Diseases of the Conjunctiva — MCQs

Diseases of the Conjunctiva Indian Medical PG Practice Questions and MCQs

Question 141: A recurrent bilateral conjunctivitis occurring with the onset of hot weather in young boys, with symptoms of burning, itching, and lacrimation, and polygonal raised areas in the palpebral conjunctiva, is characteristic of which condition?

A. Trachoma
B. Phlyctenular conjunctivitis
C. Mucopurulent conjunctivitis
D. Vernal conjunctivitis (Correct Answer)

Explanation: ### Explanation The clinical presentation described is a classic case of **Vernal Keratoconjunctivitis (VKC)**, also known as "Spring Catarrh." **Why Option D is Correct:** VKC is a bilateral, recurrent, external ocular inflammation, primarily affecting **young boys** (usually between 5–15 years). It is a **Type I IgE-mediated hypersensitivity** reaction to exogenous allergens (like pollen or dust). * **Seasonal Predilection:** It typically flares up during the onset of **hot weather** (spring/summer). * **Key Symptoms:** Intense **itching** (hallmark), burning, and photophobia. * **Key Sign:** The "polygonal raised areas" refer to **cobblestone papillae** found on the superior palpebral conjunctiva. These are caused by the hyperplasia of subconjunctival lymphoid tissue. **Why Other Options are Incorrect:** * **A. Trachoma:** Caused by *Chlamydia trachomatis* (Serotypes A, B, Ba, C). It presents with follicles and Arlt’s lines, not seasonal itching or cobblestone papillae. * **B. Phlyctenular Conjunctivitis:** A Type IV hypersensitivity reaction to endogenous proteins (most commonly Tubercular protein). It presents as a localized nodule (phlycten) near the limbus, not as generalized polygonal papillae. * **C. Mucopurulent Conjunctivitis:** An acute bacterial infection (e.g., *Staphylococcus aureus*) characterized by redness and discharge, lacking the chronic, recurrent, and seasonal nature of VKC. **High-Yield Clinical Pearls for NEET-PG:** * **Maxwell-Lyons Sign:** Ropey, stringy discharge characteristic of VKC. * **Horner-Trantas Dots:** White limbal spots consisting of eosinophils and epithelial debris (seen in the Limbal variant). * **Shield Ulcer:** A sterile, transverse oval corneal ulcer seen in severe palpebral VKC. * **Treatment:** Mast cell stabilizers (Cromolyn sodium), antihistamines, and topical steroids for acute flares.

Question 142: The histology of pterygium includes which of the following?

A. Elastotic degeneration (Correct Answer)
B. Epithelial inclusion bodies
C. Precancerous changes
D. Squamous metaplasia of the epithelium

Explanation: **Explanation:** **Pterygium** is a wing-shaped, fibrovascular proliferation of the subepithelial conjunctival tissue that encroaches onto the cornea. It is primarily caused by chronic exposure to ultraviolet (UV) light, which leads to the degeneration of the conjunctival stroma. **1. Why "Elastotic Degeneration" is correct:** The hallmark histological feature of a pterygium is **elastotic degeneration** of the subepithelial connective tissue. This involves the breakdown of collagen fibers and their replacement by abnormal, thickened, and tortuous elastic-like fibers (which stain with elastin stains but are not true elastin). This process is often accompanied by hyaline degeneration and increased vascularization. **2. Analysis of Incorrect Options:** * **B. Epithelial inclusion bodies:** These are characteristic of viral infections (like Trachoma) or certain types of conjunctivitis, not the degenerative process of a pterygium. * **C. Precancerous changes:** While a pterygium can occasionally undergo malignant transformation into Ocular Surface Squamous Neoplasia (OSSN), the pterygium itself is a benign degenerative condition, not a precancerous one. * **D. Squamous metaplasia:** While the overlying epithelium may show some thinning or hyperplasia, squamous metaplasia is more characteristic of Vitamin A deficiency (Xerophthalmia) or chronic dry eye states. **High-Yield Clinical Pearls for NEET-PG:** * **Stockers Line:** An iron deposition line seen at the leading edge (head) of a pterygium on the cornea. * **Fuchs’ Islets:** Small, white, precursor patches seen at the advancing edge. * **Treatment of Choice:** Surgical excision with **Limbal Conjunctival Autograft (CAG)** is the gold standard to prevent recurrence. * **Recurrence Prevention:** Mitomycin-C or Beta-irradiation are sometimes used, but CAG is preferred.

