Diseases of the Conjunctiva Practice Questions

Q: A 4-year-old child presents to the Pediatric OPD with a complaint of inability to see at night for the last few days. The pediatrician suspects a vitamin deficiency. If clinical signs of vitamin A deficiency occur, what would be the first clinical sign?

Conjunctival xerosis. **Explanation:** Vitamin A (Retinol) is essential for maintaining the integrity of epithelial surfaces and the phototransduction cycle. In Vitamin A deficiency (VAD), the earliest functional symptom is **Night Blindness (Nyctalopia)**; however, the question asks for the **first clinical sign**. **Why C is correct:** **Conjunctival xerosis (X1B)** is the first objective clinical sign of Vitamin A deficiency. It is characterized by the conjunctiva becoming dry, lusterless, and non-wettable, often appearing "muddy" or wrinkled. This occurs due to the loss of goblet cells and keratinization of the conjunctival epithelium. **Analysis of Incorrect Options:** * **A. Retinal detachment:** This is not a feature of Vitamin A deficiency. VAD affects the retina via **Xerophthalmic Fundus (XF)** (pale spots), but not detachment. * **B. Bitot spot (X1B):** These are triangular, foamy, silvery-white patches on the bulbar conjunctiva. While highly characteristic of VAD, they appear **after** conjunctival xerosis has already initiated. * **D. Corneal xerosis (X2):** This represents a more advanced stage where the cornea becomes hazy and dry. It is a medical emergency as it precedes keratomalacia (corneal melting). **NEET-PG High-Yield Pearls (WHO Classification of Xerophthalmia):** * **X1A:** Night Blindness (Earliest **symptom**) * **X1B:** Conjunctival Xerosis (Earliest **sign**) * **X2:** Bitot’s Spots * **X3:** Corneal Xerosis * **X3A/X3B:** Keratomalacia ( 1/3 of corneal surface) * **Treatment:** For a 4-year-old (>1 year), the dose is **200,000 IU** orally on days 0, 1, and 14. (Half dose for 6–12 months; 50,000 IU for <6 months).

Q: Conjunctivitis is seen in all except:

Cytomegalovirus (CMV). **Explanation:** The correct answer is **A. Cytomegalovirus (CMV)**. In ophthalmology, CMV is primarily associated with **retinitis** (posterior segment involvement), particularly in immunocompromised individuals such as those with HIV/AIDS (CD4 count <50 cells/µL). It classically presents as "pizza-pie" or "cheese and ketchup" fundus. CMV does **not** typically cause conjunctivitis. **Analysis of Options:** * **Adenovirus (Option B):** This is the most common cause of viral conjunctivitis. It manifests as **Pharyngoconjunctival Fever (PCF)** (Serotypes 3, 7) or **Epidemic Keratoconjunctivitis (EKC)** (Serotypes 8, 19, 37). * **Coxsackie A–24 (Option C) & Enterovirus 70 (Option D):** These are the classic causative agents of **Acute Hemorrhagic Conjunctivitis (AHC)**. This condition is characterized by rapid onset, painful swelling, and pathognomonic subconjunctival hemorrhages. **Clinical Pearls for NEET-PG:** * **Follicular Reaction:** Viral conjunctivitis typically presents with a follicular response in the inferior palpebral conjunctiva. * **Pre-auricular Lymphadenopathy:** A high-yield clinical sign often associated with viral conjunctivitis (especially Adenoviral). * **Hemorrhagic Conjunctivitis:** If a question mentions a "sudden outbreak" or "epidemic" with subconjunctival spots of blood, think Enterovirus 70 or Coxsackie A-24. * **CMV Treatment:** The drug of choice for CMV retinitis is **Ganciclovir** (or Valganciclovir/Foscarnet).

Q: Which of the following is a significant distinguishing feature of viral conjunctivitis?

