Diseases of the Conjunctiva — MCQs

Diseases of the Conjunctiva Indian Medical PG Practice Questions and MCQs

Question 11: A 67-year-old man complains of a lesion in his left eye. Physical examination reveals a triangular fold of vascularized conjunctiva growing horizontally into the cornea in the shape of an insect wing. Which of the following terms best describes this patient's lesion?

A. Loiasis
B. Onchocerciasis
C. Pinguecula
D. Pterygium (Correct Answer)

Explanation: **Explanation** The correct answer is **Pterygium**. **1. Why Pterygium is correct:** A pterygium is a triangular, wing-shaped (the name is derived from the Greek word *pteryx*, meaning wing) fold of fibrovascular conjunctiva that grows onto the cornea. It typically occurs in the interpalpebral fissure, most commonly on the nasal side. The hallmark of this condition is that it involves a **limbal stem cell deficiency** and invades **Bowman’s layer** of the cornea. The description of a "vascularized conjunctiva growing horizontally" is a classic clinical presentation. **2. Why the other options are incorrect:** * **Pinguecula:** This is a yellowish-white, amorphous deposit of degenerated collagen in the bulbar conjunctiva. Unlike pterygium, it **does not** grow onto the cornea. * **Loiasis:** Caused by the nematode *Loa loa*, this presents as a "Calabar swelling" or a visible subconjunctival worm moving across the eye, rather than a fixed fibrovascular growth. * **Onchocerciasis:** Caused by *Onchocerca volvulus* ("River Blindness"), it primarily affects the cornea (sclerosing keratitis) and posterior segment, but does not present as a wing-shaped conjunctival fold. **3. High-Yield Clinical Pearls for NEET-PG:** * **Etiology:** Strongly associated with chronic UV light exposure (UV-B) and dry, dusty environments. * **Stocker’s Line:** An iron deposition line seen on the corneal epithelium at the leading edge of a pterygium (indicates stability). * **Fuchs' Islets:** Small, white, precursor patches found at the leading edge. * **Management:** Surgical excision is indicated if it threatens the visual axis or causes significant astigmatism. The "Gold Standard" technique to prevent recurrence is **Conjunctival Autograft (CAG)**, often secured with fibrin glue.

Question 12: Epidemics of conjunctivitis are known to occur with which type of infection?

A. Bacterial infections
B. Viral infections
C. None of the above
D. Both of the above (Correct Answer)

Explanation: **Explanation:** Epidemics of conjunctivitis are characterized by a rapid spread of infection within a community, school, or workplace. This occurs primarily due to the highly contagious nature of certain pathogens and their transmission via direct contact, respiratory droplets, or contaminated fomites. **Why the correct answer is "Both of the above":** 1. **Viral Infections:** These are the most common cause of large-scale epidemics. **Adenovirus** is the primary culprit, causing **Epidemic Keratoconjunctivitis (EKC)** (Serotypes 8, 19, 37) and Pharyngoconjunctival Fever (PCF). Another notable cause is Enterovirus 70 and Coxsackievirus A24, which lead to **Acute Hemorrhagic Conjunctivitis (AHC)**. 2. **Bacterial Infections:** While often sporadic, certain bacteria cause seasonal epidemics, especially in children and overcrowded settings. **_Haemophilus influenzae_** (biotype III, formerly *H. aegyptius*) is notorious for causing "Pink Eye" epidemics. In tropical climates, **_Chlamydia trachomatis_** (Serotypes A, B, Ba, C) causes endemic and epidemic Trachoma. **Analysis of Options:** * **Option A & B:** While both are correct individually, selecting only one would be incomplete as both categories of pathogens possess the high infectivity required to trigger an epidemic. * **Option C:** Incorrect, as conjunctivitis is one of the most common infectious disease outbreaks globally. **High-Yield Clinical Pearls for NEET-PG:** * **Adenovirus:** Most common cause of viral conjunctivitis; EKC is associated with "Rule of 8" (Adenovirus type 8, 8-day incubation, 8-day clinical course, followed by subepithelial infiltrates). * **Acute Hemorrhagic Conjunctivitis:** Characterized by rapid onset, subconjunctival hemorrhages, and preauricular lymphadenopathy. * **Transmission:** The most common mode of spread in clinics is via the **tonometer** or the physician’s hands. * **Trachoma:** The leading infectious cause of blindness worldwide; managed by the WHO **SAFE** strategy.

