NEET-PG 2013 Practice Questions

Q: Scissor reflex is seen in ?

Keratoconus. ***Keratoconus*** - The **scissor reflex**, or **scissoring reflex**, is a characteristic finding during **retinoscopy** in patients with **keratoconus**. - It is caused by the irregular and variable refractive power across the cornea, leading to a distorted red reflex that appears to split into two bands moving in opposite directions. *Open angle glaucoma* - **Open-angle glaucoma** is characterized by progressive damage to the **optic nerve** and visual field loss, typically with a normal open anterior chamber angle. - It does not involve abnormalities in corneal shape or light refraction that would produce a scissor reflex during retinoscopy. *Phlyctenular conjunctivitis* - **Phlyctenular conjunctivitis** is an inflammatory condition characterized by small nodular lesions (phlyctenules) on the conjunctiva or cornea, often associated with a hypersensitivity reaction to microbial antigens. - This condition primarily affects the surface of the eye and does not cause the corneal ectasia or irregular astigmatism seen in keratoconus. *Interstitial keratitis* - **Interstitial keratitis** is an inflammation of the corneal stroma without significant involvement of the epithelium or endothelium, often associated with systemic infections like syphilis or Lyme disease. - While it can cause corneal opacification and vision loss, it typically does not lead to the conical shape or irregular astigmatism characteristic of keratoconus, which produces the scissor reflex.

Q: Non-sterile hypopyon is seen in ?

Fungal infection. ***Fungal infection*** - **Fungal keratitis** produces a **non-sterile hypopyon**, meaning the hypopyon contains actual fungal elements and organisms, not just inflammatory cells alone. - This is characteristically seen with **filamentous fungi** (Aspergillus, Fusarium) and yeast (Candida), which can directly invade the anterior chamber. - The hypopyon is typically **indolent, greyish-white, and does not shift with position** unlike bacterial hypopyon, and shows poor response to antibacterial therapy. - **Fungal culture and KOH mount** are diagnostic. *Pneumococcal infection* - **Bacterial keratitis** caused by *Streptococcus pneumoniae* produces a **sterile hypopyon** consisting purely of inflammatory cells (polymorphonuclear leukocytes) without organisms in the anterior chamber. - Presents with **acute onset, severe pain, and rapid progression** with a dense stromal infiltrate. - The hypopyon is **white, mobile, and shifts with head position**. *Pseudomonas aeruginosa infection* - **Pseudomonas keratitis** causes an aggressive infection with a **sterile hypopyon** due to intense inflammatory response. - Characterized by **rapidly progressive stromal necrosis** with a ground-glass appearance and greenish discharge. - Often associated with **contact lens wear** and can lead to corneal perforation within 24-48 hours. *Gonococcal conjunctivitis* - **Neisseria gonorrhoeae conjunctivitis** causes severe **hyperacute purulent conjunctivitis** with copious discharge. - Typically does **not cause hypopyon** unless there is secondary corneal ulceration leading to keratitis or endophthalmitis. - Primary manifestation is conjunctival inflammation, chemosis, and lid edema.

Q: Ameboid ulcers are primarily associated with which type of corneal ulcer?

Acanthamoeba corneal ulcer. ***Acanthamoeba corneal ulcer*** - **Acanthamoeba** infections are classically associated with **ameboid ulcers** due to the movement and destructive nature of this protozoan. - This type of ulcer often presents with severe pain, disproportionate to clinical findings, and can have a **ring infiltrates** appearance. *Fungal corneal ulcer* - Fungal ulcers typically present with a **feathery border** and satellite lesions, not ameboid shapes. - They are often associated with a history of **ocular trauma** involving plant material. *Herpetic corneal ulcer* - Herpetic ulcers are characterized by a **dendritic pattern** (tree-branch-like), which is distinct from an ameboid shape. - They are caused by the **herpes simplex virus** and can lead to recurrent episodes. *Bacterial corneal ulcer* - Bacterial ulcers typically present as a **round or oval infiltrate** with stromal edema and an overlying epithelial defect. - They can progress rapidly and are not described as having an **ameboid configuration**.

