NEET-PG 2015 - Ophthalmology Practice Questions

Q: Which mode of ultrasonography is used to measure the axial length of the eyeball?

A-mode Ultrasonography. ***A-mode Ultrasonography*** - **A-mode** (amplitude modulation) ultrasonography is a **one-dimensional** display that measures the distance between structures based on the time it takes for sound waves to reflect. - It is specifically used for **biometry**, such as measuring the axial length of the eyeball for **intraocular lens (IOL) power calculation** prior to cataract surgery. *B-mode Ultrasonography* - **B-mode** (brightness modulation) ultrasonography provides a **two-dimensional** image, displaying the cross-sectional anatomy of organs. - While useful for visualizing ocular structures, it is not primarily used for precise **axial length measurements**. *M-mode Ultrasonography* - **M-mode** (motion mode) ultrasonography displays the **movement** of structures over time in a one-dimensional format. - This mode is typically used in **cardiac imaging** to assess heart valve motion and chamber dimensions, not for static length measurements of the eye. *None of the options* - This option is incorrect because **A-mode ultrasonography** is indeed the gold standard for measuring the axial length of the eyeball. - The other modes (B-mode and M-mode) serve different diagnostic purposes in ultrasonography.

Q: What is the type of cataract associated with Galactosemia?

Oil drop. ***Oil drop*** - This characteristic appearance is caused by the accumulation of **galactitol** in the lens, leading to changes in refractive index. - The "oil drop" cataract is a classic sign of **galactosemia**, often appearing as an early manifestation of the disease. *Snowflake cataract* - This type of cataract is more commonly associated with **diabetes mellitus** rather than galactosemia. - It presents as **fluffy white opacities** that can lead to rapid vision loss. *Blue dot cataract* - This is typically a **congenital stationary cataract** with small, bluish opacities in the peripheral lens. - It is usually **benign** and non-progressive, and not specifically linked to metabolic disorders like galactosemia. *Polychromatic lustre cataract* - This describes the varied, iridescent colors seen in certain types of cataracts, often associated with **complicated cataracts** or those near the lens sutures. - It does not specifically refer to the unique "oil drop" appearance of galactosemic cataracts.

Q: Rosette cataract is seen due to:

Trauma. ***Trauma*** - A **rosette cataract** is a classic sign of **blunt or penetrating ocular trauma**, where the force disrupts the lens fibers, leading to a characteristic star-shaped opacity. - The trauma causes a rapid swelling and opacification of the lens, often in the anterior or posterior subcapsular regions in a flower-petal or stellar pattern. *Copper foreign body* - A **copper foreign body** typically causes a **chalcosis lentis**, characterized by a **sunflower cataract** (deposits in the anterior capsule) due to copper deposition. - This is distinct from a rosette cataract, which forms due to the mechanical disruption of lens integrity rather than elemental deposition. *Diabetes* - **Diabetic cataracts** are typically either **"snowflake" cataracts** (rapidly progressive in younger patients with uncontrolled diabetes) or more commonly **age-related cataracts** that progress faster in diabetic patients. - These are metabolically induced cataracts, not presenting with the characteristic rosette or star-shaped pattern associated with trauma. *Hyperparathyroidism* - **Hyperparathyroidism** can lead to **metabolic cataracts** due to chronic hypercalcemia, which can cause calcium deposition within the lens. - These cataracts are typically described as **punctate cortical or subcapsular opacities**, rather than the distinct rosette shape seen after trauma.

Q: What is the most common etiopathogenetic cause of glaucoma?

Decreased outflow. ***Decreased outflow*** - The most common cause of glaucoma is an **obstruction** or inefficiency in the drainage of **aqueous humor** from the eye, leading to its accumulation. - This reduced outflow results in an increase in **intraocular pressure (IOP)**, which damages the optic nerve. *Raised pressure in episcleral veins* - While elevated episcleral venous pressure can contribute to increased IOP and glaucoma, it is a **less common primary etiopathogenetic mechanism** compared to impaired outflow facility. - Conditions like **Sturge-Weber syndrome** or an **arteriovenous fistula** can cause this, but they are not the typical presentation of primary open-angle glaucoma. *Increased formation of aqueous humour* - An increase in the production of **aqueous humor** is rarely the primary cause of glaucoma. - The eye's regulatory mechanisms usually compensate, or if overproduction occurs, it is an **anatomical issue**, not an outflow issue. *Increased scleral outflow* - Increased **scleral outflow** (also known as uveoscleral outflow, which is a non-conventional drainage pathway) would actually lead to a **decrease** in intraocular pressure, not an increase. - This mechanism is often targeted by certain glaucoma medications (e.g., **prostaglandin analogues**) to lower IOP by facilitating drainage.

