Diseases of the Conjunctiva Practice Questions

Q: All of the following viruses can involve the eye except?

Echo virus. **Explanation:** The correct answer is **Echo virus**. While many systemic viruses have ocular manifestations, Enteroviruses (like Echo virus) are rarely associated with primary ocular infections. In contrast, the other listed viruses are classic causes of significant ophthalmic disease. * **Echo virus (Correct Answer):** Part of the Enterovirus family, these primarily cause gastrointestinal and respiratory infections, aseptic meningitis, or exanthems. They do not typically target ocular tissues. (Note: **Enterovirus 70** and **Coxsackievirus A24** are exceptions that cause Acute Hemorrhagic Conjunctivitis, but Echo virus specifically is not a standard ocular pathogen). * **Herpes zoster (Incorrect):** Causes **Herpes Zoster Ophthalmicus (HZO)** via the reactivation of the Varicella-zoster virus in the ophthalmic division of the trigeminal nerve. It presents with a painful vesicular rash, pseudodendrites, and uveitis. * **Herpes simplex (Incorrect):** A leading cause of corneal blindness. HSV-1 typically causes **Dendritic Keratitis** (true ulcers with terminal bulbs) and geographic ulcers. * **Adenovirus type 8 (Incorrect):** A major cause of **Epidemic Keratoconjunctivitis (EKC)**. It is highly contagious and characterized by "follicular conjunctivitis" followed by "subepithelial corneal infiltrates." **High-Yield Clinical Pearls for NEET-PG:** 1. **Hutchinson’s Sign:** Vesicles on the tip of the nose in Herpes Zoster indicate involvement of the nasociliary nerve and a high risk of ocular involvement. 2. **Adenovirus Serotypes:** Types 8, 19, and 37 cause EKC; Types 3, 4, and 7 cause Pharyngoconjunctival Fever (PCF). 3. **Dendrites:** HSV causes *true* dendrites (terminal bulbs, stains with Fluorescein); HZ causes *pseudodendrites* (no bulbs, stains poorly).

Q: What is the drug of choice for the treatment of trachoma?

Tetracycline eye ointment. **Explanation:** Trachoma, caused by *Chlamydia trachomatis* (serotypes A, B, Ba, and C), is a leading cause of preventable blindness worldwide. The management follows the WHO-recommended **SAFE strategy** (Surgery, Antibiotics, Facial cleanliness, Environmental improvement). **1. Why Tetracycline is the Correct Answer:** According to the WHO guidelines for the mass treatment of trachoma, **1% Tetracycline eye ointment** applied twice daily for 6 weeks is the traditional drug of choice for topical therapy. It inhibits bacterial protein synthesis by binding to the 30S ribosomal subunit. While oral Azithromycin (single dose) is now the preferred systemic treatment for mass drug administration (MDA), topical Tetracycline remains the standard topical agent, especially in areas where systemic drugs are contraindicated (e.g., pregnancy or infants under 6 months). **2. Why the Other Options are Incorrect:** * **Ciprofloxacin (B):** While a potent fluoroquinolone, it is not the first-line treatment for Chlamydial infections; it is primarily used for bacterial keratitis and conjunctivitis caused by common pyogenic organisms. * **Doxycycline (C):** While oral Doxycycline is effective against Chlamydia, it is not typically used as an **eye ointment** for trachoma. Systemic Doxycycline is an alternative to Azithromycin but is contraindicated in children and pregnant women. **High-Yield Clinical Pearls for NEET-PG:** * **Drug of Choice (Systemic):** Oral Azithromycin (20 mg/kg up to 1g) as a single dose. * **SAFE Strategy:** **S**urgery (for trichiasis), **A**ntibiotics (Azithromycin/Tetracycline), **F**acial cleanliness, **E**nvironmental change. * **Pathognomonic Signs:** Herbert’s pits (limbal follicles) and Arlt’s line (conjunctival scarring). * **Vector:** The common housefly (*Musca sorbens*).

Q: Which of the following conditions is caused by trachoma?

