Diseases of the Conjunctiva — MCQs

Diseases of the Conjunctiva Indian Medical PG Practice Questions and MCQs

Question 61: In the grading of trachoma, trachomatous inflammation - follicular is defined as the presence of?

A. 5 or more follicles in the lower tarsal conjunctiva
B. 3 or more follicles in the lower tarsal conjunctiva
C. 5 or more follicles in the upper tarsal conjunctiva (Correct Answer)
D. 3 or more follicles in the upper tarsal conjunctiva

Explanation: The WHO simplified grading system for Trachoma (FISTO) is a high-yield topic for NEET-PG. This system was designed for field surveys to identify active infection and blinding complications. ### **1. Why Option C is Correct** **Trachomatous inflammation—follicular (TF)** is defined by the presence of **5 or more follicles** in the **upper tarsal conjunctiva**. Each follicle must be at least **0.5 mm** in diameter. The upper tarsal conjunctiva is the specific site of examination because trachoma has a predilection for the superior palpebral conjunctiva, unlike viral or allergic conjunctivitis, which often involve the lower fornix. ### **2. Why Other Options are Incorrect** * **Options A & B:** These are incorrect because the WHO grading specifically evaluates the **upper tarsal conjunctiva**. Follicles in the lower tarsal conjunctiva are non-specific and can be seen in normal children or other types of follicular conjunctivitis. * **Option D:** This is incorrect because the threshold for a "TF" diagnosis is strictly **5 follicles**. Fewer than 5 follicles do not meet the epidemiological criteria for active trachoma intervention. ### **3. Clinical Pearls for NEET-PG (The FISTO Mnemonic)** * **T (TF):** 5+ follicles (≥0.5mm) on the upper tarsal conjunctiva. * **I (TI):** Trachomatous Inflammation—Intense. Pronounced inflammatory thickening of the upper tarsal conjunctiva that obscures more than half of the normal deep tarsal vessels. * **S (TS):** Trachomatous Scarring. Presence of easily visible white fibrous bands (Arlt’s line). * **T (TT):** Trachomatous Trichiasis. At least one eyelash rubbing on the eyeball. * **O (CO):** Corneal Opacity. Easily visible opacity over the pupil. **High-Yield Fact:** The drug of choice for mass prophylaxis in Trachoma is a single dose of **Azithromycin (20mg/kg)**. For the SAFE strategy, "S" stands for Surgery and "A" for Antibiotics.

Question 62: Conjunctival ulceration may suggest which of the following?

A. Embedded foreign body
B. Tuberculosis
C. Syphilis
D. Syphilis (Correct Answer)

Explanation: **Explanation:** Conjunctival ulceration is a relatively rare clinical finding compared to conjunctivitis, and its presence should immediately raise suspicion for specific granulomatous infections or mechanical trauma. **Why Syphilis is the Correct Answer:** Syphilis, caused by *Treponema pallidum*, can manifest in the conjunctiva during both primary and secondary stages. A **primary chancre** typically presents as a painless, indurated ulcer, usually on the palpebral conjunctiva, accompanied by significant regional lymphadenopathy (preauricular or submandibular). This classic presentation of a "granulomatous conjunctival ulcer" makes Syphilis a high-yield diagnosis for this clinical sign. **Analysis of Other Options:** * **Embedded Foreign Body:** While a foreign body can cause a corneal or conjunctival **abrasion** or localized granuloma, it typically does not present as a classic "ulceration" unless secondary infection occurs. * **Tuberculosis (TB):** TB of the conjunctiva usually presents as a chronic granulomatous inflammation, nodules, or "apple-jelly" follicles. While it *can* cause ulceration (Parinaud’s Oculoglandular Syndrome), Syphilis is more traditionally associated with the specific "ulcerative" lesion (chancre) in standard ophthalmic teaching. *(Note: In many clinical contexts, TB is also a differential; however, based on standard MCQ patterns for NEET-PG, Syphilis is the prioritized classic answer for conjunctival ulcers.)* **High-Yield Clinical Pearls for NEET-PG:** 1. **Parinaud’s Oculoglandular Syndrome:** Characterized by unilateral granulomatous conjunctivitis with follicles/ulcers and ipsilateral painful lymphadenopathy. Causes include Cat-scratch disease (most common), Tularemia, TB, and Syphilis. 2. **Primary Chancre:** Always suspect Syphilis in any painless, indurated ulcer of the lid margin or conjunctiva. 3. **Differential Diagnosis of Conjunctival Ulcers:** Syphilis, TB, Tularemia, and Glanders.