Question 13: Ophthalmia nodosa occurs due to:

A. Leprotic conjunctivitis
B. Syphilitic conjunctivitis
C. Sarcoidosis conjunctivitis
D. Irritation by hair of caterpillar (Correct Answer)

Explanation: **Explanation:** **Ophthalmia Nodosa** is a granulomatous inflammatory reaction of the eye caused by the penetration of **caterpillar hairs** (setae) or certain plant hairs into the ocular tissues. These hairs possess tiny barbs that allow them to migrate deeper into the conjunctiva, cornea, or even the intraocular structures. The condition is characterized by the formation of small, yellowish-grey nodules in the conjunctiva, which are essentially foreign-body granulomas. * **Why Option D is correct:** The term "nodosa" refers to the nodules formed as a defense mechanism against the irritating chemical (thaumetopoein) and mechanical irritation caused by the caterpillar hairs. * **Why Options A, B, and C are incorrect:** While Leprosy, Syphilis, and Sarcoidosis are systemic diseases that can cause granulomatous conjunctivitis or nodules, they are not the causative agents of "Ophthalmia Nodosa." These conditions have distinct systemic markers and different histopathological profiles (e.g., caseating vs. non-caseating granulomas). **High-Yield Clinical Pearls for NEET-PG:** 1. **Clinical Presentation:** Patients often present with sudden onset redness, lacrimation, and a foreign body sensation after exposure to gardens or wooded areas. 2. **Migration:** The hairs can migrate through the cornea into the anterior chamber, causing **iridocyclitis** or even endophthalmitis. 3. **Management:** Immediate treatment involves copious irrigation and surgical removal of visible hairs under a slit lamp. Topical steroids are used to control the granulomatous inflammation. 4. **Histopathology:** Shows a central hair fragment surrounded by palisading macrophages, giant cells, and eosinophils.

Question 14: All are seen in stage 3 Trachoma except?

A. Tarsal epitheliofibrosis
B. Herbe pits
C. Disappearance of Bowman's membrane
D. Trichiasis (Correct Answer)

Explanation: To answer this question, one must understand the **McCallan Classification** of Trachoma, which divides the disease progression into four distinct clinical stages: 1. **Stage I (Incipient Trachoma):** Immature follicles on the upper tarsal conjunctiva. 2. **Stage II (Established Trachoma):** Mature follicles and papillae (Stage IIa: Follicular hypertrophy; Stage IIb: Papillary hypertrophy). 3. **Stage III (Cicatricial Trachoma):** Characterized by **scarring** (Tarsal epitheliofibrosis). 4. **Stage IV (Healed Trachoma):** The disease is inactive, but sequelae (complications) are present. ### Why Trichiasis is the Correct Answer **Trichiasis** is a complication resulting from the cicatricial changes of Stage III. According to the McCallan classification, the presence of sequelae like trichiasis, entropion, or corneal opacity signifies that the patient has moved into **Stage IV (Healed Trachoma)**. While the scarring happens in Stage III, the clinical manifestation of misdirected lashes (trichiasis) is the hallmark of the final, "healed" stage. ### Analysis of Incorrect Options * **A. Tarsal epitheliofibrosis:** This is the hallmark of Stage III. It refers to the scarring of the conjunctiva, often seen as linear scars known as **Arlt’s line**. * **B. Herbert pits:** These are small, circular depressions at the limbus caused by the necrosis and healing of limbal follicles. They are characteristic of the transition into the cicatricial stage (Stage III). * **C. Disappearance of Bowman's membrane:** During the active pannus formation in Trachoma, the infiltration occurs between the epithelium and Bowman’s membrane, eventually leading to the destruction/disappearance of the membrane in the scarred stage (Stage III). ### NEET-PG High-Yield Pearls * **Arlt’s Line:** Horizontal scarring on the upper tarsal conjunctiva (Stage III). * **Herbert Pits:** Pathognomonic for past Trachoma (Stage III/IV). * **WHO "SAFE" Strategy:** **S**urgery (for trichiasis), **A**ntibiotics (Azithromycin), **F**acial cleanliness, **E**nvironmental improvement. * **WHO Grading (FISTO):** **F**ollicles, **I**ntense inflammation, **S**carring, **T**richiasis, **O**pacity. Note that the WHO grading is different from the McCallan classification.

Question 15: Malignant melanoma of conjunctiva is usually of which type?