Entropion. **Explanation:** **Trachoma**, caused by *Chlamydia trachomatis* (serotypes A, B, Ba, and C), is a leading cause of preventable blindness worldwide. The pathogenesis follows the "vicious cycle" of repeated infection leading to chronic inflammation. 1. **Why Entropion is Correct:** Chronic inflammation in the palpebral conjunctiva leads to **Arlt’s line** (horizontal scarring). This scarring causes contraction of the tarsal plate, leading to **Cicatricial Entropion** (inward turning of the eyelid). This subsequently causes **Trichiasis** (misdirected eyelashes), where the lashes rub against the cornea, leading to corneal ulceration and opacification. 2. **Why the Other Options are Incorrect:** * **Ectropion:** This is the outward turning of the eyelid. While trachoma causes scarring that pulls the lid inward (entropion), it does not typically cause the lid to turn outward. Ectropion is more commonly age-related (involutional) or due to VII nerve palsy. * **Pinguecula:** This is a degenerative condition of the conjunctiva caused by UV exposure and chronic irritation (dust/wind), characterized by yellowish deposits near the limbus. It is not infectious or related to Chlamydia. **High-Yield Clinical Pearls for NEET-PG:** * **WHO SAFE Strategy:** **S**urgery (for trichiasis), **A**ntibiotics (Azithromycin 20mg/kg single dose), **F**acial cleanliness, **E**nvironmental improvement. * **Herbert’s Pits:** Pathognomonic sign; scarred-down follicles at the limbus. * **Pannus:** Progressive vascularization and infiltration of the cornea, typically starting at the superior limbus. * **McCallan Classification:** Stages Trachoma from I (Incipient) to IV (Healed).

Q: Goblet cells in the conjunctiva are least dense in which region?

Temporal. **Explanation:** The distribution of **goblet cells** in the conjunctiva is non-uniform and follows a specific topographical pattern. Goblet cells are unicellular mucous glands responsible for secreting the **mucin layer** of the tear film, which ensures ocular surface lubrication. **Why Temporal is the correct answer:** Anatomical studies have demonstrated that goblet cell density is **lowest in the temporal quadrant** of the bulbar conjunctiva. The density is highest in the caruncle and the plica semilunaris, followed by the nasal bulbar conjunctiva. This gradient is clinically significant as areas with lower goblet cell density are often more susceptible to drying and early pathological changes in dry eye states. **Analysis of Incorrect Options:** * **A. Nasal:** This is incorrect because the nasal quadrant actually contains the **highest density** of goblet cells in the bulbar conjunctiva. This high concentration is strategically located near the plica semilunaris. * **C. Inferior:** The inferior fornix and bulbar conjunctiva have a moderate density of goblet cells, significantly higher than the temporal region. * **D. None of the above:** Incorrect, as the temporal region is the established anatomical site of least density. **Clinical Pearls for NEET-PG:** 1. **Secretory Product:** Goblet cells secrete **MUC5AC** (gel-forming mucin). 2. **Location:** They are primarily located in the **stratified columnar epithelium** of the conjunctiva. 3. **Clinical Correlation:** A deficiency in goblet cells leads to **mucin deficiency dry eye**, commonly seen in Vitamin A deficiency (Bitot’s spots), Stevens-Johnson Syndrome, and Ocular Cicatricial Pemphigoid. 4. **Diagnostic Test:** **Impression Cytology** is the gold standard for evaluating goblet cell density.

Q: A child presents with a foreign body sensation in both eyes for the past few days. Examination reveals a 'cobblestone appearance' of the tarsal conjunctiva. What is the most likely diagnosis?

Vernal conjunctivitis. **Explanation:** The clinical presentation of a child with bilateral foreign body sensation and a characteristic **'cobblestone appearance'** is a classic description of **Vernal Keratoconjunctivitis (VKC)**, also known as "Spring Catarrh." **1. Why Vernal Conjunctivitis is correct:** VKC is a bilateral, recurrent, external ocular inflammation, primarily affecting young boys in warm climates (Type 1 and Type 4 hypersensitivity). The "cobblestone appearance" refers to **giant papillae** found on the superior tarsal conjunctiva. These are caused by the hypertrophy of conjunctival tissue with a core of capillaries and inflammatory cell infiltration. **2. Why other options are incorrect:** * **Blepharoconjunctivitis:** Typically presents with lid margin crusting, redness, and scales (seborrheic or staphylococcal), but does not feature giant tarsal papillae. * **Phlyctenular conjunctivitis:** Characterized by a small, yellowish-gray nodule (phlycten) near the limbus, usually a hypersensitivity reaction to endogenous toxins (e.g., Tubercular protein). It is not associated with a cobblestone tarsal surface. * **Herpetic keratitis:** Usually unilateral and presents with a dendritic ulcer on the cornea. It is viral in origin and does not cause large tarsal papillae. **3. High-Yield Clinical Pearls for NEET-PG:** * **Trantas Dots:** White, chalky dots at the limbus (composed of eosinophils and epithelial debris) seen in the limbal form of VKC. * **Shield Ulcer:** A sterile, transverse oval corneal ulcer seen in severe cases of VKC. * **Maxwell-Lyons Sign:** A ropy, stringy discharge characteristic of the disease. * **Treatment:** Mast cell stabilizers (Sodium Cromoglycate), antihistamines, and topical steroids for acute exacerbations.

Q: Phlectenular conjunctivitis is classified as which type of hypersensitivity reaction?