Clear discharge. **Explanation:** Viral conjunctivitis, most commonly caused by **Adenovirus**, is characterized by a non-specific inflammatory response of the conjunctiva. The hallmark of viral infection is a **serous or watery (clear) discharge**. This occurs because the viral pathogen triggers a lymphocytic response and increased lacrimation without the significant recruitment of polymorphonuclear leukocytes (neutrophils) that characterize bacterial infections. **Analysis of Options:** * **Option C (Correct):** Clear, watery discharge is the classic presentation of viral conjunctivitis. It is often associated with follicular hypertrophy and preauricular lymphadenopathy. * **Option A (Incorrect):** Viral conjunctivitis typically presents with a "gritty" or foreign body sensation and itching, rather than significant eye pain. Severe pain (photophobia) usually suggests corneal involvement (keratitis) or uveitis. * **Option B (Incorrect):** Purulent or mucopurulent discharge is the hallmark of **Bacterial Conjunctivitis**. The "globular" nature refers to the accumulation of dead neutrophils and cellular debris, which is not seen in viral etiologies. * **Option D (Incorrect):** This is an incomplete distractor. **High-Yield Clinical Pearls for NEET-PG:** * **Pharyngoconjunctival Fever (PCF):** Caused by Adenovirus types **3 and 7**; presents with fever, pharyngitis, and follicular conjunctivitis. * **Epidemic Keratoconjunctivitis (EKC):** Caused by Adenovirus types **8, 11, and 19**; more severe, highly contagious, and often leads to subepithelial corneal opacities. * **Key Sign:** The presence of **preauricular lymphadenopathy** is a vital clinical clue pointing toward a viral rather than a bacterial cause.

Q: Which of the following is NOT a cause of tear film deficiency?

Systemic Vitamin C deficiency. To understand tear film deficiency, one must recall the three layers of the tear film: **Mucin** (inner), **Aqueous** (middle), and **Lipid** (outer). A deficiency in any of these leads to Dry Eye Disease (Keratoconjunctivitis Sicca). ### Why "Systemic Vitamin C deficiency" is the correct answer: Vitamin C (Ascorbic acid) is essential for collagen synthesis and wound healing. While its deficiency causes Scurvy (leading to corkscrew hair and bleeding gums), it is **not** a primary cause of tear film deficiency. In contrast, **Vitamin A deficiency** is a major cause of tear film instability because it leads to the loss of conjunctival goblet cells, resulting in mucin deficiency and Xerophthalmia. ### Analysis of Incorrect Options: * **Infiltrative disease of lacrimal glands:** Conditions like Sarcoidosis, Lymphoma, or Amyloidosis destroy the lacrimal acini, leading to **Aqueous deficiency**. * **Post corneal transplant:** Corneal surgery (including Keratoplasty and LASIK) severs the long ciliary nerves. This causes **neurotrophic epitheliopathy**, decreasing the sensory feedback loop to the lacrimal gland, thereby reducing tear production. * **Congenital absence of meibomian glands:** Meibomian glands produce the lipid layer. Their absence or dysfunction (MGD) leads to **evaporative tear film deficiency**, as the aqueous layer evaporates rapidly without the protective lipid seal. ### High-Yield Clinical Pearls for NEET-PG: * **Schirmer’s Test I:** Measures total tear secretion (Normal: >15mm in 5 mins). <5mm is diagnostic of dry eye. * **Tear Film Break-up Time (TBUT):** Measures mucin/lipid stability. Normal is 15–35 seconds; <10 seconds indicates instability. * **Sjögren’s Syndrome:** A classic triad of dry eyes, dry mouth, and connective tissue disease (e.g., Rheumatoid Arthritis). * **Vitamin A:** Essential for maintaining the health of the non-keratinized squamous epithelium of the conjunctiva.

Q: What is the term for a white plaque in the eye caused by vitamin A deficiency?

Bitot spot. **Explanation:** **Bitot’s spots** are the hallmark clinical sign of Vitamin A deficiency (Xerophthalmia). They are characterized by triangular, foamy, silvery-white plaques typically located on the bulbar conjunctiva, most commonly in the temporal quadrant. The underlying medical concept involves **squamous metaplasia** of the conjunctival epithelium. Vitamin A is essential for maintaining goblet cells; its deficiency leads to a loss of these cells and keratinization of the conjunctiva. The "foamy" appearance is caused by the accumulation of keratin debris and the gas-producing bacilli, *Corynebacterium xerosis*. **Analysis of Incorrect Options:** * **Pink spot:** This is not a standard ophthalmological term. It may be confused with a "Cherry-red spot," which is seen in Central Retinal Artery Occlusion (CRAO) or Tay-Sachs disease. * **White spot:** While Bitot’s spots are white, this is a generic descriptive term and not the specific medical eponym required for the diagnosis. * **Herald spot:** This term is associated with dermatology (the "Herald patch" in Pityriasis rosea), not ophthalmology. **High-Yield Clinical Pearls for NEET-PG:** * **WHO Classification:** Bitot’s spots are classified as stage **X1B** of Xerophthalmia. * **Reversibility:** Bitot’s spots in children are usually reversible with high-dose Vitamin A therapy, but in adults, they may persist as permanent sequelae of past deficiency. * **Night Blindness (Nyctalopia):** This is the earliest clinical symptom (X1A) of Vitamin A deficiency, whereas Bitot’s spots are the most common objective sign. * **Treatment:** The WHO protocol for children >1 year is 200,000 IU of Vitamin A orally on days 0, 1, and 14.

