Diseases of the Cornea Practice Questions

Q: All are causes of a non-healing corneal ulcer except?

Associated iridocyclitis. **Explanation:** A non-healing (indolent) corneal ulcer is one that fails to show signs of healing despite appropriate antimicrobial therapy. The management of such cases requires identifying and treating the underlying systemic or local factors that impede epithelialization. **Why "Associated Iridocyclitis" is the correct answer:** Iridocyclitis (anterior uveitis) is a **common clinical feature** of almost all significant corneal ulcers due to the diffusion of toxins into the anterior chamber. It is a *consequence* of the ulcer, not a cause of delayed healing. In fact, treating the associated iridocyclitis with cycloplegics (like Atropine) is a standard part of the management to reduce pain and prevent synechiae. **Analysis of Incorrect Options (Causes of Non-healing Ulcers):** * **Raised Intraocular Pressure (A):** Increased IOP causes mechanical stress on the corneal endothelium and stroma, leading to corneal edema. This interferes with the migration and adhesion of the epithelial basement membrane, preventing the ulcer from healing. * **Chronic Dacryocystitis (C):** This is a classic "high-yield" cause. The lacrimal sac acts as a reservoir for bacteria (commonly *S. pneumoniae*), leading to a constant "rain of infection" onto the cornea, causing recurrence or non-healing. * **Diabetes Mellitus (D):** Systemic conditions like DM impair healing through peripheral neuropathy (decreased corneal sensation/neurotrophic effect) and impaired microcirculation and immune response. **Clinical Pearls for NEET-PG:** * **Most common cause of a non-healing ulcer:** Local factors like Chronic Dacryocystitis or Lagophthalmos. * **Rule of thumb:** Always check the patency of the lacrimal passages (Syringing) in any patient with a corneal ulcer. * **Other causes:** Vitamin A deficiency, Neurotrophic keratitis (CN V palsy), and Corticosteroid abuse.

Q: A soft contact lens wearer developed pain and itching of the eye and showed a reticular pattern on the corneal epithelium. What is the likely cause of these symptoms?

Acanthamoeba infection. ### Explanation **Correct Answer: B. Acanthamoeba infection** The clinical presentation of a **soft contact lens wearer** presenting with severe pain and a **reticular (radial) pattern** on the cornea is a classic description of **Acanthamoeba keratitis**. The "reticular pattern" refers to **radial keratoneuritis**, which is the infiltration of the corneal nerves by the *Acanthamoeba* trophozoites. This involvement of the nerves explains why the pain is often **disproportionate** to the clinical signs (severe pain despite minimal initial findings). Contact lens wear, especially with poor hygiene or use of tap water, is the most significant risk factor. **Why other options are incorrect:** * **Corneal dystrophy (A):** These are typically bilateral, symmetrical, and slowly progressive genetic conditions. They do not present with acute pain or itching associated with contact lens use. * **Pseudomonas infection (C):** While common in contact lens wearers, *Pseudomonas* causes a rapidly progressing suppurative ulcer with a characteristic **greenish-yellow discharge** and a large hypopyon, rather than a radial nerve pattern. * **Viral keratitis (D):** Herpes Simplex Keratitis typically presents with a **dendritic ulcer** (linear branching with terminal bulbs) and decreased corneal sensations, rather than the intense pain of radial keratoneuritis. **High-Yield Clinical Pearls for NEET-PG:** * **Pathognomonic Sign:** Radial keratoneuritis (radial perineural infiltrates). * **Late Sign:** Ring-shaped stromal infiltrate. * **Diagnosis:** Culture on **Non-nutrient agar with E. coli overlay**. * **Stains:** Calcofluor white (fluorescent) or Periodic acid-Schiff (PAS). * **Treatment:** Topical biguanides (PHMB 0.02%) or Diamidines (Propamidine/Brolene).

Q: Fascicular ulcer is seen in which of the following conditions?

