Diseases of the Conjunctiva — MCQs

Diseases of the Conjunctiva Indian Medical PG Practice Questions and MCQs

Question 21: Schirmer's test is done for:

A. Epiphora
B. Dacryocystitis
C. Myopia
D. Dry eye (Correct Answer)

Explanation: **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).

Question 22: What is the term for an infection of an eyelash follicle?

A. Stye (Correct Answer)
B. Impetigo
C. Boil
D. Carbuncle

Explanation: ### Explanation **Correct Answer: A. Stye (Hordeolum Externum)** A **stye**, or external hordeolum, is an acute, focal, pyogenic inflammation of the **eyelash follicle** and its associated glands (Glands of Zeis or Moll). It is most commonly caused by *Staphylococcus aureus*. Clinically, it presents as a painful, red, and swollen lump at the eyelid margin, which often points outwards and may develop a yellow pus head around the base of an eyelash. **Why the other options are incorrect:** * **B. Impetigo:** This is a highly contagious superficial bacterial skin infection (usually *Staph. aureus* or *Strep. pyogenes*) characterized by "honey-colored crusts." While it can affect the skin of the eyelids, it is not an infection of the hair follicle itself. * **C. Boil (Furuncle):** A boil is a deep infection of a hair follicle (folliculitis) that involves the dermis and subcutaneous tissue, typically occurring on the trunk, face, or neck. While a stye is technically a "small boil" of the eyelid, the specific anatomical term for the eyelash follicle infection is a stye. * **D. Carbuncle:** This is a cluster of connected furuncles (boils) that form a multi-headed inflammatory mass with deeper suppuration. It is much larger and more severe than a stye. **High-Yield Clinical Pearls for NEET-PG:** * **Internal Hordeolum:** Infection of the **Meibomian glands**. It points toward the conjunctival side (tarsal plate) rather than the skin. * **Chalazion:** A **painless**, chronic granulomatous inflammation of the Meibomian gland (not an acute infection). * **Treatment:** Most styes are self-limiting. Management includes warm compresses (to aid drainage), topical antibiotic ointments, and epilation of the involved eyelash to facilitate pus discharge.

Question 23: Which of the following is true regarding pterygium?

A. Occurs in the interpalpebral fissure, mostly on the nasal side. (Correct Answer)
B. Dual pterygium is located superiorly and inferiorly.
C. It is infective in etiology.
D. It is not associated with UV radiation.

Explanation: **Explanation:** **Pterygium** is a triangular, fibrovascular subepithelial ingrowth of degenerative bulbar conjunctiva onto the cornea. 1. **Why Option A is Correct:** Pterygium characteristically occurs in the **interpalpebral fissure** (the area between the eyelids). It is most commonly found on the **nasal side**. This is attributed to the reflection of light from the side of the nose onto the nasal limbus and the fact that the nasal conjunctiva is more exposed to dust and wind. 2. **Why Other Options are Incorrect:** * **Option B:** "Double pterygium" refers to the presence of growth on both the **nasal and temporal** sides of the same eye, not superiorly/inferiorly. * **Option C:** The etiology is **degenerative**, not infective. It involves elastotic degeneration of collagen fibers (Stockers line may be seen at the leading edge). * **Option D:** Chronic exposure to **UV radiation** (specifically UV-B) is the primary risk factor. It is common in people living in the "Pterygium Belt" (tropical climates) and those with outdoor occupations. **High-Yield Clinical Pearls for NEET-PG:** * **Pathology:** Characterized by **Elastotic Degeneration**. * **Stocker’s Line:** An iron deposition line seen on the corneal epithelium anterior to the head of the pterygium (indicates stability). * **Astigmatism:** Pterygium typically causes **with-the-rule (WTR) astigmatism** due to flattening of the horizontal meridian. * **Treatment of Choice:** Surgical excision with **Limbal Conjunctival Autograft (CAG)** is the gold standard to prevent recurrence. Fibrin glue is preferred over sutures for graft fixation.

Question 24: Which of the following is the likely organism causing ophthalmia neonatorum on the 3rd day of birth?

A. Neisseria gonorrhoeae (Correct Answer)
B. Chlamydia trachomatis
C. Streptococcus species
D. Haemophilus influenzae

Explanation: **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").

Question 25: Pterygium causes visual disturbances due to which of the following?

