Conjunctival Trauma — MCQs
True about acid injury to eye are all except?
In a patient with head injury black eye associated with subconjunctival hemorrhage occurs when there is
What is the most likely complication of the condition shown in the image below?
Which of the following conditions does not typically cause subconjunctival hemorrhages?
What is the first aid treatment for acid contact with the skin?
Which of the following is a known complication of vernal keratoconjunctivitis?
Perforating injuries with retained intraocular foreign body are more serious than those without because of:
What is the primary cause of snow blindness?
Epithelial xerosis of conjunctiva is caused by?
NOT a feature of trachoma:
Conjunctival Trauma Indian Medical PG Practice Questions and MCQs
Question 1: True about acid injury to eye are all except?
- A. more destructive than alkali injuries (Correct Answer)
- B. steroids are used to control inflammation
- C. makes a barrier and prevent deeper penetration
- D. glaucoma is most preventable complication following acid injury
Explanation: ***more destructive than alkali injuries*** - This statement is **false**. **Alkali burns** are generally more severe than acid burns because alkalis have **liquefactive necrosis**, which allows them to penetrate deeper into ocular tissues. - Acids cause **coagulative necrosis**, which forms a protective barrier that limits further penetration, making them typically less destructive than alkali injuries. *steroids are used to control inflammation* - **Topical corticosteroids** are commonly used in the management of ocular chemical burns, including acid injuries, to help **control inflammation** and reduce the risk of secondary complications. - However, their use must be carefully monitored due to potential side effects like increased intraocular pressure and delayed corneal healing. *makes a barrier and prevent deeper penetration* - **Acidic substances** cause **coagulative necrosis** of the superficial tissues, which creates a protective barrier of denatured proteins. - This barrier helps to prevent the acid from penetrating deeper into the ocular structures, thus often limiting the extent of damage compared to alkali burns. *glaucoma is most preventable complication following acid injury* - **Glaucoma** is indeed a significant complication of ocular acid injuries and can be prevented through **immediate copious irrigation**, control of inflammation, and monitoring of intraocular pressure. - While various complications can occur (corneal opacification, symblepharon, limbal stem cell deficiency), glaucoma prevention through early intervention and appropriate medical management is a key focus in acute management, making this statement acceptable as true.
Question 2: In a patient with head injury black eye associated with subconjunctival hemorrhage occurs when there is
- A. Fracture of roof and anterior cranial fossa (Correct Answer)
- B. Bleeding between the skin and galea aponeurotica
- C. Hemorrhage between galea aponeurotica and pericranium
- D. Fracture of greater wing of sphenoid bone
Explanation: ***Fracture of roof and anterior cranial fossa*** - A **fracture involving the anterior cranial fossa** can lead to extravasation of blood into the periorbital tissues, causing a **"raccoon eyes"** or **periorbital ecchymosis** appearance. - This blood can track forward into the subconjunctival space, resulting in **subconjunctival hemorrhage**. *Bleeding between the skin and galea aponeurotica* - Bleeding in this superficial plane would lead to a **subgaleal hematoma** or scalp swelling, but it typically does not directly extend to cause a black eye or subconjunctival hemorrhage. - The **galea aponeurotica** is superficial to the orbit and does not directly communicate with the orbital contents in a way that would cause these specific signs. *Hemorrhage between galea aponeurotica and pericranium* - This space is known as the **subgaleal space** and bleeding here would manifest as a diffuse, fluctuating swelling of the scalp. - It is separated from the orbital contents by the **supraorbital ridge** and orbital septum, making it unlikely to directly cause a black eye and subconjunctival hemorrhage without a direct fracture communication. *Fracture of greater wing of sphenoid bone* - A fracture of the **greater wing of the sphenoid** is located more posteriorly and laterally in the skull base. - While significant, it is less likely to directly cause **periorbital ecchymosis** and **subconjunctival hemorrhage** compared to a fracture of the anterior cranial fossa, which is anatomically closer to the orbits.
Question 3: What is the most likely complication of the condition shown in the image below?
