Diseases of the Conjunctiva — MCQs

Diseases of the Conjunctiva Indian Medical PG Practice Questions and MCQs

Question 281: A 10-year-old boy presents with itching, redness, and tearing in his eyes, particularly during spring. What is the most likely diagnosis?

A. Vernal keratoconjunctivitis (Correct Answer)
B. Bacterial conjunctivitis
C. Acute iritis
D. Dry eye syndrome

Explanation: ***Vernal keratoconjunctivitis*** - This condition characteristically presents in **children and young adults**, often with a seasonal recurrence (spring) and symptoms of **itching, redness, and tearing**. - It is a severe form of **allergic conjunctivitis** with hallmark signs including **Trantas dots** (white limbal dots) and **cobblestone papillae** on the upper tarsal conjunctiva. *Bacterial conjunctivitis* - Typically presents with a **purulent discharge**, matting of the eyelids (especially in the morning), and is usually not seasonal. - It is often associated with a **bacterial infection**, rather than an allergic response. *Acute iritis* - Manifests with **eye pain, photophobia**, and circumcorneal redness, but typically without the marked **itching** or seasonal recurrence seen here. - It involves inflammation of the **iris and ciliary body**, distinguishable from conjunctival inflammation. *Dry eye syndrome* - Characterized by a gritty sensation, burning, and sometimes paradoxical tearing, but it is less common in childhood and usually lacks the prominent **itching** and strong seasonal component. - This condition is due to inadequate tear production or excessive tear evaporation, not an allergic response.

Question 282: A 25-year-old female presents with bilateral eye redness, a burning sensation, and dry eyes. The Schirmer test shows reduced tear production. What is the most likely diagnosis?

A. Dry eye syndrome (Correct Answer)
B. Allergic conjunctivitis
C. Blepharitis
D. Episcleritis

Explanation: ***Dry eye syndrome*** - The combination of **bilateral eye redness**, **burning sensation**, **dry eyes**, and **reduced tear production** on the **Schirmer test** are classic symptoms of dry eye syndrome. - This condition results from insufficient tear quantity or quality, leading to ocular surface irritation. *Allergic conjunctivitis* - While it causes **red eyes** and **burning**, it is typically associated with **itching**, which is not mentioned in the presentation. - Reduced tear production is not a primary feature; instead, there may be increased watery discharge. *Blepharitis* - This condition involves inflammation of the **eyelid margins** and is characterized by crusting, irritation, and sometimes dryness due to dysfunction of the meibomian glands. - While a burning sensation can occur, the primary finding of **reduced tear production** on the **Schirmer test** points away from isolated blepharitis. *Episcleritis* - Characterized by **localized redness** and discomfort, but typically does not involve a burning sensation or generalized dryness. - There is no reduction in tear production associated with episcleritis.

Question 283: Which of the following statements about conjunctival lesions is NOT true?

A. Arise from any part of conjunctiva
B. Can cause Astigmatism
C. Surgery is treatment of choice (Correct Answer)
D. UV exposure is risk factor

Explanation: ***Surgery is treatment of choice*** - While surgery can be used to treat conjunctival lesions, it is not always the **treatment of choice**, especially for smaller, asymptomatic lesions like **pinguecula** which may only require observation and lubrication. - Many conjunctival lesions, such as uncomplicated **pterygium** or **pinguecula**, are managed conservatively unless they cause significant symptoms, vision impairment, or cosmetic concerns. *Arise from any part of conjunctiva* - **Conjunctival lesions** can indeed arise from various parts of the conjunctiva, including the palpebral, bulbar, and forniceal conjunctiva. - For example, **pterygium** typically arises from the bulbar conjunctiva, while **pinguecula** also originates in the bulbar conjunctiva, specifically in the interpalpebral fissure. *Can cause Astigmatism* - Larger **conjunctival lesions**, particularly a **pterygium** that encroaches onto the cornea, can induce or alter astigmatism. - The growth of the lesion can change the **curvature of the cornea**, leading to optical distortion and astigmatism. *UV exposure is risk factor* - **Ultraviolet (UV) light exposure** is a well-established risk factor for the development of many conjunctival lesions, including **pterygium** and **pinguecula**. - Chronic UV exposure leads to **elastotic degeneration** of the conjunctival collagen and is thought to play a key role in the pathogenesis of these growths.

Question 284: What is the primary causative agent of swimming pool conjunctivitis?

