Diseases of the Cornea Practice Questions

Q: The corneal presentation shown in the image is characteristic of:

Keratoconus. ***Keratoconus*** - The image shows **central corneal thinning** and **conical protrusion** of the cornea, which are pathognomonic features of **keratoconus**. - This progressive corneal ectatic disorder causes irregular **astigmatism** and **myopia** as secondary refractive consequences, leading to progressive blurred vision. - Key diagnostic features include **Vogt's striae**, **Fleischer's ring**, and **Munson's sign** (not visible on standard refraction). *Myopia* - While keratoconus **causes secondary myopia** as a symptom, the question asks for the **primary diagnosis** based on the corneal structural changes. - Simple myopia is a **refractive error** without structural corneal thinning or conical protrusion. - The characteristic **corneal cone shape** and **thinning** distinguish keratoconus from uncomplicated myopia. *Hypermetropia* - Hypermetropia (farsightedness) occurs when the eye is too short or corneal curvature is too flat, causing light to focus behind the retina. - The structural corneal changes (thinning and protrusion) seen in the image are **incompatible** with hypermetropia. - Keratoconus causes myopia and astigmatism, not hypermetropia. *Cataract formation* - Cataracts involve **lens opacity**, not corneal structural changes. - The image demonstrates **corneal pathology** (thinning and ectasia), not lens changes. - Acute hydrops in advanced keratoconus can mimic cataract symptoms but the primary issue remains corneal.

Q: The given image shows presence of:

Arcus senilis. ***Arcus senilis*** - The image clearly displays a **gray-white opaque ring** around the corneal limbus, which is characteristic of arcus senilis. - This ring is formed by **lipid deposits** (cholesterol and phospholipids) in the peripheral cornea. *Horner Tranta's spots with bulbar congestion* - **Horner-Trantas spots** are gelatinous papulae seen at the limbus, typically in allergic conjunctivitis, and are not visible in this image. - While there is some **bulbar congestion** (redness of the conjunctiva), it is a non-specific finding and not the primary feature shown. *Normal eye* - A **normal eye** would not exhibit the prominent gray-white corneal ring seen in the image. - The presence of this distinct deposit indicates an abnormality, specifically lipid deposition. *Herbert's pits* - **Herbert's pits** are characteristic of resolved trachoma, appearing as small, shallow depressions at the limbus after the resorption of limbal follicles. - The image shows a **continuous white ring**, not discrete pits.

Q: What does the given image show?

Please provide the correct option from the given JSON input so I can generate the explanation as per the instructions.

Q: What does the following image show?

Keratoglobus. ***Keratoglobus*** - The image shows a globe that appears **enlarged and thinned peripherally**, along with a clear cornea, which is characteristic of keratoglobus. - This condition is often associated with conditions like **Ehlers-Danlos syndrome** and **osteogenesis imperfecta**, indicating systemic collagen abnormalities. *Limbic keratoconjunctivitis* - This refers to inflammation of the conjunctiva and cornea near the **limbus**, typically associated with vernal keratoconjunctivitis, and would present with papillae or follicles. - It does not cause the generalized corneal thinning and globe enlargement seen in the image. *Keratoconus* - Characterized by **conical protrusion and thinning of the central cornea**, not the generalized thinning and enlargement of the entire globe. - Clinical signs include Vogt's striae, Fleischer's ring, and Munson's sign, which are not explicitly visible in this image. *Striate keratopathy* - Involves **fine lines or folds in Descemet's membrane** resulting from corneal edema or trauma. - This condition does not involve changes in the overall shape or size of the cornea or globe like keratoglobus.

Q: All are true regarding the image shown except:

Vessels end abruptly at the limbus. ***Vessels end abruptly at the limbus*** - This statement is **FALSE** and therefore the correct answer to this "EXCEPT" question. - The image clearly shows **vascularization extending into the cornea**, past the limbus, which is characteristic of corneal neovascularization. - In a healthy eye, the **cornea is avascular**, and blood vessels normally do not extend beyond the limbus into the corneal tissue. *Superficial vascularization of cornea* - This statement is TRUE (therefore incorrect answer for an "EXCEPT" question). - The image displays prominent **red vessels invading the corneal stroma** from the limbus and superficial layers, indicating superficial vascularization. - This suggests an underlying inflammatory process or chronic irritation causing **neovascularization**. *Seen in interstitial keratitis* - This statement is TRUE (therefore incorrect answer for an "EXCEPT" question). - **Interstitial keratitis (IK)** is characterized by inflammation and vascularization of the corneal stroma, often without primary involvement of the epithelium or endothelium. - The image depicts such stromal vascularization and inflammation, making IK a plausible diagnosis. *Branching of vessels in arborescent fashion* - This statement is TRUE (therefore incorrect answer for an "EXCEPT" question). - The blood vessels in the image show a distinct **tree-like branching pattern** as they penetrate the cornea, which is described as an arborescent fashion. - This **specific pattern of vascularization** is often seen in various forms of chronic keratitis.