Q: Which drug should be avoided in a case of spring catarrh?

Antibiotics. **Explanation:** **Spring Catarrh (Vernal Keratoconjunctivitis - VKC)** is a bilateral, recurrent, seasonal allergic inflammation of the conjunctiva, primarily driven by a Type I hypersensitivity reaction to allergens like pollen. **Why Antibiotics are avoided:** The underlying pathology of VKC is **allergic**, not bacterial. Antibiotics have no therapeutic role in treating an allergy. Furthermore, their unnecessary use is contraindicated because: 1. They can cause **medicamentosa** (drug-induced conjunctivitis), worsening the patient's discomfort. 2. They contribute to **antimicrobial resistance**. 3. They may cause hypersensitivity reactions in an already sensitized ocular surface. **Analysis of Incorrect Options:** * **Methylcellulose (Lubricants):** These are beneficial as they provide a barrier against allergens and wash away inflammatory mediators from the ocular surface. * **Steroids:** These are the "gold standard" for managing acute exacerbations of VKC due to their potent anti-inflammatory action. However, they must be used under supervision to avoid glaucoma and cataracts. * **Antihistamines:** These are a mainstay of treatment (often combined with mast cell stabilizers) to provide symptomatic relief from itching. **High-Yield Clinical Pearls for NEET-PG:** * **Hallmark symptoms:** Intense itching, ropy discharge, and photophobia. * **Key signs:** Cobblestone papillae (Palpebral form), Horner-Trantas dots (Limbal form), and Shield ulcers (Corneal involvement). * **Treatment Ladder:** Mast cell stabilizers (Cromolyn) for prophylaxis → Topical Antihistamines → Topical Steroids (for pulses) → Cyclosporine/Tacrolimus (for steroid-sparing).

Q: Which bacterium does NOT cause ophthalmia neonatorum?

Moraxella. **Explanation:** **Ophthalmia Neonatorum** is defined as bilateral inflammation of the conjunctiva occurring within the first 30 days of life. It is a medical emergency because certain pathogens can lead to corneal perforation and permanent blindness. **Why Moraxella is the correct answer:** While *Moraxella lacunata* is a well-known cause of **angular conjunctivitis** in adults and older children, it is not a recognized cause of ophthalmia neonatorum. The etiology of neonatal conjunctivitis is strictly categorized into chemical, bacterial (specifically those colonizing the maternal birth canal), and viral causes. **Analysis of incorrect options:** * **Chlamydia trachomatis (Serotypes D-K):** The most common infectious cause worldwide. It typically presents 5–14 days after birth. * **Neisseria gonorrhoeae:** The most serious cause. It presents early (2–5 days) with profuse purulent discharge and can penetrate an intact corneal epithelium, leading to perforation. * **Pseudomonas aeruginosa:** Though less common than Chlamydia, it is a recognized bacterial cause that can occur in hospital settings (NICU) or via contaminated equipment. It is highly destructive to the neonatal cornea. **High-Yield Clinical Pearls for NEET-PG:** * **Incubation Periods (The "Golden Rule"):** * *Chemical (Silver Nitrate):* 0–24 hours. * *Gonococcus:* 2–5 days (Most hyperacute). * *Chlamydia:* 5–14 days (Most common). * *Herpes Simplex (HSV-2):* 1–2 weeks. * **Prophylaxis:** 1% Silver nitrate (Credé’s method) or 0.5% Erythromycin ointment. * **Treatment:** Systemic treatment is mandatory for Chlamydia (Oral Erythromycin) and Gonococcus (Ceftriaxone) to prevent systemic complications like pneumonia or sepsis.