A. Adenovirus type 3 (Correct Answer)
B. Chlamydia trachomatis
C. Adenovirus type 8
D. Gonococcus

Explanation: ***Adenovirus type 3*** - **Adenovirus type 3** is the most common cause of **pharyngoconjunctival fever**, often associated with outbreaks in swimming pools. - This condition is characterized by **acute follicular conjunctivitis**, fever, and pharyngitis. *Chlamydia trachomatis* - This bacterium causes **inclusion conjunctivitis**, which is typically associated with **genital infection** and can be transmitted to the eye. - It presents differently than swimming pool conjunctivitis, often with more chronic symptoms and potential for corneal involvement. *Adenovirus type 8* - **Adenovirus type 8** is a common cause of **epidemic keratoconjunctivitis (EKC)**, which is more severe and often involves corneal inflammation and scarring. - While an adenovirus, it is not the primary agent in typical "swimming pool conjunctivitis" outbreaks. *Gonococcus* - **Neisseria gonorrhoeae** causes severe hyperacute purulent conjunctivitis, especially in neonates (**ophthalmia neonatorum**), and can lead to rapid corneal perforation if untreated. - This is a distinct and much more serious condition not typically associated with swimming pools.

Question 285: Conjunctival staining is done by all except:

A. Rose Bengal
B. Lissamine
C. Fluorescein
D. India ink (Correct Answer)

Explanation: ***India ink*** - **India ink** is primarily used for staining capsules of microorganisms (e.g., *Cryptococcus neoformans*) in microbiology, not for ocular surface staining. - It is a **negative stain** that outlines the microbe rather than directly staining its parts. *Fluorescein* - **Fluorescein** is a common dye used to stain the **cornea** and **conjunctiva**, revealing abrasions, ulcers, and foreign bodies. - It highlights areas where epithelial cells are damaged, allowing it to penetrate into the bare stroma. *Rose Bengal* - **Rose Bengal** is used to stain **devitalized or degenerated epithelial cells** on the conjunctiva and cornea, particularly in dry eye syndrome. - It also stains **mucus filaments** and areas of tear film instability. *Lissamine* - **Lissamine green** is a vital dye similar to Rose Bengal, used to detect **devitalized conjunctival and corneal cells**. - It is often preferred over Rose Bengal because it causes less stinging and discomfort to the patient.

Question 286: What is the most common problem following surgical treatment of pterygium?

A. Recurrence (Correct Answer)
B. Corneal ulceration
C. Astigmatism
D. Scleral scarring

Explanation: ***Recurrence*** - **Pterygium recurrence** is the most frequent complication after surgical excision, with rates varying significantly based on the surgical technique used. - Factors like incomplete excision, younger age, and environmental exposures can increase the risk of the pterygium growing back. *Corneal ulceration* - **Corneal ulceration** is a serious but relatively rare complication of pterygium surgery, often associated with infection or improper wound healing. - While possible, it is not the most common problem observed post-operatively. *Astigmatism* - **Astigmatism** can be present before pterygium surgery due to the mass effect on the cornea or can be induced or altered by the surgery itself. - Although it can be a significant visual consequence, it is not the most common post-operative problem compared to recurrence. *Scleral scarring* - **Scleral scarring** can occur at the site of pterygium excision, especially if bare sclera techniques are used, or with extensive use of adjuncts like mitomycin C. - While it can be cosmetically unappealing or even sight-threatening in rare cases, it is less common than recurrence.

Question 287: What is the bacterial cause most commonly associated with hyperacute severe bacterial conjunctivitis?

A. Neisseria (Correct Answer)
B. Staphylococcus
C. Streptococcus
D. Haemophilus

Explanation: ***Neisseria*** - **Neisseria gonorrhoeae** and **Neisseria meningitidis** are well-known causes of hyperacute bacterial conjunctivitis because of their rapid onset and severe inflammatory response. - This form of conjunctivitis is characterized by abundant, thick purulent discharge and can rapidly lead to vision-threatening complications if not treated promptly. *Staphylococcus* - **Staphylococcus aureus** is a common cause of acute bacterial conjunctivitis, but it typically presents with a less severe, non-hyperacute course. - While it can cause significant inflammation, it rarely leads to the fulminant, rapid progression seen with Neisseria infections. *Streptococcus* - **Streptococcus pneumoniae** and **Streptococcus pyogenes** can cause bacterial conjunctivitis, often characterized by red, watery eyes and purulent discharge. - However, their presentation is generally acute rather than hyperacute, with a slower onset and progression compared to Neisseria. *Haemophilus* - **Haemophilus influenzae** is a common cause of bacterial conjunctivitis, particularly in children, often associated with otitis media. - The conjunctivitis caused by Haemophilus is typically acute and self-limiting, not characterized as hyperacute or severely rapidly progressive.

Question 288: Which of the following statements about pterygium is false?

