Diseases of the Conjunctiva Practice Questions

Q: A 4-year-old child develops an infection with Chlamydia trachomatis. How does infection with this organism cause blindness?

Scarring of the cornea. **Explanation:** The correct answer is **D. Scarring of the cornea.** **Pathophysiology:** *Chlamydia trachomatis* (Serotypes A, B, Ba, and C) is the causative agent of **Trachoma**, the leading infectious cause of blindness worldwide. The blindness is not a direct result of the initial infection but a consequence of chronic, recurrent inflammation. 1. Repeated infections lead to severe conjunctival scarring (**Arlt’s line**). 2. This scarring causes the eyelids to turn inward (**Entropion**) and the eyelashes to rub against the globe (**Trichiasis**). 3. Constant mechanical trauma from trichiasis, combined with a deficient tear film, leads to secondary bacterial infections, **corneal ulceration**, and eventually dense **corneal opacification/scarring**, which obstructs vision. **Why other options are incorrect:** * **Option A:** Cataracts are caused by aging, trauma, or metabolic derangements, not by Chlamydial surface infections. * **Options B & C:** Hemorrhage into the chambers (Hyphema or Vitreous hemorrhage) is typically associated with trauma, neovascularization (e.g., Diabetes), or vascular occlusions, rather than the cicatrizing (scarring) process of Trachoma. **NEET-PG High-Yield Pearls:** * **WHO Grading (FISTO):** **F**ollicular, **I**ntense inflammation, **S**carring, **T**richiasis, **O**pacity. * **Herbert’s Pits:** Pathognomonic scarred remains of follicles at the limbus. * **Pannus:** Progressive vascularization of the upper part of the cornea is a classic finding. * **SAFE Strategy:** **S**urgery (for trichiasis), **A**ntibiotics (Azithromycin), **F**acial cleanliness, **E**nvironmental improvement. * **Drug of Choice:** Single dose of oral **Azithromycin** (20 mg/kg).

Q: What is a pterygium?

An inflammatory response. **Explanation:** A **pterygium** is a triangular, fibrovascular subepithelial ingrowth of the bulbar conjunctiva onto the cornea. While traditionally described as a degenerative condition (elastotic degeneration), modern histopathological understanding classifies it as a **chronic inflammatory and proliferative response**. It is triggered by chronic exposure to ultraviolet (UV) light, which leads to the activation of limbal stem cells, the release of inflammatory cytokines, and the upregulation of matrix metalloproteinases (MMPs). This inflammatory cascade drives angiogenesis and fibrovascular proliferation. **Analysis of Options:** * **Option A (Correct):** It is an inflammatory response characterized by the infiltration of mast cells, lymphocytes, and the expression of inflammatory markers (like VEGF and TGF-beta). * **Option B (Incorrect):** While it involves connective tissue changes (elastotic degeneration), it is not classified as a systemic "connective tissue disorder" like Lupus or Scleroderma. * **Option C (Incorrect):** Pterygium is a non-infectious condition; it is caused by environmental factors (UV rays, dust, wind), not pathogens. * **Option D (Incorrect):** Vitamin A deficiency is associated with **Bitot’s spots** and Xerophthalmia, not pterygium. **High-Yield NEET-PG Pearls:** * **Stockers Line:** An iron deposition line seen on the corneal epithelium at the leading edge (head) of the pterygium, indicating stability. * **Fuchs’ Striae:** Small whitish spots seen at the advancing edge. * **Surgical Gold Standard:** Excision with **Limbal Conjunctival Autograft (CAG)** is the treatment of choice to minimize recurrence. * **Location:** Most commonly occurs on the **nasal side** within the interpalpebral fissure.

Q: Which organism commonly causes severe conjunctivitis?