- A. Exposure Keratitis (Correct Answer)
- B. Difficulty in eye movement
- C. Cataract
- D. Glaucoma
Explanation: ***Exposure Keratitis*** - The image shows **proptosis** (exophthalmos) of the right eye, where the eyeball protrudes forward. This condition often leads to incomplete eyelid closure (lagophthalmos). - **Exposure keratitis** occurs when the cornea is inadequately covered by the eyelids, leading to drying and damage due to constant exposure to air and environmental factors. *Difficulty in eye movement* - While **proptosis** can sometimes be associated with restricted eye movements (e.g., in severe Graves' ophthalmopathy due to muscle swelling), it is not the **most likely direct complication** of the exposure itself. - The image primarily depicts the physical displacement of the globe, which predisposes to corneal issues, not necessarily oculomotor dysfunction as the primary complication. *Cataract* - **Cataracts** are opacities of the lens and are typically associated with aging, trauma, or certain systemic conditions (e.g., diabetes, steroid use). - They are not a direct or common complication of **proptosis** or the resulting **exposure of the ocular surface**. *Glaucoma* - **Glaucoma** is a group of conditions characterized by damage to the optic nerve, often due to elevated intraocular pressure. - While severe **proptosis** leading to orbital congestion can theoretically increase intraocular pressure, it is not the most direct or prevalent complication compared to **exposure keratitis**, which is a direct consequence of inadequate globe protection.
Question 4: Which of the following conditions does not typically cause subconjunctival hemorrhages?
- A. Whooping cough
- B. Scurvy
- C. Pellagra (Correct Answer)
- D. Purpura
Explanation: ***Pellagra*** - Pellagra is a **nutritional deficiency disease** caused by a lack of **niacin (vitamin B3)**, characterized by symptoms affecting the **skin, gastrointestinal tract, and nervous system** (dermatitis, diarrhea, dementia, and death if untreated) [1]. - It does **not typically cause subconjunctival hemorrhages** as it primarily affects other organ systems and isn't associated with vascular fragility in the conjunctiva like the other conditions listed [2]. *Whooping cough* - **Violent coughing paroxysms** in whooping cough (pertussis) can significantly increase **venous pressure in the head and neck**. - This elevated pressure can rupture small conjunctival blood vessels, leading to **subconjunctival hemorrhages**. *Scurvy* - Scurvy is caused by **vitamin C deficiency**, which is essential for collagen synthesis and maintaining **blood vessel integrity**. - Lack of vitamin C leads to **fragile capillaries**, making patients prone to bleeding, including **subconjunctival hemorrhages**. *Purpura* - Purpura refers to **purple-colored spots on the skin caused by bleeding underneath the skin**. It is a general term for various conditions characterized by **small vessel bleeding**. - These conditions often involve **vascular fragility or platelet abnormalities**, making individuals susceptible to bleeding in different sites, including the conjunctiva, resulting in **subconjunctival hemorrhages**.
Question 5: What is the first aid treatment for acid contact with the skin?
- A. Wash with strong alkali
- B. Wash with copious amounts of water (Correct Answer)
- C. Refer to higher centre
- D. Wash with mild alkali agent
Explanation: ***Wash with copious amounts of water*** - The primary first aid for acid contact with the skin is immediate and prolonged **irrigation with copious amounts of water**. This helps to dilute the acid and wash away residual chemicals, minimizing tissue damage. - Flushing should continue for at least **20-30 minutes** or until medical help arrives, even if the pain subsides, to ensure thorough removal of the corrosive agent. *Wash with strong alkali* - Using a strong alkali to neutralize an acid burn can lead to an **exothermic reaction**, generating significant heat and causing further tissue damage. - This approach carries a high risk of worsening the chemical burn and should be strictly avoided. *Refer to higher centre* - While referral to a higher center may be necessary for severe burns, it is not the **immediate first aid step**. Delaying initial management to seek advanced care can worsen the burn. - **Immediate irrigation** is crucial to prevent further chemical injury and should precede any transfer decisions. *Wash with mild alkali agent* - Similar to strong alkalis, even a mild alkali agent can cause an **exothermic reaction** when mixed with acid on the skin, potentially increasing tissue damage rather than mitigating it. - The most effective and safest approach is **dilution with water**, not neutralization with bases.