A. Spindle A type
B. Spindle B type
C. Mixed cell type
D. All of the above (Correct Answer)

Explanation: **Explanation:** Malignant melanoma of the conjunctiva is a rare but potentially life-threatening ocular malignancy. Histologically, it is characterized by a diverse cellular morphology, similar to uveal melanomas but with distinct clinical behavior. **Why "All of the above" is correct:** Conjunctival melanomas are classified based on the Callender classification (originally for uveal melanoma) into three primary cell types: 1. **Spindle A cells:** Slender cells with elongated nuclei and no prominent nucleoli. 2. **Spindle B cells:** Plump cells with distinct nucleoli. 3. **Epithelioid cells:** Large, polygonal cells with abundant cytoplasm and prominent nucleoli (associated with a worse prognosis). 4. **Mixed cell type:** A combination of spindle and epithelioid cells. In clinical practice, most conjunctival melanomas demonstrate a **mixed cell population**. Therefore, all the listed cell types (Spindle A, Spindle B, and Mixed) are recognized histological variants found in these tumors. **Analysis of Options:** * **Options A & B:** While Spindle A and B cells are present, they rarely occur in isolation. * **Option C:** Mixed cell type is common, but it does not exclude the presence of pure spindle variants. * **Option D:** Since all three histological patterns are documented types of conjunctival melanoma, "All of the above" is the most accurate answer. **High-Yield Clinical Pearls for NEET-PG:** * **Origin:** Most conjunctival melanomas (approx. 60-75%) arise from **Primary Acquired Melanosis (PAM)** with atypia. Others arise from pre-existing nevi or *de novo*. * **Most Common Site:** The **bulbar conjunctiva** is the most frequent location. * **Prognostic Factor:** The **thickness (Breslow depth)** of the tumor is the most important predictor of metastasis and survival. * **Spread:** Unlike uveal melanoma (which spreads hematogenously), conjunctival melanoma spreads primarily via **lymphatics** to preauricular and submandibular nodes.

Question 16: Which of the following conditions is caused by trachoma?

A. Entropion (Correct Answer)
B. Ectropion
C. Pinguecula
D. All of the above

Explanation: **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).

Question 17: Goblet cells in the conjunctiva are least dense in which region?

A. Nasal
B. Temporal (Correct Answer)
C. Inferior
D. None of the above

Explanation: **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.

Question 18: 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?

A. Blepharoconjunctivitis
B. Vernal conjunctivitis (Correct Answer)
C. Phlyctenular conjunctivitis
D. Herpetic keratitis

Explanation: **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.

Question 19: Pseudotrichiasis is seen in which of the following conditions?

A. Entropion (Correct Answer)
B. Ectropion
C. Distichiasis
D. Healed membranous conjunctivitis

Explanation: **Explanation:** **Pseudotrichiasis** refers to a condition where the eyelashes are normally directed relative to the lid margin, but they misdirect toward the cornea due to an underlying structural deformity of the eyelid. 1. **Why Entropion is Correct:** In **Entropion**, there is an inward turning of the eyelid margin. Because the entire lid margin rolls inward, the eyelashes (which are otherwise normally implanted) are mechanically forced to rub against the globe. This is the classic definition of pseudotrichiasis. 2. **Analysis of Incorrect Options:** * **Ectropion:** This is the outward turning of the eyelid margin. The lashes point away from the globe, so no corneal irritation occurs. * **Distichiasis:** This is a congenital anomaly where an **extra row of lashes** emerges from the Meibomian gland orifices. This is not pseudotrichiasis, but a distinct anatomical duplication. * **Healed Membranous Conjunctivitis:** This typically leads to **True Trichiasis**. In true trichiasis, the lid margin is in its normal position, but the hair follicles themselves are misdirected due to scarring (cicatrization). **High-Yield Clinical Pearls for NEET-PG:** * **Trichiasis:** Misdirected lashes with a **normal** lid margin (Commonly seen in Trachoma). * **Pseudotrichiasis:** Misdirected lashes with an **inwardly rolled** lid margin (Entropion). * **Distichiasis:** Extra row of lashes (Congenital or metaplasia). * **Madarosis:** Partial or complete loss of eyelashes (Seen in Leprosy, Myxedema, and Chronic Blepharitis). * **Poliosis:** Premature whitening of lashes (Seen in Vogt-Koyanagi-Harada syndrome and Sympathetic Ophthalmitis).

Question 20: Phlectenular conjunctivitis is classified as which type of hypersensitivity reaction?

A. Type I reaction
B. Type II reaction
C. Type III reaction
D. Type IV reaction (Correct Answer)

Explanation: **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).

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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