Type IV reaction. **Explanation:** **Phlyctenular Keratoconjunctivitis** is a localized, non-infectious inflammatory response of the conjunctiva and cornea. The correct answer is **Type IV (Delayed-type) Hypersensitivity reaction**, as it represents a cell-mediated immune response to an endogenous microbial antigen to which the ocular tissues have become sensitized. * **Why Type IV is correct:** The condition is characterized by the formation of a "phlycten" (a small nodule consisting of a subepithelial infiltration of lymphocytes and macrophages). Historically, the most common inciting antigen was **Tuberculoprotein** (Mycobacterium tuberculosis). In modern clinical practice, the most common cause is **Staphylococcal proteins** (associated with chronic blepharitis). * **Why other options are incorrect:** * **Type I (Immediate):** Mediated by IgE and mast cell degranulation (e.g., Vernal Keratoconjunctivitis). * **Type II (Cytotoxic):** Involves antibodies (IgG/IgM) directed against cell surface antigens (e.g., Ocular Cicatricial Pemphigoid). * **Type III (Immune-complex):** Involves deposition of antigen-antibody complexes (e.g., Stevens-Johnson Syndrome/Scleritis). **High-Yield Clinical Pearls for NEET-PG:** * **Classic Presentation:** A small, pinkish-white nodule near the limbus, surrounded by localized hyperaemia. * **Symptoms:** Intense lacrimation, photophobia, and irritation. * **Fascicular Ulcer:** A characteristic wandering corneal ulcer that carries a leash of blood vessels behind it. * **Treatment:** Topical steroids are the mainstay of treatment to control the inflammatory response, alongside treating the underlying cause (e.g., lid hygiene for Staphylococcal blepharitis or systemic workup for TB).

Q: Schirmer's test is done for:

Dry eye. **Explanation:** **Schirmer’s test** is the gold-standard bedside clinical test used to evaluate **tear production** (aqueous tear deficiency). It is primarily indicated for the diagnosis of **Dry Eye (Keratoconjunctivitis Sicca)**. The test involves placing a specialized filter paper (Whatman filter paper No. 41, 5mm x 35mm) in the lower fornix at the junction of the lateral one-third and medial two-thirds of the eyelid. * **Schirmer I:** Measures total secretion (reflex + basal) without anesthesia. Normal is >15mm in 5 minutes. <5mm is diagnostic of dry eye. * **Schirmer II:** Measures reflex secretion by irritating the nasal mucosa. **Analysis of Incorrect Options:** * **Epiphora:** This refers to the overflow of tears due to anatomical obstruction of the lacrimal drainage system. It is evaluated using the **Jones Dye Test** or Lacrimal Syringing, not Schirmer’s. * **Dacryocystitis:** This is an infection of the lacrimal sac. Diagnosis is clinical (swelling, pain, and regurgitation on pressure over the sac area). * **Myopia:** This is a refractive error where light focuses in front of the retina. It is diagnosed via **Retinoscopy** or subjective refraction. **High-Yield Clinical Pearls for NEET-PG:** * **Basic Secretion Test:** Performed after topical anesthesia to measure only basal secretion (useful in Sjogren’s syndrome). * **Tear Film Break-up Time (TBUT):** Measures tear film stability. Normal is 15–35 seconds; <10 seconds indicates tear film instability. * **Rose Bengal/Lissamine Green Stains:** Used to identify devitalized conjunctival and corneal epithelial cells in severe dry eye. * **Phenol Red Thread Test:** A faster alternative to Schirmer’s (takes 15 seconds).

Q: Which of the following is the likely organism causing ophthalmia neonatorum on the 3rd day of birth?

Neisseria gonorrhoeae. **Explanation:** Ophthalmia neonatorum is defined as conjunctivitis occurring within the first 30 days of life. The most critical factor in identifying the causative organism is the **incubation period** (timing of onset after birth). **1. Why Neisseria gonorrhoeae is correct:** * **Timing:** Gonococcal conjunctivitis typically presents within **2 to 5 days** of birth. Onset on the 3rd day is a classic presentation for this organism. * **Severity:** It is the most hyperacute and vision-threatening form, characterized by profuse purulent discharge, marked chemosis, and a high risk of corneal perforation if not treated urgently with systemic Ceftriaxone. **2. Why the other options are incorrect:** * **Chlamydia trachomatis (B):** This is the most common cause of ophthalmia neonatorum worldwide, but it has a longer incubation period, typically appearing **5 to 14 days** after birth. * **Streptococcus species (C) & Haemophilus influenzae (D):** These are common bacterial causes that usually present between **5 to 10 days** of life. They generally cause a milder, non-specific mucopurulent conjunctivitis compared to Neisseria. **High-Yield Clinical Pearls for NEET-PG:** * **Chemical Conjunctivitis (Silver Nitrate):** Occurs within the **first 24 hours** (usually resolves in 48 hours). * **Herpes Simplex (HSV-2):** Typically presents between **1 to 2 weeks** of life; associated with vesicular skin lesions. * **Prophylaxis:** 0.5% Erythromycin ointment is the standard of care. * **Diagnosis:** Gram stain showing **Gram-negative intracellular diplococci** confirms Neisseria. * **Important Note:** If a neonate has Chlamydial conjunctivitis, always monitor for **Chlamydial pneumonia** (presents with a characteristic "staccato cough").

