Diseases of the Conjunctiva Practice Questions

Q: In pterygium, which layer of the cornea is most commonly involved?

Bowman's layer. ### Explanation **Correct Answer: C. Bowman’s layer** **Mechanism and Pathophysiology:** A pterygium is a triangular, fibrovascular proliferation of the subconjunctival tissue that encroaches onto the cornea. The hallmark of its progression is the **destruction of Bowman’s layer**. The pathological process involves elastotic degeneration of the collagen fibers. As the pterygium advances, it invades and replaces the superficial stroma and Bowman's membrane, which is why surgical excision often leaves a permanent corneal scar at the site. **Analysis of Incorrect Options:** * **A. Epithelium:** While the epithelium covers the pterygium, it is not the primary site of structural involvement or destruction. The pathology originates beneath the epithelium. * **B. Endothelium:** This is the innermost layer of the cornea. Pterygium is a superficial ocular surface disorder and does not extend to the deep posterior layers. * **D. Descemet’s membrane:** Similar to the endothelium, this is a deep layer. Pterygium is limited to the anterior corneal layers (Epithelium, Bowman’s, and superficial Stroma). **Clinical Pearls for NEET-PG:** * **Stocker’s Line:** An iron deposit (hemosiderin) seen on the corneal epithelium at the leading edge (head) of a stable pterygium. * **Fuchs’ Flecks:** Small, greyish-white opacities seen at the advancing edge, representing precursors to progression. * **Etiology:** Strongly associated with chronic **UV-B exposure** and dry, dusty environments. * **Treatment of Choice:** Surgical excision with **Limbal Conjunctival Autograft (CAG)** is the gold standard to minimize recurrence. * **Recurrence:** The most common complication after simple "bare sclera" excision. Mitomycin-C is sometimes used as an adjuvant to prevent this.

Q: What is the most common cause of neonatal conjunctivitis?

Chlamydia. **Explanation:** **Ophthalmia Neonatorum** (neonatal conjunctivitis) is defined as any discharge or inflammation of the conjunctiva occurring within the first month of life. **Why Chlamydia is Correct:** * **Chlamydia trachomatis (Serotypes D-K)** is currently the **most common infectious cause** of neonatal conjunctivitis worldwide. * It typically presents **5 to 14 days** after birth. * The clinical presentation ranges from mild hyperemia to severe papillary conjunctivitis with pseudomembrane formation. Because neonates lack lymphoid tissue in the conjunctiva at birth, follicles are not seen (unlike in adults). **Analysis of Incorrect Options:** * **Chemical irritation:** Historically common due to Silver Nitrate (Credé’s prophylaxis), it appears within the **first 24 hours** and resolves spontaneously. It is the most common cause in the first day of life, but not overall. * **Gonococcus (Neisseria gonorrhoeae):** This is the **most hyperacute and vision-threatening** cause, appearing **2 to 5 days** after birth. It causes profuse purulent discharge and can penetrate an intact corneal epithelium. * **Herpes simplex (HSV-2):** A rare cause appearing **1 to 2 weeks** after birth, typically associated with vesicular skin lesions and dendritic keratitis. **High-Yield Clinical Pearls for NEET-PG:** 1. **Timeline is Key:** Chemical (24 hrs) → Gonococcal (2–5 days) → Chlamydia (5–14 days) → HSV (1–2 weeks). 2. **Treatment of Choice:** For Chlamydia, **Oral Erythromycin** (50 mg/kg/day for 14 days) is mandatory to treat the ocular infection and prevent Chlamydial pneumonia. 3. **Diagnosis:** Giemsa stain showing **Halberstaedter-Prowazek (HP) inclusion bodies** is characteristic of Chlamydia.

Q: A chronic alcoholic complains of congestion around the lateral canthus and burning sensation with discomfort of the eyes. What is the probable diagnosis?

