusion*** - A **cherry red spot** on fundoscopy is a classic sign of **central retinal artery occlusion (CRAO)**, occurring due to the opaque retina surrounding the fovea, which maintains its blood supply from the choroid. - While blunt trauma can cause CRAO, the primary mechanism is often an **arterial embolism** or thrombus, leading to acute, painless vision loss. *Retinoblastoma* - Retinoblastoma is a **childhood eye cancer** most commonly presenting with **leukocoria** (white pupillary reflex) and strabismus, not typically a cherry red spot. - Although it can present with retinal detachment, the characteristic fundoscopic finding is a **white intraocular mass**, not an ischemic retinal appearance. *Optic nerve transection* - Optic nerve transection results in immediate, severe vision loss and a **positive relative afferent pupillary defect (RAPD)**, but it generally does not cause a cherry red spot. - Fundoscopy after optic nerve transection would initially appear normal, with subsequent **optic disc pallor** developing over weeks to months. *Posterior Vitreous Detachment* - **Posterior vitreous detachment (PVD)** is a common age-related condition presenting with **floaters** and **flashes of light**. - Fundoscopy typically reveals a **Weiss ring** (a ring of glial tissue) and vitreous opacities, not a cherry red spot, and vision loss is often not as sudden or severe as CRAO.

Question 139: Berlin's edema is due to

A. Blunt trauma to eye (Correct Answer)
B. Choroidal melanoma
C. Pars planitis
D. Extradural hemorrhage

Explanation: ***Blunt trauma to eye*** - **Berlin's edema**, also known as **commotio retinae**, is a form of **retinal edema** that occurs after **blunt trauma to the eye**. - The trauma causes a disruption of the photoreceptor outer segments and retinal pigment epithelium, leading to extracellular and intracellular fluid accumulation. *Choroidal melanoma* - This is a **malignant tumor** arising from the melanocytes in the choroid, not caused by trauma. - Presents as a pigmented mass in the choroid and can lead to **retinal detachment** or **vision loss** due to tumor growth. *Pars planitis* - This is a form of **intermediate uveitis**, characterized by inflammation of the pars plana, ciliary body, and peripheral retina. - It is an **inflammatory condition**, not directly caused by acute trauma, and often presents with **floaters** and **blurred vision**. *Extradural hemorrhage* - This refers to bleeding between the inner surface of the skull and the dura mater, typically in the brain. - It is a **neurological emergency** usually caused by head injury, and its direct effect is not Berlin's edema in the eye.

Question 140: Sympathetic ophthalmitis results from -

A. Penetrating injury of ciliary body (Correct Answer)
B. Glaucoma
C. Blunt trauma to the eye
D. Trachoma

Explanation: ***Penetrating injury of ciliary body*** - **Sympathetic ophthalmitis** is a rare, bilateral granulomatous panuveitis that occurs after a **penetrating ocular trauma** or intraocular surgery, most commonly involving the ciliary body or uveal tissue. - The injury exposes hidden **uveal antigens** to the immune system, leading to a delayed-type hypersensitivity reaction against the fellow (non-injured) eye. - Typically develops weeks to months after the initial injury. *Glaucoma* - **Glaucoma** is a group of eye conditions that damage the optic nerve, often due to elevated intraocular pressure. - It is a consequence or complication of ocular trauma, not a cause of sympathetic ophthalmitis. - Does not involve the autoimmune mechanism seen in sympathetic ophthalmitis. *Blunt trauma to the eye* - **Blunt trauma** can cause various ocular complications (hyphema, angle recession, retinal detachment) but does not typically expose uveal antigens. - Sympathetic ophthalmitis specifically requires **penetrating injury** that disrupts the integrity of the uveal tissue. - The key distinction is penetrating vs. blunt mechanism of injury. *Trachoma* - **Trachoma** is a chronic eye infection caused by *Chlamydia trachomatis*, primarily affecting the conjunctiva and cornea. - It is an infectious process and not related to penetrating trauma or autoimmune response to uveal antigens. - Represents a completely different disease mechanism (infectious vs. autoimmune).

Practice by Chapter

Classification of Ocular Trauma

Practice Questions

Blunt Trauma

Practice Questions

Penetrating and Perforating Injuries

Practice Questions

Intraocular Foreign Bodies

Practice Questions

Chemical Injuries

Practice Questions

Thermal and Radiation Injuries

Practice Questions

Orbital Trauma

Practice Questions

Traumatic Optic Neuropathy

Practice Questions

Ocular Manifestations of Child Abuse

Practice Questions

Sports-Related Eye Injuries

Practice Questions

Ocular Trauma Management Principles

Practice Questions

Rehabilitation After Ocular Trauma

Practice Questions

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