A. Astigmatism (Correct Answer)
B. Myopia
C. Hypermetropia
D. Keratoconus

Explanation: **Explanation:** A **Pterygium** is a triangular, fibrovascular proliferation of the subconjunctival tissue that encroaches onto the cornea. It causes visual disturbances primarily through two mechanisms: 1. **Astigmatism (Correct Answer):** As the pterygium grows onto the cornea, it exerts mechanical traction and flattens the horizontal meridian of the cornea. This induces **With-the-Rule (WTR) astigmatism**. Additionally, the pooling of the tear film at the advancing edge of the pterygium can further alter the corneal curvature. 2. **Visual Axis Obstruction:** If left untreated, the pterygium may grow centrally and cover the pupillary area, directly blocking the light path. **Why other options are incorrect:** * **Myopia & Hypermetropia:** These are axial or refractive errors primarily related to the length of the eyeball or the resting power of the lens. While a pterygium changes the corneal shape, it specifically causes an irregular or meridional change (astigmatism) rather than a uniform spherical shift. * **Keratoconus:** This is a non-inflammatory ectatic dystrophy characterized by progressive thinning and cone-like bulging of the cornea. While both involve corneal distortion, their etiologies are entirely distinct. **High-Yield Clinical Pearls for NEET-PG:** * **Stocker’s Line:** An iron deposition line seen on the corneal epithelium at the leading edge (head) of a stable pterygium. * **Indication for Surgery:** The most common indication is cosmetic disfigurement, followed by visual impairment (astigmatism or axis encroachment) and restricted ocular motility. * **Surgical Gold Standard:** Excision with **Limbal Conjunctival Autograft (CAG)** is the treatment of choice to minimize the high recurrence rate. * **Prevalence:** More common in the "Pterygium Belt" (tropical regions) due to chronic UV light exposure.

Question 26: What type of epithelium lines the conjunctiva?

A. Pseudostratified
B. Stratified columnar
C. Stratified non-keratinized squamous (Correct Answer)
D. Transitional

Explanation: **Explanation:** The conjunctiva is a thin, translucent mucous membrane. Its primary histological structure is **stratified non-keratinized squamous epithelium**, though the number of layers and specific cell morphology vary across its different regions (palpebral, bulbar, and forniceal). **Why Option C is Correct:** The conjunctiva must provide a protective barrier while remaining moist and flexible to allow for smooth ocular movement. A **stratified non-keratinized squamous** arrangement provides the necessary durability to withstand the friction of blinking without the dryness associated with keratinization (found in skin). Interspersed within this epithelium are **Goblet cells**, which secrete mucin—a critical component of the tear film. **Why Other Options are Incorrect:** * **A. Pseudostratified:** This is characteristic of the respiratory tract (e.g., trachea). While the lacrimal sac and nasolacrimal duct have pseudostratified columnar epithelium, the conjunctiva does not. * **B. Stratified columnar:** While certain parts of the conjunctiva (like the fornix) may appear columnar or cuboidal in the superficial layers, the definitive classification for the conjunctiva as a whole in standard ophthalmic histology is stratified squamous. * **D. Transitional:** This is unique to the urinary tract (urothelium), designed for significant stretching and distension. **High-Yield Clinical Pearls for NEET-PG:** * **Goblet Cells:** Most dense in the **inferonasal quadrant** and the **fornices**. Their loss leads to "Dry Eye" (e.g., in Vitamin A deficiency or Stevens-Johnson Syndrome). * **Bitot’s Spots:** Represent keratinization of the normally non-keratinized conjunctival epithelium due to Vitamin A deficiency. * **Adenoid Layer:** The substantia propria contains a lymphoid (adenoid) layer that is not present at birth but develops at **3–4 months** of age. This explains why follicular conjunctivitis is not seen in newborns.

Question 27: Subconjunctival hemorrhage can occur in all of the following conditions except?

A. Passive venous congestion
B. Peusis
C. Trauma
D. High intraocular tension (Correct Answer)

Explanation: **Explanation:** Subconjunctival hemorrhage (SCH) occurs when a small blood vessel under the conjunctiva ruptures, leading to the accumulation of blood in the potential space between the conjunctiva and the episclera. **Why High Intraocular Tension is the Correct Answer:** High intraocular tension (Glaucoma) refers to the pressure **inside** the eyeball (intraocular). Subconjunctival vessels are located on the **outside** of the globe (extraocular). While high intraocular pressure can cause corneal edema or ciliary congestion, it does not cause the rupture of superficial conjunctival vessels. Therefore, it is not a cause of SCH. **Analysis of Incorrect Options:** * **Passive Venous Congestion:** Any condition that increases venous pressure (e.g., coughing, sneezing, vomiting, or strangulation) can cause the fragile conjunctival capillaries to rupture due to back-pressure. * **Pertussis (Whooping Cough):** This is a classic cause of SCH in children. The violent, paroxysmal coughing fits lead to a sudden spike in venous pressure (Valsalva-like maneuver), causing mechanical rupture of the vessels. * **Trauma:** This is the most common cause of SCH. Direct blunt trauma or even minor eye rubbing can cause vessel wall disruption. In cases of head injury, SCH without a posterior limit may indicate a base of skull fracture. **NEET-PG High-Yield Pearls:** * **Appearance:** SCH is typically asymptomatic, bright red, and has a sharp anterior limit but may lack a posterior limit in orbital fractures. * **Management:** It is a self-limiting condition. Blood usually reabsorbs within 7–14 days without treatment. * **Systemic Associations:** Recurrent or bilateral SCH should prompt an investigation into systemic hypertension or bleeding diathesis (e.g., hemophilia, anticoagulant use).