Neisseria. **Explanation:** The severity of bacterial conjunctivitis is categorized based on clinical presentation and the speed of progression. **Neisseria gonorrhoeae** (and occasionally *N. meningitidis*) is the classic cause of **Hyperacute Purulent Conjunctivitis**. **Why Neisseria is correct:** Neisseria species are unique because they possess the ability to penetrate an **intact corneal epithelium**. This leads to a rapid, "hyperacute" onset (within 12–24 hours) characterized by profuse, thick, creamy purulent discharge, severe chemosis, and a high risk of corneal perforation. This clinical urgency distinguishes it from other bacterial causes. **Why the other options are incorrect:** * **Staphylococcus aureus:** This is the most common cause of *chronic* or *acute* bacterial conjunctivitis worldwide. While it causes "sticky eyes" and mucopurulent discharge, it rarely leads to the hyperacute, sight-threatening severity seen with Neisseria. * **Streptococcus pneumoniae:** Typically causes acute hemorrhagic conjunctivitis with petechial subconjunctival hemorrhages, often associated with respiratory infections in children, but it is generally less destructive than Neisseria. * **Haemophilus influenzae:** Commonly causes acute mucopurulent conjunctivitis in children, often occurring in epidemics, but it does not typically present with the hyperacute severity of a gonococcal infection. **High-Yield Clinical Pearls for NEET-PG:** 1. **Treatment:** Hyperacute conjunctivitis requires systemic antibiotics (e.g., IV/IM Ceftriaxone) in addition to topical therapy. 2. **Ophthalmia Neonatorum:** *N. gonorrhoeae* typically appears within **2–5 days** of birth and is the most destructive cause. 3. **Intact Epithelium:** Remember the mnemonic **"NHL"** for organisms that can penetrate intact corneal epithelium: **N**eisseria, **H**aemophilus aegyptius, **L**isteria, and *Corynebacterium diphtheriae*.

Q: Which of the following is FALSE regarding phlyctenular conjunctivitis?

The most common cause is tuberculosis.. **Explanation:** Phlyctenular keratoconjunctivitis is an **endogenous microbial allergic reaction** of the conjunctiva and cornea to a foreign protein. **1. Why Option A is the correct (False) statement:** While **Tuberculosis** was historically the most common cause worldwide, in the modern era and specifically in the context of current medical literature, **Staphylococcal proteins** (associated with chronic blepharitis) are now considered the **most common cause** of phlyctenular conjunctivitis. Tuberculosis remains an important cause in developing countries, but it is no longer the "most common" globally. **2. Analysis of other options:** * **Option B (True):** The classic lesion, a "phlycten" (a pinkish-white nodule), is most commonly located at or near the **limbus**. It can also occur on the bulbar conjunctiva or the cornea. * **Option C (True):** This condition predominantly affects **children and young adults** (usually between 5–15 years of age), often those living in overcrowded or unsanitary conditions. * **Option D (True):** It is a classic example of a **Type IV (Delayed) Hypersensitivity reaction** to bacterial proteins (Staphylococcus, Mycobacterium tuberculosis, Moraxella axenfeldii, etc.). **Clinical Pearls for NEET-PG:** * **Symptoms:** Intense itching, lacrimation, and photophobia (photophobia is severe if the cornea is involved). * **Fascicular Ulcer:** A characteristic "serpiginous" corneal ulcer formed when a limbal phlycten migrates towards the center of the cornea, carrying a leash of blood vessels behind it. * **Treatment:** Topical steroids (to control the allergic reaction) and treatment of the underlying cause (e.g., lid hygiene for blepharitis or systemic workup for TB).

Q: Which of the following are seen in trachoma?

All of the above. Trachoma, caused by **Chlamydia trachomatis (serotypes A, B, Ba, and C)**, is a chronic keratoconjunctivitis characterized by a mixed inflammatory response. It is a leading cause of preventable blindness worldwide. **Explanation of the Correct Answer:** The correct answer is **All of the above** because Trachoma involves both the conjunctiva and the cornea through a specific pathological progression: * **Follicles (Option B):** These are the hallmark of active trachoma, typically seen on the upper tarsal conjunctiva. They represent subepithelial lymphoid aggregations. * **Papillary Hypertrophy (Option A):** This is a non-specific inflammatory response where the conjunctiva becomes red and velvety due to vascular proliferation. In trachoma, papillae often coexist with follicles (predominantly in the upper tarsus). * **Pannus Formation (Option C):** This refers to inflammatory vascularization and infiltration of the superior cornea. It is a classic sign of trachomatous keratitis. **Why other options are not selected individually:** While A, B, and C are all characteristic features, selecting any single one would be incomplete. Trachoma is unique because it presents with a **"Mixed Follicular-Papillary Response"** along with corneal involvement (Pannus). **High-Yield Clinical Pearls for NEET-PG:** * **Arlt’s Line:** Horizontal scarring on the upper tarsal conjunctiva (Stage IV). * **Herbert’s Pits:** Depressions on the limbus resulting from the healing of limbal follicles (Pathognomonic). * **WHO SAFE Strategy:** **S**urgery (for trichiasis), **A**ntibiotics (Azithromycin), **F**acial cleanliness, **E**nvironmental improvement. * **Drug of Choice:** Single dose of oral **Azithromycin** (20 mg/kg). * **Surgical Procedure:** Bilamellar Tarsal Rotation (for entropion/trichiasis).