Q: Keratitis in contact lens wearers is caused by all except?

Pneumococcus. ***Pneumococcus*** - While *Streptococcus pneumoniae* (Pneumococcus) can cause bacterial keratitis, it is **classically associated with corneal ulcers following trauma** rather than contact lens wear. - In contact lens-related keratitis, Pneumococcus is **significantly less common** compared to *Pseudomonas*, which dominates as the primary bacterial pathogen in this setting. - Pneumococcal keratitis typically presents with a **well-demarcated, dense purulent ulcer with hypopyon**, often following corneal injury. *Pseudomonas* - **_Pseudomonas aeruginosa_** is **the most common cause of bacterial keratitis in contact lens wearers**, accounting for the majority of severe cases. - It thrives in moist environments such as contaminated contact lens cases and solutions, producing **exotoxins and proteases that cause rapid corneal destruction and tissue melt**. - Presents with a **rapidly progressive, dense stromal infiltrate** with a characteristic **ground-glass appearance** and potential for perforation. *Aspergillus* - **_Aspergillus_ species** are an important cause of **fungal keratitis**, particularly associated with contact lens wear, poor lens hygiene, and contaminated lens solutions. - Fungal keratitis presents with **feathery-edged infiltrates, satellite lesions**, and ring-shaped infiltrates, often requiring antifungal therapy. - More common in tropical climates and agricultural settings. *Chlamydia* - **_Chlamydia trachomatis_** is primarily a cause of **trachoma** (chronic follicular conjunctivitis leading to scarring) and **adult inclusion conjunctivitis**. - While it can cause **superficial punctate keratitis and pannus formation** in trachoma, it is **NOT a typical cause of acute suppurative keratitis in contact lens wearers**. - The acute bacterial and fungal keratitis seen in contact lens wearers is a different clinical entity from chlamydial conjunctivitis/keratopathy.

Q: What is the most common infection in contact lens users?

Pseudomonas. ***Pseudomonas*** - **Pseudomonas aeruginosa** is the leading cause of **bacterial keratitis** in contact lens wearers, accounting for 60-70% of culture-positive cases - This bacterium can **adhere to lenses**, form **biofilms**, and thrive in moist lens storage cases - Can cause rapid and severe corneal damage with **corneal ulceration**, potentially leading to **vision loss** *Staphylococcus* - **Staphylococcus aureus** and **Staphylococcus epidermidis** are common commensals of the skin and can cause eye infections, including keratitis and blepharitis - However, in the context of contact lens-related keratitis, **Pseudomonas aeruginosa** remains the primary pathogen for severe corneal infections *Streptococcus* - While various **Streptococcus species** (especially S. pneumoniae) can cause bacterial keratitis, they are less commonly associated with contact lens-related keratitis compared to Pseudomonas - **Streptococcal keratitis** typically occurs in non-contact lens wearers or after trauma *Neisseria* - **Neisseria gonorrhoeae** can cause hyperacute bacterial conjunctivitis with severe purulent discharge, but is not the most common cause of contact lens-related keratitis - **Neisseria meningitidis** can rarely cause conjunctivitis, but these infections usually indicate specific exposure or systemic disease

Q: The immune ring is a feature associated with which condition?

Fungal corneal ulcer. ***Fungal corneal ulcer*** - The **immune ring** (also known as a **Wessely ring**) is a characteristic sign seen in **fungal corneal ulcers**, particularly those caused by filamentous fungi. - It represents a **circumferential infiltrate** of immune cells and antigen-antibody complexes. *Interstitial keratitis* - Characterized by **stromal inflammation** without primary involvement of the epithelium or endothelium, often leading to ghost vessels after treatment. - It is typically associated with conditions like **syphilis** or other systemic infections, not an immune ring. *Bacterial corneal ulcer* - Often presents with a **rapidly progressing** corneal infiltrate, significant pain, and sometimes **hypopyon**. - While an immune response occurs, it does not typically form a distinct, well-defined **immune ring** like in fungal infections. *Herpes simplex keratitis* - Classically manifests as a **dendritic ulcer** or geographic ulcer, which can progress to stromal keratitis. - The immune ring is **not a feature** of herpes simplex keratitis; distinctive patterns like dendrites or disciform keratitis are seen.