Q: What is the most common cause of low vision in pterygium?

Astigmatism. **Explanation:** **Pterygium** is a triangular, fibrovascular subepithelial ingrowth of degenerative bulbar conjunctiva onto the cornea. It is most commonly seen in individuals with chronic exposure to UV light. **Why Astigmatism is the Correct Answer:** The most common cause of visual impairment in pterygium is **With-the-Rule (WTR) astigmatism**. As the pterygium grows onto the cornea, it exerts mechanical traction and flattens the horizontal meridian of the cornea. This change in corneal curvature leads to significant astigmatism even before the lesion reaches the pupillary axis. If the pterygium continues to grow and covers the visual axis (pupillary area), it can cause a further profound decrease in vision due to direct obstruction. **Analysis of Incorrect Options:** * **B. Retinal Detachment:** This is a posterior segment pathology involving the neurosensory retina and is unrelated to the surface pathology of a pterygium. * **C. Corneal ulcer and perforation:** While a pterygium can cause localized dryness (Dellen), it rarely leads to spontaneous ulceration or perforation unless complicated by severe secondary infection or trauma. * **D. Myopia:** Pterygium affects the corneal curvature (astigmatism) rather than the axial length of the eye or the overall refractive power in a way that induces simple myopia. **High-Yield Clinical Pearls for NEET-PG:** * **Stocking’s Line:** An iron deposition line seen on the corneal epithelium anterior to the head of the pterygium (indicates stability). * **Fuchs’ Flecks:** Small greyish-white opacities seen at the advancing edge. * **Surgical Gold Standard:** Wide excision with **Limbal Conjunctival Autograft (CAG)** is the treatment of choice to minimize recurrence. * **Indication for Surgery:** Visual impairment (astigmatism or pupillary encroachment), cosmetic disfigurement, or restricted ocular motility.

Question 1

All of the following viruses can involve the eye except?

Accepted Answer

Echo virus

Answer

Herpes zoster

Answer

Herpes simplex

Answer

Adenovirus type 8

Question 2

What is the drug of choice for the treatment of trachoma?

Accepted Answer

Tetracycline eye ointment

Answer

Ciprofloxacin eye ointment

Answer

Doxycycline eye ointment

Answer

None of the above

Question 3

Which of the following conditions is caused by trachoma?

Accepted Answer

Entropion

Answer

Ectropion

Answer

Pinguecula

Answer

All of the above

Question 4

Goblet cells in the conjunctiva are least dense in which region?

Accepted Answer

Temporal

Answer

Nasal

Answer

Inferior

Answer

None of the above

Question 5

A child presents with a foreign body sensation in both eyes for the past few days. Examination reveals a 'cobblestone appearance' of the tarsal conjunctiva. What is the most likely diagnosis?

Accepted Answer

Vernal conjunctivitis

Answer

Blepharoconjunctivitis

Answer

Phlyctenular conjunctivitis

Answer

Herpetic keratitis

Question 6

Phlectenular conjunctivitis is classified as which type of hypersensitivity reaction?

Accepted Answer

Type IV reaction

Answer

Type I reaction

Answer

Type II reaction

Answer

Type III reaction

Question 7

Schirmer's test is done for:

Accepted Answer

Dry eye

Answer

Epiphora

Answer

Dacryocystitis

Answer

Myopia

Question 8

Which of the following is true regarding pterygium?

Accepted Answer

Occurs in the interpalpebral fissure, mostly on the nasal side.

Answer

Dual pterygium is located superiorly and inferiorly.

Answer

It is infective in etiology.

Answer

It is not associated with UV radiation.

Question 9

Which of the following is the likely organism causing ophthalmia neonatorum on the 3rd day of birth?

Accepted Answer

Neisseria gonorrhoeae

Answer

Chlamydia trachomatis

Answer

Streptococcus species

Answer

Haemophilus influenzae

Question 10

What is the most common cause of low vision in pterygium?

Accepted Answer

Astigmatism

Answer

Retinal Detachment

Answer

Corneal ulcer and perforation

Answer

Myopia

Diseases of the Conjunctiva — MCQs

Diseases of the Conjunctiva — MCQs

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