Phlyctenular keratitis. ### Explanation **Phlyctenular keratitis** is the correct answer because a **fascicular ulcer** is its most characteristic clinical manifestation. #### 1. Why Phlyctenular Keratitis is Correct Phlyctenular keratoconjunctivitis is a delayed hypersensitivity reaction (Type IV) to endogenous bacterial proteins, most commonly **Tuberculosis** (in developing countries) or **Staphylococcus** (in developed countries). * **Mechanism of Fascicular Ulcer:** A phlycten (a small greyish nodule) starts at the limbus and migrates towards the center of the cornea. As it moves, it carries a "leash" of superficial blood vessels behind it. The leading edge remains an active ulcer while the trailing edge heals, resulting in a **serpiginous, wandering ulcer** with a characteristic vascular leash. It typically does not perforate but leaves a permanent superficial opacity (nebula). #### 2. Why Other Options are Incorrect * **Rosacea Keratitis:** Characteristically presents with peripheral corneal vascularization, marginal infiltrates, and spade-shaped scarring. It is associated with acne rosacea of the face. * **Riboflavin (Vitamin B2) Deficiency:** Classically associated with **circumcorneal vascularization** (neovascularization) and angular stomatitis, but it does not produce a migrating fascicular ulcer. #### 3. High-Yield Clinical Pearls for NEET-PG * **Etiology:** Always look for "History of TB" or "Positive Mantoux test" in the clinical vignette. * **Symptoms:** Intense photophobia is a hallmark when the cornea is involved. * **Treatment:** Topical steroids are the mainstay to control the hypersensitivity reaction, along with treating the underlying cause (e.g., ATT for TB or lid hygiene for Staph). * **Differential Diagnosis:** Do not confuse the vascular leash of a fascicular ulcer with a **Pannus** (seen in Trachoma), which is inflammatory vascularization usually limited to the upper quadrant.

Q: A 55-year-old cardiac patient on long-term treatment presents for a follow-up visit. The physician observes the following finding on ophthalmological examination. Which drug prescribed by the physician would most probably be responsible for this?

Amiodarone. ***Amiodarone*** - **Amiodarone** commonly causes **corneal microdeposits** (vortex keratopathy/cornea verticillata) in up to 90% of patients on long-term therapy, appearing as whorl-like deposits in the corneal epithelium. - These deposits are **reversible** upon discontinuation and rarely affect vision, making them a characteristic but benign finding in amiodarone users. *Digoxin* - **Digoxin toxicity** primarily causes **visual disturbances** like yellow-green halos and blurred vision, not corneal deposits. - Ocular effects are related to **retinal toxicity** and altered color perception rather than structural corneal changes. *Verapamil* - **Verapamil** is a calcium channel blocker that does not typically cause **corneal deposits** or significant ophthalmological findings. - Side effects are primarily cardiovascular (bradycardia, hypotension) and do not include characteristic ocular manifestations. *Propranolol* - **Propranolol** may cause **dry eyes** and reduced tear production but does not cause corneal microdeposits. - Beta-blockers can worsen **glaucoma** in susceptible patients but do not produce the whorl-like corneal pattern seen with amiodarone.

Q: What are the characteristic features of a fungal corneal ulcer?

Dry ulcer. **Explanation:** Fungal corneal ulcers (keratomycosis) typically present with distinct clinical features that differentiate them from bacterial ulcers. The correct answer is **Dry ulcer** because fungal lesions are characterized by a firm, elevated, and leathery texture. Unlike the "wet" or melting appearance of bacterial ulcers, fungal hyphae infiltrate the stroma without producing the same level of liquefactive necrosis, leading to a **dry, grayish-white appearance**. **Analysis of Options:** * **A. Symptoms disproportionate to signs:** This is a classic feature of **Acanthamoeba keratitis**, where the patient experiences excruciating pain despite minimal clinical findings. In fungal ulcers, the opposite is often true: signs are often more prominent than symptoms (the patient may feel relatively comfortable despite a large ulcer). * **C. Diffuse corneal edema:** While some edema may occur, it is not a "characteristic" diagnostic feature. Fungal ulcers are more specifically known for **Feathered margins**, **Satellite lesions**, and an **Immune ring (Wessely ring)**. * **D. All of the above:** Incorrect, as options A and C are not primary characteristics of fungal keratitis. **NEET-PG High-Yield Pearls:** * **Etiology:** Most common cause in India is *Aspergillus* (filamentous); *Candida* is more common in pre-existing ocular surface disease. * **Risk Factor:** Trauma with **vegetative matter** (e.g., a branch or leaf). * **Clinical Signs:** Look for "Fixed Hypopyon" (thick, non-mobile) and "Endothelial plaques." * **Diagnosis:** **KOH mount** (10-20%) is the fastest bedside test; **Sabouraud’s Dextrose Agar (SDA)** is the gold standard culture medium. * **Treatment:** Topical **Natamycin (5%)** is the drug of choice for filamentous fungi. Avoid topical steroids as they worsen the infection.