Angular conjunctivitis. ### Explanation **Correct Answer: C. Angular conjunctivitis** **Medical Concept:** Angular conjunctivitis is characterized by inflammation specifically localized to the **angles of the eye** (lateral more common than medial canthus). It is classically caused by **Morax-Axenfeld bacillus** (*Moraxella lacunata*). The bacteria produce a proteolytic enzyme (protease) that macerates the skin and conjunctiva at the canthi. The association with **chronic alcoholism** is a high-yield clinical pointer. Alcoholics often suffer from **Pyridoxine (Vitamin B6) deficiency**, which predisposes the ocular epithelium to infection by *Moraxella*. The clinical presentation typically involves redness, excoriation of the skin at the outer canthus, and a "burning" sensation. **Why other options are incorrect:** * **Adenoviral conjunctivitis:** Typically presents with acute onset, watery discharge, and preauricular lymphadenopathy. It is usually diffuse rather than localized to the canthus. * **Apollo Disease (Acute Hemorrhagic Conjunctivitis):** Caused by Enterovirus 70 or Coxsackievirus A24. It presents with sudden onset, painful swelling, and characteristic subconjunctival hemorrhages. * **Trachoma:** Caused by *Chlamydia trachomatis* (Serotypes A, B, Ba, C). It primarily affects the superior palpebral conjunctiva, leading to follicles, Herbert’s pits, and eventual scarring (Arlt’s line). **High-Yield Clinical Pearls for NEET-PG:** * **Causative Organisms:** *Moraxella lacunata* (most common) and *Staphylococcus aureus*. * **Deficiency Link:** Often associated with **Vitamin B6 (Pyridoxine)** or **Zinc** deficiency. * **Treatment:** Topical **Zinc-based eye drops** (Zinc inhibits the proteolytic enzyme produced by Moraxella) and Oxytetracycline/Erythromycin ointment. * **Differential Diagnosis:** Always rule out **Blepharitis**, which involves the entire lid margin rather than just the angles.

Q: Which of the following viruses does not cause conjunctivitis?

CMV. **Explanation:** The correct answer is **A. CMV (Cytomegalovirus)**. **1. Why CMV is the correct answer:** While CMV is a member of the Herpesviridae family, it is primarily a **retinotropic** virus. In immunocompromised individuals (especially those with HIV/AIDS and CD4 counts <50 cells/µl), it causes **CMV Retinitis**, characterized by the classic "pizza-pie" or "cheese and ketchup" fundus appearance. CMV does not typically involve the conjunctiva or cause conjunctivitis. **2. Analysis of Incorrect Options:** * **Adenovirus (Option B):** The most common cause of viral conjunctivitis. It causes **Pharyngoconjunctival Fever (PCF)** (Serotypes 3, 4, 7) and **Epidemic Keratoconjunctivitis (EKC)** (Serotypes 8, 19, 37). * **Herpes Simplex Virus (Option C):** HSV-1 can cause primary blepharoconjunctivitis, typically presenting with unilateral follicular conjunctivitis and characteristic vesicular lesions on the lids. * **Picornavirus (Option D):** Specifically, **Enterovirus 70** and **Coxsackievirus A24** are the causative agents of **Acute Hemorrhagic Conjunctivitis (AHC)**, characterized by rapid onset, subconjunctival hemorrhages, and lid edema. **High-Yield Clinical Pearls for NEET-PG:** * **Follicular response:** The hallmark of most viral conjunctivitis (except CMV). * **Preauricular lymphadenopathy:** A key clinical sign of viral conjunctivitis (especially Adenovirus). * **Hutchinson’s Sign:** Vesicles on the tip of the nose indicating Herpes Zoster Ophthalmicus (Nasociliary nerve involvement), which carries a high risk of ocular complications. * **MC cause of Ophthalmia Neonatorum:** *Chlamydia trachomatis* (overall), but *N. gonorrhoeae* is the most hyperacute/destructive.

Q: Horner Trantas nodules are seen in:

Vernal conjunctivitis. **Explanation:** **Vernal Keratoconjunctivitis (VKC)**, also known as "Spring Catarrh," is a bilateral, recurrent, external ocular inflammation primarily affecting young males in hot, dry climates. It is a Type I and Type IV hypersensitivity reaction. **Why the correct answer is right:** **Horner-Trantas Nodules** are a hallmark clinical feature of the **Limbal variant** of VKC. These are small, white, elevated gelatinous dots found at the limbus. Pathologically, they consist of collections of **eosinophils and epithelial debris**. Their presence indicates active disease. In the Palpebral variant, the characteristic finding is "cobblestone" or giant papillae on the superior tarsal conjunctiva. **Why the incorrect options are wrong:** * **Blepharoconjunctivitis:** This involves inflammation of the eyelid margins and conjunctiva, typically presenting with crusting, redness, and telangiectasia, but does not feature limbal eosinophilic nodules. * **Phlyctenular conjunctivitis:** This is a Type IV hypersensitivity to endogenous antigens (like *M. tuberculosis* or *Staphylococcus*). It presents with a **Phlycten**—a small, pinkish-white nodule near the limbus that ulcerates—but it is not composed of eosinophils. * **Herpetic keratitis:** Caused by HSV, this typically presents with dendritic ulcers (epithelial) or disciform edema (stromal) and decreased corneal sensations, rather than allergic nodules. **High-Yield Clinical Pearls for NEET-PG:** * **Maxwell-Lyons Sign:** A ropey, tenacious discharge characteristic of VKC. * **Shield Ulcer:** A sterile, transverse oval ulcer in the upper cornea seen in severe VKC. * **Treatment:** Topical mast cell stabilizers (Olopatadine) are the mainstay; topical steroids are used for acute exacerbations. * **Histology:** Look for increased eosinophils, mast cells, and plasma cells in the conjunctiva.