Q: Which of the following conjunctivitis can also involve the intact cornea?

Acute purulent conjunctivitis. **Explanation:** The correct answer is **Acute purulent conjunctivitis** (also known as Hyperacute conjunctivitis). **1. Why the correct answer is right:** The hallmark of acute purulent conjunctivitis, most commonly caused by *Neisseria gonorrhoeae* or *Neisseria meningitidis*, is its ability to invade an **intact corneal epithelium**. Most bacteria require a pre-existing epithelial defect to cause a corneal ulcer; however, certain organisms possess virulent enzymes (proteases) that allow them to penetrate healthy corneal tissue directly. This can lead to rapid corneal perforation and endophthalmitis if not treated urgently. **2. Why the incorrect options are wrong:** * **A. Acute mucopurulent conjunctivitis:** Typically caused by *Staphylococcus aureus* or *Streptococcus pneumoniae*. While it causes significant discharge and "red eye," it does not involve the cornea unless there is prior trauma or severe drying. * **B. Acute membranous conjunctivitis:** Classically caused by *Corynebacterium diphtheriae*. While it can cause corneal scarring due to the severity of the inflammation and membrane formation, it does not typically penetrate an intact cornea as aggressively as *Neisseria*. * **C. Angular conjunctivitis:** Caused by *Moraxella axenfelditis*. It is characterized by excoriation of the skin at the inner and outer canthi due to proteases, but it does not involve the central cornea. **3. Clinical Pearls for NEET-PG:** * **Mnemonic for organisms that can penetrate intact cornea:** "**CHLNS**" * **C**orynebacterium diphtheriae * **H**aemophilus aegyptius * **L**isteria monocytogenes * **N**eisseria gonorrhoeae / meningitidis * **S**higella * **Treatment:** Purulent conjunctivitis due to *N. gonorrhoeae* is a medical emergency requiring systemic Ceftriaxone. * **Clinical Sign:** Look for "copious, thick, creamy pus" dripping from the eyelids.

Q: Circumcorneal congestion is seen in all of the following conditions, EXCEPT:

Moraxella infection. **Explanation:** The key to answering this question lies in differentiating between **Circumcorneal (Ciliary) Congestion** and **Conjunctival Congestion**. **Why Moraxella infection is the correct answer:** Moraxella lacunata typically causes **Angular Conjunctivitis**. This condition is characterized by **conjunctival congestion** (superficial vessels) localized specifically to the inner and outer canthi (angles) of the eye. It does not involve the deep ciliary vessels. Therefore, it presents with superficial redness rather than circumcorneal congestion. **Analysis of Incorrect Options:** Circumcorneal congestion involves the deep ciliary vessels and is a hallmark of **keratitis, iridocyclitis, or acute glaucoma**. * **Anterior Uveitis (Iridocyclitis):** Inflammation of the uveal tract triggers deep ciliary vessel engorgement, presenting as a typical dusky-red circumcorneal flush. * **Acute Congestive Glaucoma:** The sudden, massive rise in intraocular pressure leads to venous stasis and intense ciliary congestion. * **Stevens-Johnson Syndrome (SJS):** In the acute phase, SJS causes severe ocular surface inflammation, including intense conjunctivitis and often secondary keratitis or corneal involvement, which leads to circumcorneal congestion. **NEET-PG High-Yield Pearls:** 1. **Ciliary Congestion:** Vessels are deep, purple/dusky red, do not move with the conjunctiva, and do not blanch with 1:1000 adrenaline. It indicates serious intraocular pathology. 2. **Conjunctival Congestion:** Vessels are superficial, bright red, move with the conjunctiva, and **blanch with adrenaline**. It indicates superficial pathology (conjunctivitis). 3. **Moraxella Lacunata:** Classically associated with "maceration of the skin at the angles" due to the production of a proteolytic enzyme (protease). Treatment is Zinc Oxide or Oxytetracycline.

Q: What type of corneal ulcer is typically seen in Vernal keratoconjunctivitis?