Q: Which of the following is NOT a feature of Primary Infantile (Congenital) glaucoma?

Aniridia may be associated. ***Aniridia may be associated*** - **Aniridia** is a congenital absence of the iris that causes **secondary glaucoma**, not primary infantile glaucoma. - Aniridia-associated glaucoma is a distinct entity from primary congenital glaucoma (PCG), which occurs due to isolated developmental abnormalities of the anterior chamber angle. - This is **NOT a feature** of primary infantile glaucoma, making it the correct answer to this negation question. *Treatment includes trabeculotomy* - **Trabeculotomy** or **goniotomy** are the primary surgical treatments for primary infantile glaucoma. - These procedures aim to improve aqueous outflow by incising or opening the trabecular meshwork. - This is a **true feature** of the management of primary infantile glaucoma. *Buphthalmos can occur* - **Buphthalmos** (\"ox eye\") refers to the enlargement of the globe due to elevated intraocular pressure in infants when the sclera is still distensible. - It is a **classic clinical sign** of primary infantile glaucoma, typically occurring before age 3 years. - This is a **characteristic feature** of the condition. *Cornea is typically enlarged and cloudy* - The **cornea becomes enlarged** (increased horizontal corneal diameter >12 mm in newborns) due to stretching from elevated IOP. - **Corneal cloudiness** results from corneal edema and Haab's striae (breaks in Descemet's membrane). - These are **pathognomonic findings** in primary infantile glaucoma.

Q: Which of the following statements about congenital glaucoma is incorrect?

Anterior chamber is shallow. ***Anterior chamber is shallow*** - In congenital glaucoma, the **anterior chamber depth is typically normal or deep**, not shallow. - A shallow anterior chamber is more characteristic of **angle-closure glaucoma**, which is mechanistically different. - This makes the statement incorrect, as congenital glaucoma is associated with a **deep anterior chamber** due to globe enlargement. *Photophobia is most common symptom* - **Photophobia** (sensitivity to light) is indeed one of the classic presenting symptoms in congenital glaucoma. - It forms part of the classic triad: **photophobia, epiphora (tearing), and blepharospasm**. - This occurs due to **increased intraocular pressure** causing corneal edema and irritation. *Thin and blue sclera seen* - The **sclera** can appear thin and blue due to **buphthalmos** (enlargement of the eye) and stretching of the globe. - The stretching allows the underlying **uveal tissue** to show through, giving the characteristic blue appearance. - This is a direct consequence of elevated intraocular pressure in a developing eye. *Haab's Striae may be seen* - **Haab's striae** are **Descemet's membrane tears** that are pathognomonic of congenital glaucoma. - These horizontal or curvilinear breaks occur due to stretching of the cornea from **elevated intraocular pressure**. - They appear as visible linear opacities on corneal examination.

Q: Descemet membrane breach is seen in ?

Congenital glaucoma (Buphthalmos). ***Congenital glaucoma (Buphthalmos)*** - In **congenital glaucoma**, increased intraocular pressure (IOP) in infancy stretches the developing eye, leading to enlargement (buphthalmos) and **Descemet membrane breaches** or ruptures. - These ruptures appear as fine, parallel, or branching lines on the posterior corneal surface, known as **Haab's striae**, which are characteristic signs of this condition. *Angle closure glaucoma* - This condition involves a sudden rise in IOP due to physical obstruction of the **aqueous humor outflow** and does not typically cause Descemet membrane breaks. - Clinical signs include **corneal edema** due to endothelial dysfunction, but not membrane breaches. *Acute Iridocyclitis* - **Acute iridocyclitis** is an inflammatory condition of the iris and ciliary body, primarily causing cells and flare in the anterior chamber. - It does not directly lead to **Descemet membrane breaches** or structural damage like stretching of the cornea. *Subconjunctival hemorrhage* - This condition is characterized by **bleeding under the conjunctiva** and is typically due to ruptured conjunctival blood vessels. - It is a superficial condition that does not involve the cornea or the Descemet membrane.

Q: What condition are miotics the treatment of choice for?

Open-angle glaucoma. ***Open-angle glaucoma*** - Miotics, such as **pilocarpine**, are a classical treatment option for **primary open-angle glaucoma (POAG)**. - They work by **contracting the ciliary muscle**, which opens up the **trabecular meshwork** and increases aqueous humor outflow. - This results in **reduction of intraocular pressure (IOP)**, the primary goal in glaucoma management. - Though less commonly used today due to side effects (brow ache, miosis affecting vision), they remain effective and are particularly useful in patients who cannot tolerate other medications. *Angle closure glaucoma* - Miotics are **contraindicated in acute angle-closure glaucoma** as they can worsen pupillary block during the acute attack. - The initial treatment involves **IOP-lowering agents, systemic medications, and laser iridotomy**, not miotics. - Miotics may have a limited role in chronic angle closure after definitive treatment, but they are NOT the treatment of choice. *Buphthalmos* - This refers to **enlargement of the eyeball** in infants due to congenital glaucoma. - Management primarily involves **surgical intervention** (goniotomy, trabeculotomy) to address the developmental anomalies of the drainage angle. - Medical management alone, including miotics, is insufficient. *Sympathetic ophthalmia* - A rare **bilateral granulomatous panuveitis** following penetrating trauma or surgery to one eye. - Treated with **corticosteroids and immunosuppressive agents**. - Miotics have no role in managing this inflammatory condition.