Q: What does the following image show?

Metaherpetic keratitis. ***Metaherpetic keratitis*** - The image exhibits **diffuse punctate epithelial defects** and **subepithelial haze**, which are characteristic of metaherpetic keratitis. - This condition is a **complication of recurrent HSV keratitis** where epithelial healing is impaired due to chronic inflammation and nerve damage, despite the absence of active viral replication. *HSV keratitis* - Active HSV keratitis, especially in its epithelial form, typically presents as **dendritic ulcers** or **geographic ulcers** with characteristic terminal bulbs, which are not clearly seen here. - While HSV is the underlying cause, the image depicts the chronic, non-replicative sequelae rather than an acute viral infection. *Nummular keratitis* - Nummular keratitis is characterized by **coin-shaped, discrete lesions** in the corneal stroma, often without significant epithelial involvement. - The image shows a more widespread and superficial epithelial and subepithelial process, rather than focal stromal nummular infiltrates. *Marginal keratitis* - Marginal keratitis involves **inflammatory infiltrates located at the corneal periphery**, typically near the limbus. - The findings in the image are more centrally located and diffuse across the cornea, not confined to the periphery.

Q: A patient presents with a painful red eye. Fluorescein staining reveals the lesion shown in the image. What is the diagnosis?

Dendritic keratitis. ***Dendritic keratitis*** - The image exhibits a classic **branching lesion** on the cornea, characteristic of a **dendritic ulcer**. - This specific morphology, often stained with fluorescein, is pathognomonic for active **herpes simplex virus (HSV) keratitis**. *Metaherpetic keratitis* - This typically presents as a **non-dendritic corneal ulcer**, often with a **trophic** or **geographic** appearance, which results from chronic HSV infection and corneal nerve damage. - While it's a complication of HSV, the current image shows an active dendritic lesion, not the sequelae of metaherpetic disease. *Nummular keratitis* - Characterized by **coin-shaped stromal infiltrates** and is often associated with adenoviral infections or other inflammatory conditions, not the branching pattern seen here. - The lesions in nummular keratitis are typically subepithelial or stromal, not epithelial like a dendrite. *Marginal keratitis* - Usually presents as **crescent-shaped infiltrates** near the limbus (corneal edge) and is often caused by a hypersensitivity reaction to staphylococcal toxins or other peripheral corneal inflammations. - This condition does not exhibit the central, branching epithelial defect shown in the image.

Q: A 15-year-old contact lens user presents with severe eye pain for last 3 days. All are correct about the treatment for the condition shown in the patient except:

Neomycin. ***Neomycin*** - **Neomycin** is an **aminoglycoside antibiotic** with activity against **Gram-positive and Gram-negative bacteria** but has **no anti-amoebic activity** against Acanthamoeba. - It would be **completely inappropriate** as treatment for **Acanthamoeba keratitis** and offers **no therapeutic benefit** for this protozoal infection. - This is the **incorrect option** for treating the condition shown. *Propamidine isethionate* - This is an effective **aromatic diamidine** with potent **amoebicidal activity** used as **first-line treatment** for **Acanthamoeba keratitis**. - It is highly effective against **trophozoite forms** and often used in **combination therapy** with biguanides. - Typically used as **0.1% solution** with good corneal penetration. *Polyhexamethylene biguanide (PHMB)* - A **biguanide antiseptic** that is considered **first-line treatment** for **Acanthamoeba keratitis**. - Works by disrupting **cell membranes** of the amoeba and is effective against both **trophozoite and cyst forms**. - Usually used as **0.02% solution** and often combined with propamidine for synergistic effect. *Natamycin* - While primarily an **antifungal polyene antibiotic**, natamycin has demonstrated **anti-amoebic activity** and is used in **Acanthamoeba keratitis treatment protocols**. - Has shown efficacy against **Acanthamoeba trophozoites and cysts** in various studies. - Often used as **5% suspension** and may be included in combination regimens, particularly in cases with suspected fungal co-infection or as adjunctive therapy.

Q: Which complication of the corneal ulcer is shown in the image below?