Q: Acute hemorrhagic conjunctivitis is seen with which of the following?

Adenovirus. **Explanation:** **Acute Hemorrhagic Conjunctivitis (AHC)** is a highly contagious, self-limiting viral infection characterized by sudden onset of ocular pain, lid edema, and prominent subconjunctival hemorrhages. 1. **Why Adenovirus is Correct:** Adenoviruses are the most common cause of viral conjunctivitis. Specifically, **Adenovirus Serotypes 7 and 11** are known to cause AHC. However, the most frequent global causes of AHC are **Enterovirus 70** and **Coxsackievirus A24**. In the context of the given options, Adenovirus is the only viral pathogen listed and is a well-documented cause of hemorrhagic ocular presentations (such as in Epidemic Keratoconjunctivitis). 2. **Why Other Options are Incorrect:** * **Staphylococcal (B):** Typically causes acute mucopurulent conjunctivitis. It is characterized by crusting of lids and yellow discharge rather than frank subconjunctival hemorrhage. * **Pneumococcus (C) & Hemophilus (D):** These are common causes of bacterial conjunctivitis in children. While they can occasionally cause petechial hemorrhages, they primarily present with purulent discharge and "pink eye" symptoms, not the explosive, widespread hemorrhagic clinical picture seen in AHC. **High-Yield Clinical Pearls for NEET-PG:** * **Epidemic Keratoconjunctivitis (EKC):** Caused by Adenovirus serotypes **8, 19, and 37**. It is characterized by "pseudomembranes" and subepithelial corneal infiltrates. * **Pharyngoconjunctival Fever (PCF):** Caused by Adenovirus serotypes **3, 4, and 7**. It presents with the triad of fever, pharyngitis, and follicular conjunctivitis. * **AHC Key Feature:** The incubation period is very short (12–48 hours), and it often occurs in large-scale epidemics.

Q: Herpes pits are diagnostic of which condition?

Chlamydial infection. **Explanation:** **Herbert’s pits** (often misspelled or misheard as "Herpes pits") are a pathognomonic clinical feature of **Trachoma**, which is caused by *Chlamydia trachomatis* (Serotypes A, B, Ba, and C). ### Why Chlamydial Infection is Correct: In the active stage of Trachoma, lymphoid follicles form at the upper limbus. As these follicles heal and regress, they leave behind characteristic shallow, circular, pigmented depressions in the limbal area. These cicatricial depressions are known as **Herbert’s pits**. Their presence is diagnostic of past or chronic chlamydial infection. ### Why Other Options are Incorrect: * **Buphthalmos:** This refers to an enlarged eyeball due to congenital glaucoma. It is characterized by Haab’s striae (breaks in Descemet’s membrane), not limbal pits. * **HSV Infection:** Herpes Simplex Virus typically causes dendritic or geographic ulcers on the cornea. While it can cause follicular conjunctivitis, it does not result in Herbert’s pits. * **Vernal Catarrh (VKC):** This allergic condition presents with "cobblestone" papillae on the palpebral conjunctiva and **Trantas dots** (white limbal spots consisting of eosinophils), but not permanent cicatricial pits. ### NEET-PG High-Yield Pearls for Trachoma: * **Arlt’s Line:** A horizontal scar on the upper palpebral conjunctiva (junction of anterior 1/3rd and posterior 2/3rd). * **WHO Classification (FISTO):** **F**ollicles, **I**ntense inflammation, **S**carring, **T**richiasis, **O**pacity. * **SAFE Strategy:** **S**urgery, **A**ntibiotics (Azithromycin is the drug of choice), **F**acial cleanliness, **E**nvironmental improvement. * **Vector:** The common housefly (*Musca sorbens*).