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

Papilloma virus. **Explanation:** **Acute Hemorrhagic Conjunctivitis (AHC)** is a highly contagious clinical syndrome characterized by sudden onset of painful conjunctival inflammation, lid edema, and pathognomonic subconjunctival hemorrhages. **Why Papilloma Virus is the Correct Answer:** Human Papilloma Virus (HPV) is primarily associated with the formation of **conjunctival papillomas** (benign epithelial tumors). These present as pedunculated or sessile growths rather than an acute inflammatory or hemorrhagic process. It does not cause the rapid-onset follicular conjunctivitis or hemorrhages seen in AHC. **Analysis of Incorrect Options:** * **Enterovirus-70 & Coxsackie A-24:** These are the **most common causes** of epidemic outbreaks of AHC. They belong to the Picornaviridae family. They typically present with a short incubation period (12–48 hours) and "petechial" hemorrhages that rapidly coalesce. * **Adenovirus:** Specifically, **Serotypes 8, 11, and 19** are known to cause Epidemic Keratoconjunctivitis (EKC). While EKC is characterized by pseudomembranes and subepithelial infiltrates, it frequently presents with significant subconjunctival hemorrhage, making it a known cause of hemorrhagic conjunctivitis. **High-Yield Clinical Pearls for NEET-PG:** * **AHC Hallmark:** The hemorrhage usually starts in the upper bulbar conjunctiva and spreads downwards. * **Neurological Association:** Enterovirus-70 has a rare but classic association with **polio-like paralysis** (radiculomyelitis). * **Adenovirus (EKC):** Look for the "Rule of 8s"—caused by Adenovirus 8, symptoms last about 8 days, and subepithelial infiltrates appear 8 days after onset. * **Transmission:** Hand-to-eye contact and contaminated ophthalmic instruments (tonometers) are the primary routes.

Q: Hemorrhagic conjunctivitis occurs with which of the following?

Enterovirus. **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**. **Why Enterovirus is Correct:** The most common causative agents for AHC are **Enterovirus 70** and **Coxsackievirus A24**. These picornaviruses are transmitted via the feco-oral route or direct contact. The hallmark of this condition is the rapid appearance of petechial hemorrhages that coalesce to involve the entire bulbar conjunctiva. It typically occurs in large-scale epidemics, especially in overcrowded or coastal areas. **Why Other Options are Incorrect:** * **Herpes Simplex Virus (HSV):** Typically causes follicular conjunctivitis associated with dendritic keratitis. While it can cause redness, it does not typically present with the diffuse, frank hemorrhages seen in AHC. * **Herpes Zoster Virus (HZV):** Presents as blepharoconjunctivitis following the distribution of the ophthalmic nerve (V1). It is characterized by vesicular skin rashes and pseudodendrites rather than acute hemorrhagic episodes. **High-Yield Clinical Pearls for NEET-PG:** * **Incubation Period:** Very short (12–48 hours). * **Neurological Association:** Enterovirus 70 is rarely associated with a polio-like **radiculomyelitis** (lower motor neuron paralysis). * **Differential Diagnosis:** Adenovirus (Serotypes 8, 11, 19) causes **Epidemic Keratoconjunctivitis (EKC)**, which presents with pseudomembranes and subepithelial opacities, but hemorrhages are less pathognomonic than in Enterovirus. * **Management:** Purely supportive; topical steroids are generally contraindicated in the acute phase.

Q: Which bacterium causes acute hemorrhagic conjunctivitis?

Pneumococcus. **Explanation:** Acute Hemorrhagic Conjunctivitis (AHC) is a clinical variant of acute mucopurulent conjunctivitis characterized by the presence of multiple subconjunctival hemorrhages. **Why Pneumococcus is correct:** While AHC is most commonly caused by viruses (specifically **Enterovirus 70** and **Coxsackievirus A24**), among the bacterial causes, **Pneumococcus (*Streptococcus pneumoniae*)** is the classic culprit. It typically presents with a mucopurulent discharge and characteristic petechial or larger subconjunctival hemorrhages, often occurring in epidemic forms in temperate climates. **Analysis of Incorrect Options:** * **Staphylococcus aureus:** This is the most common cause of acute mucopurulent conjunctivitis globally. However, it typically presents with crusting of lids and a "stuck together" sensation in the morning, rather than significant subconjunctival hemorrhage. * **Streptococcus hemolyticus:** While it can cause severe conjunctivitis, it is more frequently associated with pseudomembrane formation rather than the hemorrhagic presentation typical of Pneumococcus. * **Pseudomonas:** This is a highly virulent organism associated with contact lens wear and corneal ulcers. It causes rapid liquefactive necrosis and a characteristic greenish discharge, but not primary hemorrhagic conjunctivitis. **High-Yield NEET-PG Pearls:** * **Viral Etiology:** If the question asks for the *most common* cause of AHC overall, the answer is **Enterovirus 70**. * **Clinical Sign:** Subconjunctival hemorrhages in Pneumococcal conjunctivitis are usually more prominent in the upper bulbar conjunctiva. * **Differential:** Always differentiate AHC from Epidemic Keratoconjunctivitis (EKC), which is caused by Adenovirus types 8 and 19 and presents with preauricular lymphadenopathy and corneal subepithelial infiltrates.