Q: What is the characteristic color of fluorescein staining in a corneal ulcer?

Green. **Explanation:** **Mechanism of Staining:** Sodium Fluorescein is a vital dye used to assess corneal integrity. It is **water-soluble** and cannot penetrate the intact, lipid-rich corneal epithelium. In a corneal ulcer, the epithelium is breached, exposing the underlying **corneal stroma**. The dye dissolves into the stromal fluid, and when viewed under a **cobalt blue light**, it fluoresces a brilliant **apple-green** color. **Analysis of Options:** * **D. Green (Correct):** This is the characteristic color of fluorescence. The dye absorbs blue light (wavelength ~490 nm) and emits a longer wavelength in the green spectrum (~525 nm). * **A. Yellow:** While the fluorescein strip or concentrated drops appear orange-yellow to the naked eye, the diagnostic "staining" refers to the fluorescence seen under blue light, which is green. * **B. & C. Blue/Royal Blue:** These represent the color of the **filter** (Cobalt blue) used on the slit lamp to excite the dye, not the color of the stain itself. **Clinical Pearls for NEET-PG:** * **Seidel’s Test:** Used to detect aqueous leakage (e.g., globe perforation). A positive test shows a "streaming" of clear aqueous fluid through the green fluorescein. * **Dendritic Ulcers:** Fluorescein stains the **bed** of the ulcer (where cells are missing), while Rose Bengal or Lissamine Green stains the **devitalized cells** at the margins. * **Contact Lenses:** Fluorescein should be avoided with soft contact lenses as it permanently stains them. * **Jones Test:** Uses fluorescein to check the patency of the nasolacrimal duct.

Q: Which of the following are features of a fungal corneal ulcer?

Hyphenated margins. **Explanation:** Fungal corneal ulcers (keratomycosis), most commonly caused by *Aspergillus*, *Fusarium*, or *Candida*, present with distinct clinical features due to the slow-growing nature of fungi and the host's inflammatory response. **Why "Hyphenated margins" is correct:** Fungal hyphae tend to infiltrate the corneal stroma by spreading horizontally and vertically. This creates irregular, feathery, or **hyphenated margins** around the main ulcer. Other characteristic features include a **dry, leathery appearance**, **satellite lesions** (small infiltrates away from the main ulcer), and a **fixed hypopyon** (which is often sterile but thick and non-mobile). **Analysis of Incorrect Options:** * **A. Symptoms more than signs:** This is a hallmark of **Acanthamoeba keratitis**, where the pain is excruciating and out of proportion to the clinical findings. In fungal ulcers, signs are often more prominent than symptoms (the patient may feel relatively comfortable despite a large ulcer). * **B. Dry ulcer:** While fungal ulcers are indeed "dry" and "leathery," this option is less specific than "hyphenated margins" in the context of classic board-style questions. However, in some contexts, this is a feature; but hyphenated margins are the pathognomonic clinical sign. * **C. Diffuse corneal edema:** This is more characteristic of **Bacterial ulcers** or acute glaucoma. Fungal ulcers typically have localized edema around the infiltrate rather than diffuse edema. **High-Yield Clinical Pearls for NEET-PG:** * **History:** Often follows trauma with **vegetative matter** (e.g., a branch or leaf). * **Immune Ring:** A Wessely immune ring may be seen (host response to fungal antigens). * **Diagnosis:** Gold standard is **Sabouraud’s Dextrose Agar (SDA)**; KOH mount shows hyphae. * **Treatment:** Topical **Natamycin** (5%) is the drug of choice for filamentous fungi; Amphotericin B for *Candida*. Avoid steroids.