Anterior staphyloma. ***Anterior staphyloma*** - An anterior staphyloma is characterized by a **bulging of the cornea and/or sclera**, often with iris prolapse, due to increased intraocular pressure and weakening of the corneal tissue following severe inflammation or trauma, as clearly depicted in the image. - The appearance of the affected eye in the image, showing a **dark, bluish, and irregularly bulging cornea**, is highly consistent with an anterior staphyloma, which results from the incarceration and subsequent atrophy of the uveal tissue within a weakened corneal stroma. *Leucoma* - A leucoma refers to a **dense, opaque white scar** on the cornea that significantly impairs vision. - While leucoma is a severe corneal opacity following inflammation or ulceration, it does not typically involve the **bulging or ectasia** of the cornea and iris shown in the image, which is characteristic of staphyloma. *Nebula* - A nebula is a **faint, cloud-like corneal opacity** that is usually barely discernible and causes minimal visual impairment. - This term describes a very mild corneal scar, which is distinctly different from the **prominent, bulging, and dense opacity** seen in the image. *Descemetocele* - A descemetocele is a condition where the **ulceration of the cornea extends down to Descemet's membrane**, which then bulges outwards due to intraocular pressure. - While it involves corneal bulging, a descemetocele specifically refers to **only Descemet's membrane intact and bulging**, whereas an anterior staphyloma involves the entire corneal and often scleral tissue, frequently with iris incorporation, resulting in a distinctly dark, bluish, iris-pigmented appearance as seen in the image.

Q: What does the following image show?

Kayser-Fleischer sign. ***Kayser-Fleischer sign*** - The image displays a **golden-brown or greenish-brown ring** visible circumferentially in the peripheral cornea, which is characteristic of the **Kayser-Fleischer sign**. - This sign is caused by the deposition of **copper in Descemet's membrane** and is pathognomonic for **Wilson's disease**, a disorder of copper metabolism. *Arcus senilis* - **Arcus senilis** presents as a grayish-white or bluish-white ring in the peripheral cornea due to **lipid deposition**, usually symmetrical and bilateral. - It is typically associated with **aging** and is composed of cholesterol and phospholipids, which is distinct from the copper deposits seen in the image. *Krukenberg spindle* - A **Krukenberg spindle** is a vertical, spindle-shaped deposition of **pigment on the corneal endothelium**, primarily found in **pigment dispersion syndrome**. - The appearance in the image is a circumferential ring of discoloration, not a vertical pigment deposit on the endothelium. *Hudson-Stahli line* - A **Hudson-Stahli line** is a **horizontal brown line** in the inferior third of the cornea, at the junction of the middle and lower thirds of the epithelium. - It results from the **deposition of iron pigment** and is typically an age-related benign finding, very different from the copper ring shown.

Question 1

The corneal presentation shown in the image is characteristic of:

Accepted Answer

Keratoconus

Answer

Myopia

Answer

Hypermetropia

Answer

Cataract formation

Question 2

The given image shows presence of:

Accepted Answer

Arcus senilis

Answer

Horner-Trantas spots with bulbar congestion

Answer

Normal eye

Answer

Herbert's pits

Question 3

What does the given image show?

Answer

Nebula

Answer

Leucoma

Answer

Inverse hypopyon

Answer

Pseudohypopyon

Question 4

What does the following image show?

Accepted Answer

Keratoglobus

Answer

Limbic keratoconjunctivitis

Answer

Keratoconus

Answer

Striate keratopathy

Question 5

All are true regarding the image shown except:

Accepted Answer

Vessels end abruptly at the limbus

Answer

Superficial vascularization of cornea

Answer

Seen in interstitial keratitis

Answer

Branching of vessels in arborescent fashion

Question 6

What does the following image show?

Accepted Answer

Metaherpetic keratitis

Answer

HSV keratitis

Answer

Nummular keratitis

Answer

Marginal keratitis

Question 7

A patient presents with a painful red eye. Fluorescein staining reveals the lesion shown in the image. What is the diagnosis?

Accepted Answer

Dendritic keratitis

Answer

Metaherpetic keratitis

Answer

Nummular keratitis

Answer

Marginal keratitis

Question 8

A 15-year-old contact lens user presents with severe eye pain for last 3 days. All are correct about the treatment for the condition shown in the patient except:

Accepted Answer

Neomycin

Answer

Propamidine isethionate

Answer

Polyhexamethylene biguanide

Answer

Natamycin

Question 9

Which complication of the corneal ulcer is shown in the image below?

Accepted Answer

Anterior staphyloma

Answer

Leucoma

Answer

Nebula

Answer

Descemetocele

Question 10

What does the following image show?

Accepted Answer

Kayser-Fleischer sign

Answer

Arcus senilis

Answer

Krukenberg spindle

Answer

Hudson-Stahli line

Diseases of the Cornea — MCQs

Diseases of the Cornea — MCQs

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