Shield ulcer. ### Explanation **Correct Answer: D. Shield ulcer** **Mechanism and Pathophysiology:** Vernal Keratoconjunctivitis (VKC) is a bilateral, recurrent, allergic inflammation of the conjunctiva, typically affecting young boys. A **Shield Ulcer** is a characteristic corneal complication seen in the palpebral or mixed forms of VKC. It is a **sterile, indolent, oval, or transversely oriented** epithelial defect located in the upper part of the cornea. The pathogenesis involves two factors: 1. **Mechanical:** Constant rubbing of the cornea by hard, "cobblestone" papillae on the superior palpebral conjunctiva. 2. **Chemical:** Inflammatory mediators and "Major Basic Protein" (MBP) released from eosinophils inhibit corneal epithelial healing, leading to a non-healing ulcer with a plaque-like base of mucus and fibrin. **Analysis of Incorrect Options:** * **A. Dendritic pattern:** Characterized by linear, branching ulcers with terminal bulbs; pathognomonic for **Herpes Simplex Keratitis** (epithelial). * **B. Pseudodendritic pattern:** Similar to dendritic but lacks terminal bulbs and is more elevated. Seen in **Herpes Zoster Ophthalmicus**, Acanthamoeba keratitis, or Tyrosinemia Type II. * **C. Geological (Geographic) ulcer:** A large, amoeboid-shaped ulcer formed when dendritic ulcers coalesce, often worsened by the inappropriate use of topical steroids in HSV keratitis. **High-Yield Clinical Pearls for NEET-PG:** * **VKC Triad:** Cobblestone papillae (palpebral), Horner-Trantas dots (limbal), and Shield ulcer (corneal). * **Maxwell-Lyons Sign:** A "ropy" discharge characteristic of VKC. * **Treatment of Shield Ulcer:** Includes topical steroids, mast cell stabilizers, and sometimes surgical debridement of the plaque to allow re-epithelialization. * **Classification:** Shield ulcers are graded (Stage 1-3) based on the presence of plaque and depth of the ulcer.

Question 1

A 4-year-old child presents to the Pediatric OPD with a complaint of inability to see at night for the last few days. The pediatrician suspects a vitamin deficiency. If clinical signs of vitamin A deficiency occur, what would be the first clinical sign?

Accepted Answer

Conjunctival xerosis

Answer

Retinal detachment

Answer

Bitot spot

Answer

Corneal xerosis

Question 2

Conjunctivitis is seen in all except:

Accepted Answer

Cytomegalovirus (CMV)

Answer

Adenovirus

Answer

Coxsackie A–24

Answer

Enterovirus 70

Question 3

Which of the following is a significant distinguishing feature of viral conjunctivitis?

Accepted Answer

Clear discharge

Answer

Significant eye pain

Answer

Globular purulent discharge

Answer

Eye

Question 4

Which of the following is NOT a cause of tear film deficiency?

Accepted Answer

Systemic Vitamin C deficiency

Answer

Infiltrative disease of lacrimal glands

Answer

Post corneal transplant

Answer

Congenital absence of meibomian glands

Question 5

What is the term for a white plaque in the eye caused by vitamin A deficiency?

Accepted Answer

Bitot spot

Answer

Pink spot

Answer

White spot

Answer

Herald spot

Question 6

Which drug should be avoided in a case of spring catarrh?

Accepted Answer

Antibiotics

Answer

Methylcellulose eyedrops

Answer

Steroids

Answer

Antihistamine

Question 7

Which bacterium does NOT cause ophthalmia neonatorum?

Accepted Answer

Moraxella

Answer

Chlamydia

Answer

Gonococcus

Answer

Pseudomonas

Question 8

Which of the following conjunctivitis can also involve the intact cornea?

Accepted Answer

Acute purulent conjunctivitis

Answer

Acute mucopurulent conjunctivitis

Answer

Acute membranous conjunctivitis

Answer

Angular conjunctivitis

Question 9

Circumcorneal congestion is seen in all of the following conditions, EXCEPT:

Accepted Answer

Moraxella infection

Answer

Anterior uveitis

Answer

Acute congestive glaucoma

Answer

Stevens-Johnson syndrome

Question 10

What type of corneal ulcer is typically seen in Vernal keratoconjunctivitis?

Accepted Answer

Shield ulcer

Answer

Dendritic pattern

Answer

Pseudodendritic pattern

Answer

Geological ulcer

Diseases of the Conjunctiva — MCQs

Diseases of the Conjunctiva — MCQs

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