Question 63: Pseudopterygium is not typically seen following which of the following conditions or procedures?

A. Eye surgery
B. Injury of the eye
C. Chemical injury of the eye
D. Astigmatism (Correct Answer)

Explanation: ### Explanation **Pseudopterygium** is a fold of bulbar conjunctiva that becomes adherent to the cornea following an inflammatory insult. The underlying medical concept is **cicatrization** (scarring); it occurs when a denuded corneal surface and an adjacent conjunctival injury heal together, causing the conjunctiva to bridge over the limbus. **Why Astigmatism is the correct answer:** Astigmatism is a **refractive error**, not an inflammatory or traumatic process. While a true pterygium or a pseudopterygium can *cause* astigmatism by distorting the corneal curvature, astigmatism itself does not lead to the formation of a pseudopterygium. **Why the other options are incorrect:** * **Eye surgery & Injury (Options A & B):** Any mechanical trauma or surgical procedure (e.g., squint surgery or removal of a growth) that causes a peripheral corneal ulcer or limbal damage can trigger the adhesion of conjunctiva during the healing phase. * **Chemical injury (Option C):** This is a classic cause. Chemical burns lead to extensive ocular surface inflammation and epithelial defects, providing the perfect environment for the conjunctiva to fuse with the cornea. --- ### High-Yield Clinical Pearls for NEET-PG | Feature | True Pterygium | Pseudopterygium | | :--- | :--- | :--- | | **Etiology** | Degenerative (UV light exposure) | Inflammatory (Trauma/Burns) | | **Probe Test** | **Negative** (Cannot pass under) | **Positive** (Can pass under the fold) | | **Location** | Usually horizontal (3 or 9 o'clock) | Any position on the limbus | | **Progression** | Progressive | Stationary (Non-progressive) | | **Age** | Elderly/Adults | Any age (post-injury) | * **The Probe Test** is the most definitive clinical sign to differentiate the two: in pseudopterygium, the conjunctiva is only attached at its apex (the cornea), allowing a probe to pass beneath it at the limbus.

Question 64: Rosettes found at the lid margin are a feature of?

A. Squamous blepharitis
B. Bacterial blepharitis (Correct Answer)
C. Stye
D. Chalazion

Explanation: **Explanation:** **Bacterial Blepharitis** (specifically Chronic Staphylococcal Blepharitis) is characterized by chronic inflammation of the eyelid margins. The hallmark clinical sign is the presence of hard, brittle scales called **"collarettes"** or **"rosettes"** at the base of the eyelashes. These are formed by dried inflammatory secretions and fibrin that encircle the lash like a ring. When these scales are removed, they often reveal small, bleeding ulcers (ulcerative blepharitis), which is a pathognomonic feature of *Staphylococcus aureus* infection. **Analysis of Incorrect Options:** * **Squamous Blepharitis:** This is typically associated with Seborrheic Blepharitis. It presents with greasy, soft scales (scurf) that are easily removed without leaving underlying ulcers. It is often associated with seborrheic dermatitis of the scalp. * **Stye (Hordeolum Externum):** This is an acute, painful, suppurative abscess of the Zeis or Moll glands. It presents as a localized red nodule rather than generalized lid margin rosettes. * **Chalazion:** This is a chronic, non-tender, granulomatous inflammation of the Meibomian glands. It is a localized swelling within the tarsal plate, not an infection of the lash follicles. **Clinical Pearls for NEET-PG:** * **Collarettes/Rosettes:** Think *Staphylococcal Blepharitis*. * **Greasy scales/Scurf:** Think *Seborrheic Blepharitis*. * **Poliosis (whitening of lashes) and Madarosis (loss of lashes):** Common complications of chronic bacterial blepharitis. * **Treatment:** Lid hygiene (warm compresses/scrubs) and topical antibiotic ointments (e.g., Erythromycin or Bacitracin).