Question 143: Which type of neonatal conjunctivitis is most likely to cause neonatal blindness?

A. Neisseria gonorrhoeae (Correct Answer)
B. Chlamydia trachomatis
C. Streptococcus pneumoniae
D. Pseudomonas

Explanation: **Explanation:** **Ophthalmia Neonatorum** (neonatal conjunctivitis) is a critical topic for NEET-PG. While several pathogens cause this condition, **Neisseria gonorrhoeae** is the most dangerous because it is the only common ocular pathogen capable of **penetrating an intact corneal epithelium**. This leads to rapid corneal ulceration, perforation, and endophthalmitis, resulting in permanent blindness if not treated emergently. **Analysis of Options:** * **A. Neisseria gonorrhoeae (Correct):** Characterized by a hyperacute, hyperpurulent discharge occurring 2–5 days after birth. Its ability to cause rapid corneal melting makes it the most sight-threatening etiology. * **B. Chlamydia trachomatis:** This is the **most common** cause of neonatal conjunctivitis worldwide (occurring 5–14 days post-delivery). While it can cause scarring (micropannus), it rarely leads to acute blindness compared to Gonococcus. * **C. Streptococcus pneumoniae:** A common cause of bacterial conjunctivitis in children, but it typically presents as a milder, self-limiting infection without the aggressive corneal involvement seen in Gonorrhea. * **D. Pseudomonas:** While highly virulent and capable of causing rapid corneal destruction in adults (especially contact lens users), it is an uncommon cause of neonatal conjunctivitis compared to the other options. **High-Yield Clinical Pearls for NEET-PG:** 1. **Incubation Periods (Chronology is Key):** * Chemical (Silver nitrate): < 24 hours. * Gonococcal: 2–5 days. * Chlamydial: 5–14 days. * Herpes Simplex (HSV-2): 1–2 weeks. 2. **Prophylaxis:** 1% Silver nitrate (Credé's method) is historical; 0.5% Erythromycin ointment is the current standard. 3. **Treatment:** Systemic Ceftriaxone is mandatory for Gonococcal conjunctivitis to prevent both blindness and systemic dissemination.

Question 144: Conjunctivitis is seen in all except:

A. Cytomegalovirus (CMV) (Correct Answer)
B. Adenovirus
C. Coxsackie A–24
D. Enterovirus 70

Explanation: **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).

Question 145: Which of the following is a significant distinguishing feature of viral conjunctivitis?

A. Significant eye pain
B. Globular purulent discharge
C. Clear discharge (Correct Answer)
D. Eye

Explanation: **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.

Question 146: Which of the following is NOT a cause of tear film deficiency?

A. Infiltrative disease of lacrimal glands
B. Post corneal transplant
C. Systemic Vitamin C deficiency (Correct Answer)
D. Congenital absence of meibomian glands

Explanation: 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.

Question 147: What is the term for a white plaque in the eye caused by vitamin A deficiency?

A. Pink spot
B. White spot
C. Bitot spot (Correct Answer)
D. Herald spot

Explanation: **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.

Question 148: The Schirmer's test is performed to evaluate the function of which gland?