Q: All are features of Trachoma stage III, except?

Pannus. To understand this question, one must recall the **McCallan Classification** of Trachoma, which divides the disease into four clinical stages: 1. **Stage I (Incipient Trachoma):** Immature follicles on the upper tarsal conjunctiva. 2. **Stage II (Established Trachoma):** Mature follicles and papillary hypertrophy. 3. **Stage III (Cicatricial Trachoma):** Characterized by **scarring** (cicatrization). 4. **Stage IV (Healed Trachoma):** Disease is inactive; sequelae like entropion or trichiasis may be present. ### Why "Pannus" is the Correct Answer (The "Except") **Pannus** (vascularization and infiltration of the cornea) is a hallmark of **Stage II** (Active/Established Trachoma). While it may persist into later stages, it is the defining feature of the active inflammatory phase, not the cicatricial (scarring) phase. ### Explanation of Other Options (Features of Stage III) * **Herbert’s Pits:** These are pathognomonic small, circular depressions at the limbus. They represent the **scarred** remains of limbal follicles and are a classic sign of Stage III. * **Scar on Tarsal Conjunctiva:** This is the defining feature of Stage III. Linear or star-shaped scars (Arlt’s line) form as follicles necrose and heal. * **Necrosis in Scar:** During the transition to Stage III, the lymphoid follicles undergo necrosis, which is subsequently replaced by fibrous tissue (scarring). ### NEET-PG High-Yield Pearls * **Arlt’s Line:** A horizontal line of scarring found at the junction of the anterior 1/3rd and posterior 2/3rd of the tarsal conjunctiva (Stage III). * **Pathognomonic Sign:** Herbert’s pits are the most specific clinical sign of past Trachoma. * **WHO SAFE Strategy:** **S**urgery (for trichiasis), **A**ntibiotics (Azithromycin), **F**acial cleanliness, **E**nvironmental improvement. * **Causative Agent:** *Chlamydia trachomatis* serotypes A, B, Ba, and C.

Question 1

A 4-year-old child develops an infection with Chlamydia trachomatis. How does infection with this organism cause blindness?

Accepted Answer

Scarring of the cornea

Answer

Cataract formation

Answer

Hemorrhage into the anterior chamber

Answer

Hemorrhage into the posterior chamber

Question 2

What is a pterygium?

Accepted Answer

An inflammatory response

Answer

A connective tissue disorder

Answer

An infection

Answer

Associated with vitamin A deficiency

Question 3

Which organism commonly causes severe conjunctivitis?

Accepted Answer

Neisseria

Answer

Staphylococcus

Answer

Streptococcus

Answer

Haemophilus

Question 4

Which of the following is FALSE regarding phlyctenular conjunctivitis?

Accepted Answer

The most common cause is tuberculosis.

Answer

The lesions are typically found near the limbus.

Answer

Predominantly affects children.

Answer

Is a type IV hypersensitivity reaction.

Question 5

Which of the following are seen in trachoma?

Accepted Answer

All of the above

Answer

Papillary hypertrophy

Answer

Follicles

Answer

Panus formation

Question 6

Which of the following does not cause hemorrhagic conjunctivitis?

Accepted Answer

Papilloma virus

Answer

Adenovirus

Answer

Coxsackie – 24

Answer

Enterovirus – 70

Question 7

Hemorrhagic conjunctivitis occurs with which of the following?

Accepted Answer

Enterovirus

Answer

Herpes zoster

Answer

Herpes simplex

Answer

All of the above

Question 8

Which bacterium causes acute hemorrhagic conjunctivitis?

Accepted Answer

Pneumococcus

Answer

Staphylococcus aureus

Answer

Streptococcus hemolyticus

Answer

Pseudomonas

Question 9

Spring catarrh is which type of hypersensitivity reaction?

Accepted Answer

Type II

Answer

Type I

Answer

Type III

Answer

Type IV

Question 10

All are features of Trachoma stage III, except?

Accepted Answer

Pannus

Answer

Herbert's pits

Answer

Necrosis in scar

Answer

Scar on tarsal conjunctiva

Diseases of the Conjunctiva — MCQs

Diseases of the Conjunctiva — MCQs

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