Question 65: Normal values of Schirmer-I test are:

A. 5 mm
B. 10 mm
C. 15 mm
D. 15 mm or above (Correct Answer)

Explanation: **Explanation:** The **Schirmer-I test** is a diagnostic tool used to measure tear production, specifically assessing the total tear secretion (both basal and reflex). It is performed using a standardized Whatman filter paper (No. 41), measuring 5 mm x 35 mm, which is placed in the lower conjunctival fornix at the junction of the lateral one-third and medial two-thirds. **1. Why "15 mm or above" is correct:** In a healthy individual with normal lacrimal gland function, the wetting of the filter paper after **5 minutes** should be **15 mm or more**. This value indicates adequate tear production to maintain the ocular surface. **2. Analysis of Incorrect Options:** * **10 mm to 14 mm:** This range is considered "mildly decreased" or borderline. While not always symptomatic, it suggests a potential deficiency in tear production. * **5 mm to 10 mm:** This indicates "moderate" aqueous tear deficiency (Dry Eye/Keratoconjunctivitis Sicca). * **Below 5 mm:** This is diagnostic of "severe" dry eye. **High-Yield Clinical Pearls for NEET-PG:** * **Schirmer-I vs. Schirmer-II:** Schirmer-I measures total secretion (basal + reflex). **Schirmer-II** measures only reflex secretion by irritating the nasal mucosa with a cotton swab (Normal: >15 mm after 2 minutes). * **Basal Secretion Test:** Performed like Schirmer-I but after applying a topical anesthetic (Proparacaine) to eliminate reflex tearing. * **Phenol Red Thread Test:** A faster alternative (15 seconds) that is less irritating than the Schirmer test. * **Tear Film Break-up Time (BUT):** Measures tear film stability. Normal is 15–35 seconds; <10 seconds is abnormal. * **Rose Bengal/Lissamine Green Stains:** Used to identify devitalized conjunctival and corneal cells in severe dry eye.

Question 66: Pharyngoconjunctival fever type of acute follicular conjunctivitis is not caused by which of the following strains of Adenovirus?

A. 3
B. 4
C. 7
D. 8 (Correct Answer)

Explanation: ### Explanation **Pharyngoconjunctival Fever (PCF)** is a highly contagious form of acute follicular conjunctivitis caused by specific serotypes of **Adenovirus**. **1. Why Option D (Serotype 8) is the correct answer:** Adenovirus **Serotype 8** (along with types 19 and 37) is the primary causative agent of **Epidemic Keratoconjunctivitis (EKC)**. EKC is a more severe condition characterized by significant corneal involvement (keratitis) and lacks the systemic symptoms (fever and pharyngitis) seen in PCF. Therefore, Serotype 8 is not associated with PCF. **2. Why the other options are incorrect:** * **Options A, B, and C (Serotypes 3, 4, and 7):** These are the classic strains responsible for PCF. * **Serotype 3** is the most common cause. * **Serotypes 4 and 7** are also frequently implicated in outbreaks, often associated with contaminated swimming pools (hence the name "Swimming Pool Conjunctivitis"). **3. Clinical Pearls for NEET-PG:** * **PCF Triad:** 1. Fever, 2. Pharyngitis (sore throat), 3. Acute follicular conjunctivitis (usually bilateral with preauricular lymphadenopathy). * **Transmission:** Primarily via respiratory droplets or contaminated water in swimming pools. * **Epidemic Keratoconjunctivitis (EKC):** Caused by types **8, 19, and 37**. It is known for the "Rule of 8": caused by Adenovirus 8, 8-day incubation period, and 8-day duration of infectiousness. * **Follicles vs. Papillae:** Remember that Adenoviral infections typically present with **follicles** (pale, rice-grain-like elevations) in the inferior fornix, whereas allergic conditions often present with papillae.