A. Lacrimal gland (Correct Answer)
B. Submandibular gland
C. Parotid gland
D. All of the above

Explanation: **Explanation:** The **Schirmer’s test** is a fundamental diagnostic tool used to measure the quantity of aqueous tear production. It is primarily used to evaluate the secretory function of the **lacrimal gland** (both main and accessory) in patients suspected of having Keratoconjunctivitis Sicca (Dry Eye Syndrome). **Why the Lacrimal Gland is Correct:** The test involves placing a standardized filter paper strip (Whatman filter paper No. 41, 5mm x 35mm) in the lower conjunctival fornix at the junction of the lateral one-third and medial two-thirds. The extent of wetting over a 5-minute period reflects the output of the lacrimal glands. * **Schirmer I:** Measures total secretion (reflex + basal) if done without anesthesia. * **Schirmer II:** Measures reflex secretion specifically by stimulating the nasal mucosa. **Why Other Options are Incorrect:** * **Submandibular and Parotid Glands:** These are major salivary glands located in the oral cavity and neck. While they are affected alongside the lacrimal gland in systemic conditions like **Sjögren’s syndrome** (causing xerostomia and xerophthalmia), the Schirmer’s test specifically measures tear film production, not saliva. Salivary function is typically assessed via sialometry or salivary gland scintigraphy. **High-Yield Clinical Pearls for NEET-PG:** * **Normal Values:** Wetting of **>15 mm** in 5 minutes is normal. * **Mild Dry Eye:** 10–15 mm. * **Moderate Dry Eye:** 5–10 mm. * **Severe Dry Eye:** <5 mm. * **Phenol Red Thread Test:** A faster alternative (15 seconds) that is less irritating than Schirmer’s. * **Rose Bengal Staining:** Used to identify devitalized conjunctival and corneal epithelial cells in dry eye.

Question 149: Lipogranulomatous inflammation is characteristic of which of the following conditions?

A. Fungal infection
B. Tuberculosis
C. Chalazion (Correct Answer)
D. Viral infection

Explanation: **Explanation:** **1. Why Chalazion is Correct:** A **Chalazion** (also known as a Meibomian cyst) is a chronic, non-infectious, **lipogranulomatous inflammation** of the Meibomian glands (modified sebaceous glands). The condition occurs when the gland duct becomes obstructed, leading to the leakage of lipid secretions into the surrounding tarsal stroma. These lipids act as foreign bodies, triggering an inflammatory response characterized by the presence of **multinucleated giant cells**, epithelioid cells, lymphocytes, and plasma cells surrounding the lipid globules. **2. Why Other Options are Incorrect:** * **Fungal Infection:** Typically presents with suppurative inflammation or granulomatous reactions, but lacks the specific lipid-driven (lipogranulomatous) component. * **Tuberculosis:** Characterized by **caseating granulomatous inflammation** (central necrosis with Langhans giant cells), not lipid-driven. * **Viral Infection:** Usually results in a lymphocytic or follicular response rather than a granulomatous one. **3. High-Yield Clinical Pearls for NEET-PG:** * **Location:** More common in the **upper lid** because Meibomian glands are more numerous there (approx. 30-40 in the upper lid vs. 20-30 in the lower lid). * **Clinical Feature:** It is a **painless**, firm, non-tender swelling away from the lid margin (unlike a Stye/Hordeolum Externum, which is painful). * **Complication:** A large chalazion can cause **Against-the-Rule (ATR) astigmatism** due to pressure on the cornea. * **Management:** Small ones may resolve spontaneously; larger ones require **Incision and Curettage (I&C)** via a vertical incision (to avoid damaging adjacent glands). * **Red Flag:** Recurrent chalazion in the same location in elderly patients should be biopsied to rule out **Sebaceous Gland Carcinoma**.

Question 150: Which bacterium does NOT cause ophthalmia neonatorum?

A. Chlamydia
B. Gonococcus
C. Pseudomonas
D. Moraxella (Correct Answer)

Explanation: **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.

Practice by Chapter

Conjunctivitis: Bacterial

Practice Questions

Conjunctivitis: Viral

Practice Questions

Conjunctivitis: Allergic

Practice Questions

Conjunctivitis: Chronic

Practice Questions

Degenerations of Conjunctiva

Practice Questions

Benign Tumors of Conjunctiva

Practice Questions

Malignant Tumors of Conjunctiva

Practice Questions

Conjunctival Manifestations of Systemic Diseases

Practice Questions

Cicatricial Conjunctival Disorders

Practice Questions

Pterygium and Pinguecula

Practice Questions

Conjunctival Trauma

Practice Questions

Subconjunctival Hemorrhage

Practice Questions

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