Q: Reis-Buckler dystrophy affects which layer of the cornea?

Bowman's membrane. ***Bowman's membrane*** - **Reis-Buckler dystrophy** is a type of corneal dystrophy specifically characterized by the progressive destruction and irregular regeneration of **Bowman's membrane** and the superficial stroma. - This leads to the formation of an abnormal fibrous layer that causes recurrent corneal erosions and significant visual impairment due to corneal opacification. *Epithelium* - While patients often experience recurrent **corneal erosions** involving the epithelium, the primary pathology in Reis-Buckler dystrophy affects the underlying Bowman's membrane. - The epithelial damage is secondary to the irregular surface created by the diseased Bowman's layer. *Stroma* - The **stroma** can be secondarily affected with superficial scarring and opacification in Reis-Buckler dystrophy, but the initial and primary site of pathology is Bowman's membrane. - Other dystrophies, such as macular or granular dystrophies, primarily involve the corneal stroma. *Endothelium* - The **endothelium** is not directly affected in Reis-Buckler dystrophy. - Endothelial dystrophies, such as Fuchs' endothelial dystrophy, involve the innermost layer of the cornea and lead to corneal edema.

Q: Which of the following statements about Fuchs' corneal dystrophy is incorrect?

Unilateral condition. ***Unilateral condition - INCORRECT STATEMENT*** - **Fuchs' corneal dystrophy** is typically a **bilateral condition**, although it can be asymmetric in its presentation. - The disease often affects both eyes, progressing from early morning blurriness to constant visual impairment. - This is the INCORRECT statement - Fuchs' is NOT unilateral. *Posterior dystrophy - Correct statement* - **Fuchs' corneal dystrophy** is classified as a posterior corneal dystrophy, meaning it primarily affects the **corneal endothelium** and Descemet's membrane. - This posterior involvement leads to the characteristic guttata and corneal edema. *Endothelial dystrophy - Correct statement* - It is fundamentally an **endothelial dystrophy**, resulting from primary dysfunction and loss of corneal endothelial cells. - The compromised endothelial pump function leads to **stromal edema** and reduced visual acuity. *Occurs in old age - Correct statement* - Fuchs' corneal dystrophy typically presents in **middle to old age**, with symptoms often becoming noticeable in individuals over 50. - While congenital forms of corneal dystrophy exist, Fuchs' is not usually one of them.

Q: Corneal sensations are decreased in all of the following conditions except:

Recurrent corneal erosion syndrome. ***Recurrent corneal erosion syndrome*** - This condition involves **defective adhesion** of the corneal epithelium to the underlying Bowman's layer and basement membrane, leading to sudden, severe pain upon waking. - While it causes **pain** and **epithelial defects**, it does not primarily involve nerve damage or decreased corneal sensation; rather, episodes are often very painful due to exposed nerve endings. *Herpetic keratitis* - Caused by the **herpes simplex virus (HSV)**, which can infect the trigeminal nerve and lead to **trophic changes** in the cornea. - This viral infection often results in **significant reduction** or loss of corneal sensation, making the eye more vulnerable to trauma and delayed healing. *Neuroparalytic keratitis* - This condition is also known as **neurotrophic keratitis** and results from damage to the **trigeminal nerve**, which supplies sensation to the cornea. - Loss of corneal sensation leads to impaired reflex tearing and blinking, making the cornea susceptible to epithelial breakdown and ulceration due to lack of protective mechanisms. *Leprosy* - In ocular leprosy, the **Mycobacterium leprae** directly invades the ciliary nerves, significantly impairing corneal sensation. - This reduced sensation in leprosy patients increases the risk of **corneal ulcers** and opacification due to undetected foreign bodies and trauma.