Question 67: Epithelial xerosis of the conjunctiva is caused by?

A. Trachoma
B. Diphtheria
C. Xerophthalmia (Correct Answer)
D. Pemphigus

Explanation: **Explanation:** **Correct Answer: C. Xerophthalmia** Epithelial xerosis is a hallmark of **Vitamin A deficiency (Xerophthalmia)**. In this condition, the conjunctival epithelium undergoes squamous metaplasia, transforming from a non-keratinized stratified columnar epithelium with goblet cells into a **keratinized stratified squamous epithelium**. The loss of mucus-secreting goblet cells leads to dryness, a lack of luster, and the characteristic "dry-skin" appearance of the conjunctiva. This is clinically identified as Stage X1A in the WHO classification. **Analysis of Incorrect Options:** * **Trachoma (A), Diphtheria (B), and Pemphigus (D):** These conditions cause **Parenchymatous xerosis**. Unlike epithelial xerosis, parenchymatous xerosis results from extensive scarring (cicatrization) of the conjunctiva, which destroys the accessory lacrimal glands and occludes the ducts of the main lacrimal gland. * *Trachoma* and *Diphtheria* cause cicatricial scarring post-infection. * *Pemphigus* (specifically Ocular Cicatricial Pemphigoid) is an autoimmune blistering disease leading to symblepharon and severe dry eye. **High-Yield Clinical Pearls for NEET-PG:** * **Bitot’s Spots (Stage X1B):** These are triangular, foamy, silvery-white patches on the bulbar conjunctiva (usually temporal) caused by *Corynebacterium xerosis* gas production on the xerotic epithelium. * **WHO Classification of Xerophthalmia:** * X1A: Conjunctival xerosis * X1B: Bitot’s spots * X2: Corneal xerosis * X3A/X3B: Corneal ulceration/Keratomalacia (<1/3 or >1/3 of cornea) * XS: Corneal scar * XN: Night blindness (earliest clinical symptom) * **Treatment:** Vitamin A (Retinol) 200,000 IU orally on days 0, 1, and 14 (half dose for infants 6–12 months).

Question 68: Most viral infections of the eye present as?

A. Conjunctivitis
B. Keratitis
C. Keratoconjunctivitis (Correct Answer)
D. None of the above

Explanation: **Explanation:** **Why Keratoconjunctivitis is the correct answer:** Most viral infections of the eye, particularly those caused by **Adenovirus** (the most common viral pathogen), do not remain localized to a single tissue. While the infection typically begins in the conjunctiva, the virus frequently involves the corneal epithelium due to the anatomical continuity and shared surface environment. This dual involvement is termed **Keratoconjunctivitis**. For example, Adenovirus causes two major clinical syndromes: **Epidemic Keratoconjunctivitis (EKC)** and **Pharyngoconjunctival Fever (PCF)**, both of which characteristically involve both the cornea and the conjunctiva. **Analysis of Incorrect Options:** * **A. Conjunctivitis:** While viral infections start as conjunctivitis (presenting with watery discharge and follicles), isolated conjunctivitis is less common than combined involvement. In clinical practice, the presence of subepithelial infiltrates (a corneal sign) is a hallmark of progressing viral infection. * **B. Keratitis:** Isolated viral keratitis is rare. Even in Herpes Simplex Virus (HSV) infections, the primary presentation often involves a follicular conjunctival response alongside the characteristic dendritic corneal ulcers. **NEET-PG High-Yield Pearls:** * **Adenovirus Serotypes:** Types 8, 19, and 37 are most commonly associated with **EKC** (more severe, no fever). Types 3, 4, and 7 cause **PCF** (associated with sore throat and fever). * **Clinical Sign:** The presence of **pre-auricular lymphadenopathy** is a classic diagnostic pointer for viral keratoconjunctivitis. * **Follicles vs. Papillae:** Viral infections typically produce a **follicular** reaction (hyperplastic lymphoid tissue) in the inferior fornix, whereas allergic reactions often produce papillae. * **Treatment:** Most viral keratoconjunctivitis is self-limiting; treatment is primarily supportive (cold compresses, artificial tears).