Q: Which of the following stains is used in granular dystrophy of the cornea?

Masson's trichrome. **Explanation:** Corneal dystrophies are a high-yield topic for NEET-PG, often tested through the association of specific deposits with their respective histological stains. **1. Why Masson’s Trichrome is Correct:** **Granular Dystrophy** is characterized by the deposition of **hyaline material** in the superficial stroma. On histopathology, these deposits appear as bright red granules when stained with **Masson’s Trichrome**. This is the gold-standard stain for identifying hyaline in corneal tissue. **2. Analysis of Incorrect Options:** * **A. Congo-red:** This is the specific stain for **Lattice Dystrophy**, which involves the deposition of **amyloid**. Under polarized light, Congo-red stained amyloid shows a characteristic "apple-green birefringence." * **C. Colloidal Iron:** This (along with Alcian Blue) is used to stain **Macular Dystrophy**, which involves the deposition of **Acid Mucopolysaccharides (Glycosaminoglycans)**. * **D. PAS (Periodic Acid-Schiff):** While PAS stains basement membranes and certain carbohydrates, it is not the primary diagnostic stain for Granular Dystrophy. It is more commonly associated with fungal filaments or Descemet’s membrane pathology. **3. High-Yield Clinical Pearls (Mnemonic: "Marilyn Monroe Got Hers"):** To remember the associations for NEET-PG, use this classic mnemonic: * **M**acular – **M**ucopolysaccharide – **A**lcian Blue/Colloidal Iron (**M.A.**) * **G**ranular – **H**yaline – **M**asson’s Trichrome (**G.H.M.**) * **L**attice – **A**myloid – **C**ongo Red (**L.A.C.**) **Additional Fact:** Granular Dystrophy is an **Autosomal Dominant** condition (TGFBI gene mutation) and typically presents with "crumb-like" opacities with clear spaces in between.

Q: Hutchinson's rule is related to which of the following conditions?

Herpes zoster ophthalmicus. **Explanation:** **Hutchinson’s Rule** is a clinical sign used to predict ocular involvement in **Herpes Zoster Ophthalmicus (HZO)**. It states that if the tip, side, or root of the nose is involved with herpetic vesicles, there is a high probability (approx. 75%) of subsequent ocular inflammation. **1. Why Option C is Correct:** The rule is based on the anatomy of the **Nasociliary nerve**, which is a branch of the Ophthalmic division (V1) of the Trigeminal nerve. The nasociliary nerve provides sensory innervation to both the **eyeball** (via long and short ciliary nerves) and the **skin of the tip of the nose** (via the external nasal nerve). Therefore, cutaneous lesions on the nose indicate that the nasociliary nerve is involved, making intraocular inflammation (keratitis, uveitis) highly likely. **2. Why Other Options are Incorrect:** * **Option A (Herpes Simplex Keratitis):** While caused by a related virus, HSV typically presents with dendritic ulcers and does not follow the dermatomal distribution or the specific nasociliary pattern associated with Hutchinson’s rule. * **Option B (Mycotic Keratitis):** This is a fungal infection usually following trauma with vegetative matter. It presents with feathery margins and satellite lesions, unrelated to viral dermatomal patterns. **High-Yield Clinical Pearls for NEET-PG:** * **Pseudodendrite:** HZO causes "pseudodendrites" (stuck-on appearance, no terminal bulbs), unlike the true dendrites of HSV. * **Most common ocular complication of HZO:** Anterior Uveitis. * **Treatment:** Oral Acyclovir (800 mg 5x daily for 7–10 days) started within 72 hours of rash onset. * **Note:** Hutchinson’s rule is not absolute; ocular involvement can occur even if the nose is spared (approx. 30% risk).

Q: True about Fuchs endothelial dystrophy are all except?