Question 6: Which of the following is a known complication of vernal keratoconjunctivitis?
- A. Keratoconus (Correct Answer)
- B. Retinal detachment
- C. Vitreous hemorrhage
- D. Cataract
Explanation: ***Keratoconus*** - **Vernal keratoconjunctivitis (VKC)** is a chronic allergic eye condition associated with persistent eye rubbing, which can lead to thinning and bulging of the cornea, a condition known as **keratoconus**. - Long-term inflammation and mechanical stress from allergic reactions and *eye rubbing* contribute to the corneal structural changes seen in keratoconus. - This is the **most common and well-recognized complication** of VKC. *Cataract* - While cataracts can occur in VKC patients (particularly from **chronic topical steroid use** or severe disease with shield ulcers), they are **less common than keratoconus** as a direct complication. - Keratoconus remains the more characteristic and frequently encountered complication specifically associated with the mechanical trauma of eye rubbing in VKC. *Retinal detachment* - **Retinal detachment** is a condition where the retina separates from its underlying support tissues and is typically associated with trauma, high myopia, or diabetic retinopathy, not VKC. - VKC primarily affects the conjunctiva and cornea, and its inflammatory processes do not directly cause retinal detachment. *Vitreous hemorrhage* - **Vitreous hemorrhage** involves bleeding into the gel-like substance that fills the eye and is commonly caused by conditions like diabetic retinopathy or retinal tears, not VKC. - VKC does not involve the posterior segment of the eye in a way that would lead to vitreous hemorrhage.
Question 7: Perforating injuries with retained intraocular foreign body are more serious than those without because of:
- A. All of the options
- B. More chances of infection
- C. Deleterious effects of foreign bodies (Correct Answer)
- D. More chances of sympathetic ophthalmitis
Explanation: ***Deleterious effects of foreign bodies*** - This is the **MOST SPECIFIC and PRIMARY reason** that distinguishes retained IOFBs from perforating injuries without retained foreign bodies. - Retained intraocular foreign bodies cause **direct toxic effects** on ocular tissues depending on their composition: **siderosis bulbi** from iron (causing rust-colored deposits, retinal degeneration, and vision loss), **chalcosis** from copper (greenish deposits and inflammation), and direct mechanical trauma to delicate intraocular structures. - These **material-specific toxic effects** are unique to retained foreign bodies and occur regardless of whether infection or inflammation develops. - The foreign body acts as a constant source of **chronic inflammation and tissue damage**, leading to complications like cataract, glaucoma, retinal detachment, and progressive vision loss. *More chances of infection* - While retained IOFBs do increase the risk of **endophthalmitis** (severe intraocular infection), infection risk exists with any perforating injury, whether or not a foreign body is retained. - The question asks what makes retained IOFB cases **MORE serious** - the infection risk is elevated but not the PRIMARY distinguishing feature. - Prophylactic antibiotics can reduce infection risk, but cannot prevent the direct toxic effects of the retained material. *More chances of sympathetic ophthalmitis* - Sympathetic ophthalmitis is a rare bilateral granulomatous uveitis that can occur after **penetrating ocular trauma with uveal tissue injury**. - This risk exists with perforating injuries in general, not specifically because of the retained foreign body itself. - The presence of a foreign body is less important than uveal prolapse and inflammation in triggering this immune-mediated response. *All of the options* - While infection and sympathetic ophthalmitis are legitimate concerns, they are **not specific to retained foreign bodies** - they can occur with any penetrating injury. - The **direct deleterious/toxic effects** of the foreign body material (siderosis, chalcosis, mechanical damage) are the PRIMARY and MOST SPECIFIC reason that makes retained IOFB cases more serious. - This option is incorrect because it doesn't distinguish the unique hazard posed by the retained foreign body itself.
Question 8: What is the primary cause of snow blindness?