Question 69: Subconjunctival hemorrhage occurs in all of the following conditions EXCEPT:

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

Explanation: **Explanation:** Subconjunctival hemorrhage (SCH) occurs when a small blood vessel under the conjunctiva ruptures, leading to a bright red patch on the sclera. The key to answering this question lies in understanding that SCH is caused by **vascular fragility or sudden changes in venous pressure**, not by the pressure inside the globe itself. **Why "High Intraocular Tension" is the correct answer:** Intraocular tension (IOP) refers to the fluid pressure *inside* the eye (aqueous humor). High IOP (Glaucoma) can cause corneal edema or optic nerve damage, but it does not cause subconjunctival hemorrhage. SCH is an **extraocular** vascular event occurring in the subconjunctival space, which is independent of the internal pressure of the eye. **Analysis of Incorrect Options:** * **Passive Venous Congestion:** Any obstruction to venous return from the head and neck (e.g., tight neckties, thoracic tumors) increases capillary pressure, leading to vessel rupture. * **Pertussis (Whooping Cough):** The violent, paroxysmal coughing fits cause a sudden, massive spike in venous pressure (Valsalva maneuver), which is a classic cause of SCH in children. * **Trauma:** Direct ocular trauma or head injury (e.g., base of skull fracture) can rupture conjunctival vessels. **NEET-PG High-Yield Pearls:** * **Most common cause:** Idiopathic (often occurring during sleep). * **Valsalva Maneuver:** Sneezing, coughing, straining at stool, or lifting heavy weights are frequent triggers. * **Systemic Associations:** Always rule out hypertension and bleeding diathesis (check PT/INR) in recurrent cases. * **Management:** It is a self-limiting condition. Reassurance is the treatment of choice; blood usually resorbs within 7–14 days. * **Clinical Sign:** A key feature of SCH is that the posterior limit of the hemorrhage is usually visible (unlike in a base of skull fracture where the posterior limit is hidden).

Question 70: Which of the following is true about Bitot's spots?

A. Predispose to pterygium.
B. Caused by hyperplasia of goblet cells.
C. Seen with fat malabsorption. (Correct Answer)
D. Most common site is the nasal side of the conjunctiva.

Explanation: **Explanation:** Bitot’s spots are a hallmark clinical sign of **Vitamin A deficiency (Xerophthalmia)**. Vitamin A is a fat-soluble vitamin; therefore, any condition causing **fat malabsorption** (such as Celiac disease, chronic pancreatitis, or biliary obstruction) can lead to secondary Vitamin A deficiency and the subsequent development of these spots. **Analysis of Options:** * **Option C (Correct):** Vitamin A requires bile salts and dietary fat for absorption. Malabsorption syndromes lead to a systemic deficiency, resulting in squamous metaplasia of the conjunctival epithelium. * **Option A:** Bitot’s spots do not predispose to pterygium. Pterygium is primarily associated with chronic UV light exposure and elastotic degeneration. * **Option B:** Bitot’s spots are caused by the **loss (destruction) of goblet cells** and keratinization of the conjunctiva. The "foamy" appearance is due to the accumulation of keratin debris and gas-forming bacilli (*Corynebacterium xerosis*). * **Option D:** The most common site is the **temporal** side of the interpalpebral conjunctiva. While they can occur nasally, the temporal location is more characteristic and usually appears first. **High-Yield Clinical Pearls for NEET-PG:** * **WHO Classification:** Bitot’s spots are classified as **Stage X1B**. * **Appearance:** Triangular, foamy, silvery-white patches that are non-wettable. * **Reversibility:** They are typically reversible with high-dose Vitamin A supplementation. * **First Symptom vs. Sign:** Night blindness (Nyctalopia) is the earliest *symptom* (X1A), while Conjunctival Xerosis is the earliest *sign*.

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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