Symmetrical and bilateral condition. **Explanation:** Fuchs Endothelial Corneal Dystrophy (FECD) is a progressive, hereditary disorder characterized by the primary loss of corneal endothelial cells. **Why Option B is the Correct Answer (The "Except"):** While FECD is a **bilateral** condition, it is characteristically **asymmetrical**. Although both eyes are affected, one eye typically shows more advanced progression or severe edema than the other. In NEET-PG, distinguishing between "bilateral and symmetrical" (typical of most dystrophies) and "bilateral but asymmetrical" (typical of Fuchs) is a high-yield point. **Analysis of Other Options:** * **Option A:** FECD shows a strong female predilection (3:1 ratio) and typically manifests in the 5th to 6th decades of life (elderly). * **Option C:** **Cornea guttata** (beaten metal appearance) is the hallmark clinical sign. These are drop-like excrescences of Descemet’s membrane resulting from endothelial dysfunction. * **Option D:** Patients often complain of **early morning blurring and halos**. This occurs because the eyelids are closed during sleep, preventing tear evaporation and increasing corneal hypoxia, which worsens stromal edema. Vision improves throughout the day as evaporation reduces the swelling. **High-Yield Clinical Pearls for NEET-PG:** * **Inheritance:** Autosomal Dominant (most common). * **Pathophysiology:** Loss of Na+/K+ ATPase pumps in the endothelium leads to stromal and epithelial edema. * **Stages:** Starts with Guttata $\rightarrow$ Stromal Edema $\rightarrow$ Bullous Keratopathy $\rightarrow$ Corneal Scarring. * **Management:** Hypertonic saline (5% NaCl) drops/ointment; definitive treatment is Keratoplasty (DMEK/DSAEK are preferred over PK).

Question 1

All are causes of a non-healing corneal ulcer except?

Accepted Answer

Associated iridocyclitis

Answer

Raised intraocular pressure

Answer

Chronic dacryocystitis

Answer

Diabetes mellitus

Question 2

A soft contact lens wearer developed pain and itching of the eye and showed a reticular pattern on the corneal epithelium. What is the likely cause of these symptoms?

Accepted Answer

Acanthamoeba infection

Answer

Corneal dystrophy

Answer

Pseudomonas infection

Answer

Viral keratitis

Question 3

Fascicular ulcer is seen in which of the following conditions?

Accepted Answer

Phlyctenular keratitis

Answer

Rosacea keratitis

Answer

Riboflavin deficiency

Answer

All of the above

Question 4

A 55-year-old cardiac patient on long-term treatment presents for a follow-up visit. The physician observes the following finding on ophthalmological examination. Which drug prescribed by the physician would most probably be responsible for this?

Accepted Answer

Amiodarone

Answer

Digoxin

Answer

Verapamil

Answer

Propranolol

Question 5

What are the characteristic features of a fungal corneal ulcer?

Accepted Answer

Dry ulcer

Answer

Symptoms disproportionate to signs

Answer

Diffuse corneal edema

Answer

All of the above

Question 6

What is the characteristic color of fluorescein staining in a corneal ulcer?

Accepted Answer

Green

Answer

Yellow

Answer

Blue

Answer

Royal blue

Question 7

Which of the following are features of a fungal corneal ulcer?

Accepted Answer

Hyphenated margins

Answer

Symptoms more than signs

Answer

Dry ulcer

Answer

Diffuse corneal edema

Question 8

Which of the following stains is used in granular dystrophy of the cornea?

Accepted Answer

Masson's trichrome

Answer

Congo-red

Answer

Colloidal iron

Answer

PAS

Question 9

Hutchinson's rule is related to which of the following conditions?

Accepted Answer

Herpes zoster ophthalmicus

Answer

Herpes simplex keratitis

Answer

Mycotic keratitis

Answer

None of the above

Question 10

True about Fuchs endothelial dystrophy are all except?

Accepted Answer

Symmetrical and bilateral condition

Answer

Commonly seen in the elderly female

Answer

Cornea guttatae is characteristic

Answer

Patient typically complains of seeing halos in the morning

Diseases of the Cornea — MCQs

Diseases of the Cornea — MCQs

On this page

Practice by Chapter

Want unlimited practice?