- A. UV rays (Correct Answer)
- B. Infrared radiation
- C. Microwave radiation
- D. Defect in optical devices
Explanation: **UV rays** - **Snow blindness**, clinically known as **photokeratitis**, is primarily caused by exposure of the eyes to high levels of **ultraviolet (UV) radiation**. - This radiation is particularly intense in snow-covered environments due to the **high reflectivity of snow**, which can reflect up to 80% of UV rays, effectively exposing the eyes to double the amount of UV. *Infrared radiation* - While infrared radiation can cause **heat-related injury** to the eyes (e.g., glassblower's cataract), it does not directly lead to the corneal damage characteristic of snow blindness. - Infrared radiation is sensed as heat and is not responsible for the **phototoxic effect** on the cornea. *Microwave radiation* - Microwave radiation can cause internal heating of tissues, but it is not a direct cause of photokeratitis or snow blindness. - Exposure to high levels of microwave radiation can lead to other ocular issues like **cataracts**, but through different mechanisms. *Defect in optical devices* - While defective optical devices (e.g., sunglasses without proper UV protection) can *contribute* to snow blindness by failing to block UV radiation, they are not the primary cause themselves. - The underlying harmful agent is the **UV radiation**, and the defect merely allows the exposure to occur.
Question 9: Epithelial xerosis of conjunctiva is caused by?
- A. Xerophthalmia (Correct Answer)
- B. Infectious conjunctivitis caused by Chlamydia trachomatis
- C. Autoimmune blistering conjunctivitis
- D. Bacterial conjunctivitis due to Corynebacterium diphtheriae
Explanation: ***Xerophthalmia*** - **Xerophthalmia** is a medical condition characterized by **dryness of the eye**, often due to **vitamin A deficiency**. - **Epithelial xerosis of the conjunctiva** is one of the early and hallmark signs of xerophthalmia, representing the drying and thickening of the conjunctival epithelium due to goblet cell loss and squamous metaplasia. *Infectious conjunctivitis caused by Chlamydia trachomatis* - This typically causes **trachoma**, characterized by chronic inflammation, scarring, and eventual blindness. - While it can lead to dryness and scarring in later stages due to **symblepharon** or **entropion**, it does not primarily manifest as epithelial xerosis. *Autoimmune blistering conjunctivitis* - This condition involves **immune-mediated inflammation** leading to subepithelial blistering, scarring, and shrinkage of the conjunctiva. - It results in significant **ocular surface damage** and vision loss but is distinct from the primary epithelial changes seen in xerosis due to vitamin A deficiency. *Bacterial conjunctivitis due to Corynebacterium diphtheriae* - **Diphtheritic conjunctivitis** is a severe form of bacterial conjunctivitis that causes a distinctive **"pseudomembrane"** on the conjunctiva. - It leads to acute inflammation and potentially systemic illness, not primarily epithelial xerosis.
Question 10: NOT a feature of trachoma:
- A. Entropion
- B. Corneal opacity
- C. Chalazion (Correct Answer)
- D. Herbert's pits
Explanation: ***Chalazion*** - A **chalazion** is a **lipogranulomatous inflammation** of a **meibomian gland** and is not directly caused by *Chlamydia trachomatis* infection, though chronic inflammation could theoretically predispose to it. - While chronic inflammation of the eyelids in trachoma can cause various complications, a chalazion is a distinct condition related to meibomian gland dysfunction and is not a direct, defining feature of trachoma. *Entropion* - **Entropion**, the **inward turning of the eyelid margin**, is a severe late complication of trachoma caused by conjunctival scarring and contraction. - This inward turning leads to **trichiasis** (**misdirected eyelashes**), which abrades the cornea. *Corneal opacity* - **Corneal opacity** is a common and serious consequence of chronic trachoma, resulting from repeated **corneal abrasions** by misdirected eyelashes (trichiasis) and chronic inflammation. - This scarring can lead to **severe vision impairment** and **blindness**. *Herbert's pits* - **Herbert's pits** are characteristic depressions on the **limbus** (corneoscleral junction) formed after the resolution of **limbal follicles** in chronic trachoma. - They are a diagnostic sign of past or present trachomatous infection.
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