A. Arise from any part of conjunctiva (Correct Answer)
B. Can cause astigmatism
C. Surgery is treatment of choice
D. UV exposure is risk factor

Explanation: ***Arise from any part of conjunctiva*** **(FALSE - Correct Answer)** - This statement is **FALSE** and thus the correct answer. - Pterygium characteristically arises from the **nasal (interpalpebral) bulbar conjunctiva** in 90-95% of cases. - It does NOT arise from "any part" - it has a specific predilection for the medial (nasal) limbus in the palpebral fissure zone. - Temporal pterygium is much less common (~10% of cases). *Can cause astigmatism* **(TRUE)** - This statement is TRUE. - As a pterygium grows across the cornea, it can induce **corneal astigmatism** by altering the curvature of the cornea. - This irregular corneal surface can blur vision, especially as the pterygium progresses towards the central visual axis. *Surgery is treatment of choice* **(TRUE)** - This statement is TRUE. - **Surgical excision** is the primary treatment for pterygium when it is symptomatic, threatens vision, or causes significant cosmetic concerns. - Indications for surgery include: growth towards the visual axis, inducing high astigmatism, significant discomfort, or cosmetic desire. - Adjunctive measures (mitomycin C, conjunctival autograft) help reduce recurrence. *UV exposure is risk factor* **(TRUE)** - This statement is TRUE. - **Ultraviolet (UV) radiation exposure** is a well-established and significant risk factor for the development and progression of pterygium. - This explains its higher prevalence in individuals living in sunny climates (between 37° N and 37° S latitude - "pterygium belt") and those with outdoor occupations.

Question 289: Unilateral frontal blisters with upper lid edema and conjunctivitis is seen in?

A. Herpes Simplex
B. Herpes Zoster Ophthalmicus (Correct Answer)
C. Neuroparalytic Keratitis
D. Acanthamoeba Keratitis

Explanation: ***Herpes Zoster Ophthalmicus*** - This condition is characterized by a **unilateral vesicular rash** (blisters) in the **trigeminal dermatome (V1)**, which includes the forehead and upper eyelid, along with significant **lid edema** and **conjunctivitis**. - **Hutchinson's sign** (lesions on the tip, side, or root of the nose) indicates a high risk of ocular involvement due to the nasociliary nerve innervation. *Acanthamoeba Keratitis* - This is an **amoebic infection** of the cornea typically associated with **contact lens wear** and often presents with severe pain and a **ring infiltrate** in the cornea. - It does not typically present with unilateral frontal blisters or significant lid edema. *Herpes Simplex* - Herpes simplex typically causes **recurrent corneal ulcers** (dendritic or geographic) and sometimes blepharitis, but not the widespread **unilateral frontal blisters** seen in the trigeminal distribution. - While it can cause conjunctivitis and lid edema, the pattern of skin lesions is the key differentiator. *Neuroparalytic Keratitis* - This condition results from **trigeminal nerve damage**, leading to corneal anesthesia and subsequent **trophic corneal ulceration**. - It presents primarily with **corneal findings** (epithelial defects, ulcers) due to impaired sensation and tear film stability, not initial vesicular skin lesions or prominent lid edema.

Question 290: Epithelial xerosis of conjunctiva is caused by?

A. Xerophthalmia (Correct Answer)
B. Infectious conjunctivitis caused by Chlamydia trachomatis
C. Autoimmune blistering conjunctivitis
D. Bacterial conjunctivitis due to Corynebacterium diphtheriae

Explanation: ***Xerophthalmia*** - **Xerophthalmia** is a medical condition characterized by **dryness of the eye**, often due to **vitamin A deficiency**. - **Epithelial xerosis of the conjunctiva** is one of the early and hallmark signs of xerophthalmia, representing the drying and thickening of the conjunctival epithelium due to goblet cell loss and squamous metaplasia. *Infectious conjunctivitis caused by Chlamydia trachomatis* - This typically causes **trachoma**, characterized by chronic inflammation, scarring, and eventual blindness. - While it can lead to dryness and scarring in later stages due to **symblepharon** or **entropion**, it does not primarily manifest as epithelial xerosis. *Autoimmune blistering conjunctivitis* - This condition involves **immune-mediated inflammation** leading to subepithelial blistering, scarring, and shrinkage of the conjunctiva. - It results in significant **ocular surface damage** and vision loss but is distinct from the primary epithelial changes seen in xerosis due to vitamin A deficiency. *Bacterial conjunctivitis due to Corynebacterium diphtheriae* - **Diphtheritic conjunctivitis** is a severe form of bacterial conjunctivitis that causes a distinctive **"pseudomembrane"** on the conjunctiva. - It leads to acute inflammation and potentially systemic illness, not primarily epithelial xerosis.

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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