Question 28: What is the most common cause of low vision in pterygium?

A. Astigmatism (Correct Answer)
B. Retinal Detachment
C. Corneal ulcer and perforation
D. Myopia

Explanation: **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 29: Giant papillary conjunctivitis is most commonly caused by?

A. Contact lens wear (Correct Answer)
B. Trichiasis
C. LASIK surgery
D. L.ASEK surgery

Explanation: **Explanation:** **Giant Papillary Conjunctivitis (GPC)** is a chronic inflammatory condition of the superior palpebral conjunctiva characterized by the formation of large papillae (greater than 1 mm in diameter). **1. Why Contact Lens Wear is Correct:** The most common cause of GPC is **contact lens wear**, particularly soft contact lenses. The pathogenesis is multifactorial, involving both **mechanical irritation** (the constant rubbing of the eyelid over the lens edge) and a **Type I and Type IV hypersensitivity reaction** to protein deposits or preservatives on the lens surface. This leads to the characteristic "cobblestone" appearance of the tarsal conjunctiva. **2. Analysis of Incorrect Options:** * **Trichiasis:** While this involves mechanical irritation of the cornea and bulbar conjunctiva by misdirected eyelashes, it typically causes punctate epithelial erosions or corneal ulcers, not the specific giant papillary response of the tarsal conjunctiva. * **LASIK/LASEK Surgery:** These are refractive surgeries involving the cornea. While they may cause transient dry eye or mild papillary changes due to postoperative drops, they are not primary or common causes of GPC. **3. High-Yield Clinical Pearls for NEET-PG:** * **Definition of "Giant":** Papillae must be **>1 mm** in diameter to be classified as GPC. * **Other Causes:** Ocular prostheses, exposed sutures (nylon), and scleral buckles. * **Clinical Features:** Itching, mucoid discharge, and "contact lens intolerance" (the patient can no longer wear lenses comfortably). * **Management:** The first step is the cessation of contact lens wear, followed by topical mast cell stabilizers (e.g., Cromolyn sodium) or antihistamines. Switching to daily disposables or rigid gas permeable (RGP) lenses may prevent recurrence. * **Differential Diagnosis:** Must be distinguished from **Vernal Keratoconjunctivitis (VKC)**, which also presents with giant papillae but is typically seasonal, bilateral, and occurs in young boys.

Question 30: Trantas spots and Herbe's pits are seen in which of the following conditions?

A. Trachoma (Correct Answer)
B. Following conjunctivitis
C. Spring catarrh
D. Glaucoma

Explanation: **Explanation:** The correct answer is **Trachoma (Option A)**. Trachoma, caused by *Chlamydia trachomatis* (serotypes A, B, Ba, and C), is characterized by specific clinical features depending on the stage of the disease. * **Herbert’s Pits:** These are pathognomonic for Trachoma. They are shallow, oval, or circular depressions found at the superior limbus. They represent the scarred remains of ruptured limbal follicles. * **Trantas Spots:** These are small, white, elevated dots found at the limbus, consisting of eosinophils and epithelial debris. While classically associated with Vernal Keratoconjunctivitis (VKC), they can also be seen in the limbal form of Trachoma during active inflammation. **Analysis of Incorrect Options:** * **Option B (Following conjunctivitis):** General bacterial or viral conjunctivitis does not typically result in permanent limbal scarring (pits) or specific eosinophilic deposits. * **Option C (Spring catarrh/VKC):** While **Trantas spots** are a hallmark of the limbal form of Spring Catarrh (Vernal Keratoconjunctivitis), **Herbert’s pits** are exclusive to Trachoma. Since the question asks for both, Trachoma is the most accurate clinical association. * **Option D (Glaucoma):** This is a disease of the optic nerve and intraocular pressure; it does not involve the formation of conjunctival follicles or limbal pits. **High-Yield Clinical Pearls for NEET-PG:** * **Arlt’s Line:** Horizontal scarring of the superior palpebral conjunctiva (seen in Trachoma). * **SAFE Strategy (WHO):** **S**urgery, **A**ntibiotics (Azithromycin), **F**acial cleanliness, **E**nvironmental improvement. * **Pannus:** Trachomatous pannus is typically superior and progressive. * **Differential:** If the question only mentions "Cobblestone papillae" or "Shield ulcer," think **Spring Catarrh (VKC)**. If it mentions "Herbert's pits," it is always **Trachoma**.

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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