Q: Interstitial keratitis is associated with all of the following except:

Acanthamoeba. ***Acanthamoeba*** - **Acanthamoeba keratitis** is a **suppurative keratitis** characterized by a painful, ring-shaped infiltrate with epithelial ulceration, typically associated with contact lens use and contaminated water exposure. - It causes **ulcerative stromal inflammation**, not the **non-ulcerative deep stromal inflammation** that characterizes classic interstitial keratitis. - **This is NOT a cause of interstitial keratitis.** *Syphilis* - **Congenital syphilis** is the **CLASSIC cause** of bilateral **interstitial keratitis**, often presenting in late childhood with "salmon patch" appearance, photophobia, lacrimation, and eventual ghost vessels. - The inflammation is **non-ulcerative and chronic**, affecting the **deep corneal stroma** with preservation of epithelium. - This is the most important association with interstitial keratitis to remember. *Chlamydia Trachomatis* - **Chlamydia trachomatis** causes **trachoma**, a chronic keratoconjunctivitis leading to **superficial keratitis with pannus formation** (superficial vascularization from the limbus). - The corneal involvement in trachoma is **superficial**, not the deep stromal inflammation seen in classic interstitial keratitis. - While listed in some references, **Chlamydia is NOT a standard cause of interstitial keratitis** in major ophthalmology textbooks. - **Note:** This option is potentially debatable, but Acanthamoeba is the more definitively incorrect answer. *Herpes Zoster Virus (HZV)* - **Herpes zoster ophthalmicus** can lead to **interstitial keratitis** and **disciform keratitis** (immune-mediated stromal inflammation with disc-shaped corneal edema). - Similarly, **HSV (Herpes Simplex Virus)** causes stromal keratitis, a form of interstitial keratitis. - The corneal involvement includes **deep stromal inflammation, scarring**, and potential neurotrophic changes leading to vision impairment.

Question 1

Scissor reflex is seen in ?

Accepted Answer

Keratoconus

Answer

Open angle glaucoma

Answer

Phlyctenular conjunctivitis

Answer

Interstitial keratitis

Question 2

Non-sterile hypopyon is seen in ?

Accepted Answer

Fungal infection

Answer

Pneumococcal infection

Answer

Pseudomonas aeruginosa infection

Answer

Gonococcal conjunctivitis

Question 3

Ameboid ulcers are primarily associated with which type of corneal ulcer?

Accepted Answer

Acanthamoeba corneal ulcer

Answer

Fungal corneal ulcer

Answer

Bacterial corneal ulcer

Answer

Herpetic corneal ulcer

Question 4

Keratitis in contact lens wearers is caused by all except?

Accepted Answer

Pneumococcus

Answer

Chlamydia

Answer

Aspergillus

Answer

Pseudomonas

Question 5

What is the most common infection in contact lens users?

Accepted Answer

Pseudomonas

Answer

Streptococcus

Answer

Staphylococcus

Answer

Neisseria

Question 6

The immune ring is a feature associated with which condition?

Accepted Answer

Fungal corneal ulcer

Answer

Interstitial keratitis

Answer

Bacterial corneal ulcer

Answer

Herpes simplex keratitis

Question 7

Reis-Buckler dystrophy affects which layer of the cornea?

Accepted Answer

Bowman's membrane

Answer

Stroma

Answer

Endothelium

Answer

Epithelium

Question 8

Which of the following statements about Fuchs' corneal dystrophy is incorrect?

Accepted Answer

Unilateral condition

Answer

Endothelial dystrophy

Answer

Occurs in old age

Answer

Posterior dystrophy

Question 9

Corneal sensations are decreased in all of the following conditions except:

Accepted Answer

Recurrent corneal erosion syndrome

Answer

Neuroparalytic keratitis

Answer

Leprosy

Answer

Herpetic keratitis

Question 10

Interstitial keratitis is associated with all of the following except:

Accepted Answer

Acanthamoeba

Answer

Syphilis

Answer

Chlamydia Trachomatis

Answer

Herpes Zoster Virus (HZV)

NEET-PG 2013

Ophthalmology