Q: Which of the following may present as a bluish red nodule resembling conjunctival hemorrhage?

Kaposi sarcoma. **Explanation:** **Kaposi Sarcoma (KS)** is a vascular neoplasm caused by Human Herpesvirus 8 (HHV-8), most commonly seen in patients with HIV/AIDS. In the eye, it typically involves the conjunctiva (usually the inferior fornix). It presents as a **bright red or bluish-red, highly vascularized subconjunctival mass**. Because of its intense vascularity and color, it is frequently mistaken for a chronic subconjunctival hemorrhage. However, unlike a hemorrhage, it does not resolve over time and may appear as a fleshy, elevated nodule. **Why the other options are incorrect:** * **Ciliary Staphyloma:** This is a thinning of the sclera with incarceration of uveal tissue. While it appears dark blue/black, it is located over the ciliary body (behind the limbus) and represents a structural defect of the globe rather than a vascular nodular mass. * **Lymphoma:** Conjunctival lymphoma typically presents as a smooth, painless, **"salmon-pink" or "flesh-colored"** subconjunctival patch or mass. It lacks the intense bluish-red vascular appearance of KS. * **Limbal Dermoid:** This is a congenital choristoma (normal tissue in an abnormal location). It appears as a **whitish-yellow, firm, solid mass** at the limbus, often containing hair follicles or sebaceous glands. **High-Yield Clinical Pearls for NEET-PG:** 1. **HIV Association:** Any patient presenting with a lesion suspicious for Kaposi Sarcoma should be screened for HIV/AIDS. 2. **Differential Diagnosis:** Always differentiate a non-resolving "hemorrhage" from KS or a malignant melanoma. 3. **Treatment:** Management includes Highly Active Antiretroviral Therapy (HAART), local excision, cryotherapy, or radiotherapy. 4. **Salmon-patch appearance:** This is the classic buzzword for Conjunctival Lymphoma.

Question 1

In pterygium, which layer of the cornea is most commonly involved?

Accepted Answer

Bowman's layer

Answer

Epithelium

Answer

Endothelium

Answer

Descemet's membrane

Question 2

What is the most common cause of neonatal conjunctivitis?

Accepted Answer

Chlamydia

Answer

Chemical irritation

Answer

Gonococcus

Answer

Herpes simplex

Question 3

A chronic alcoholic complains of congestion around the lateral canthus and burning sensation with discomfort of the eyes. What is the probable diagnosis?

Accepted Answer

Angular conjunctivitis

Answer

Adenoviral conjunctivitis

Answer

Apollo Disease

Answer

Trachoma

Question 4

Which of the following viruses does not cause conjunctivitis?

Accepted Answer

CMV

Answer

Adenovirus

Answer

Herpes simplex virus

Answer

Picornavirus

Question 5

Horner Trantas nodules are seen in:

Accepted Answer

Vernal conjunctivitis

Answer

Blepharoconjunctivitis

Answer

Phlyctenular conjunctivitis

Answer

Herpetic keratitis

Question 6

Which of the following is true about pterygium?

Accepted Answer

It is common with exposure to UV rays

Answer

It is common on the nasal side

Answer

It is a neoplastic condition

Answer

All pterygia require surgical intervention

Question 7

Acute hemorrhagic conjunctivitis is seen with which of the following?

Accepted Answer

Adenovirus

Answer

Staphylococcal

Answer

Pneumococcus

Answer

Hemophilus

Question 8

What is the primary treatment for Phlyctenular conjunctivitis?

Accepted Answer

Topical steroids

Answer

Systemic steroids

Answer

Antibiotics

Answer

Miotics

Question 9

Herpes pits are diagnostic of which condition?

Accepted Answer

Chlamydial infection

Answer

Buphthalmos

Answer

HSV infection

Answer

Vernal catarrh

Question 10

Which of the following may present as a bluish red nodule resembling conjunctival hemorrhage?

Accepted Answer

Kaposi sarcoma

Answer

Ciliary staphyloma

Answer

Lymphoma

Answer

Limbal dermoid

Diseases of the Conjunctiva — MCQs

Diseases of the Conjunctiva — MCQs

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