Q: What is the cause of glaucoma in retinoblastoma?

Neovascularisation. ***Neovascularisation*** - Retinoblastoma leads to **neovascularization of the iris (NVI)** and **angle structures** due to tumor necrosis, ischemia, and release of **angiogenic factors (VEGF)**. - The **neovascular membrane** grows over and obstructs the **trabecular meshwork** and anterior chamber angle, causing **secondary neovascular glaucoma**. - This is the **most characteristic and common mechanism** of glaucoma in advanced retinoblastoma. - Neovascular glaucoma in retinoblastoma is typically **refractory to medical treatment** and indicates poor prognosis. *Blockage of trabecular network* - While tumor cells can directly seed into the anterior chamber and block the trabecular meshwork, this mechanism is **less common** than neovascularization. - This option is also **less specific** as it doesn't identify the underlying pathophysiological process (neovascularization) that is characteristic of retinoblastoma-associated glaucoma. - Direct trabecular blockage by tumor cells typically occurs in advanced disease and often coexists with neovascularization. *Mass effect of the tumour* - The tumor mass itself rarely causes glaucoma through direct mechanical compression of outflow pathways. - Retinoblastoma causes glaucoma primarily through **secondary mechanisms** such as inflammation, neovascularization, or cellular seeding, not simple bulk effect. - Massive tumors may cause angle closure, but this is uncommon compared to neovascular mechanisms. *Lysis of the lens* - **Phacolytic glaucoma** from lens protein leakage is rare in retinoblastoma. - While lens damage can occur with advanced tumors, it is **not a typical or characteristic cause** of glaucoma in retinoblastoma. - The primary mechanisms involve the **tumor-angle-trabecular meshwork axis**, not lens pathology.

Q: What is the primary function of glaucoma drainage devices?

Drain aqueous humour to an external device. **Drain aqueous humour to an external device** - Glaucoma drainage devices create an artificial outflow pathway, channeling excess **aqueous humour** from the anterior chamber to an external reservoir (usually under the conjunctiva) to lower intraocular pressure. - This bypasses the compromised natural drainage system, preventing further damage to the **optic nerve**. *Drain aqueous humour to the posterior segment* - Glaucoma drainage devices are designed to drain aqueous humour from the **anterior segment** (specifically the anterior chamber) of the eye, not the posterior segment. - The posterior segment primarily contains the **vitreous humour**, and drainage to this area is not the intended mechanism for IOP reduction. *Open the trabeculae mechanically* - Glaucoma drainage devices do not mechanically open the **trabecular meshwork**; this is the mechanism of action for procedures like goniotomy or trabeculoplasty. - These devices create an entirely new drainage pathway, bypassing the dysfunctional trabecular meshwork. *Reduce the aqueous secretion by compressing the ciliary epithelium* - Reducing aqueous humour secretion is the mechanism of action for medications like **beta-blockers** or **carbonic anhydrase inhibitors**, which act on the **ciliary epithelium**. - Glaucoma drainage devices focus on increasing outflow, not on reducing the production of aqueous humour.

Question 1

Which mode of ultrasonography is used to measure the axial length of the eyeball?

Accepted Answer

A-mode Ultrasonography

Answer

B-mode Ultrasonography

Answer

M-mode Ultrasonography

Answer

None of the options

Question 2

What is the type of cataract associated with Galactosemia?

Accepted Answer

Oil drop

Answer

Snowflake cataract

Answer

Blue dot cataract

Answer

Polychromatic lustre cataract

Question 3

Rosette cataract is seen due to:

Accepted Answer

Trauma

Answer

Hyperparathyroidism

Answer

Copper foreign body

Answer

Diabetes

Question 4

What is the most common etiopathogenetic cause of glaucoma?

Accepted Answer

Decreased outflow

Answer

Raised pressure in episcleral veins

Answer

Increased formation of aqueous humour

Answer

Increased scleral outflow

Question 5

Which of the following is NOT a feature of Primary Infantile (Congenital) glaucoma?

Accepted Answer

Aniridia may be associated

Answer

Treatment includes trabeculotomy

Answer

Buphthalmos can occur

Answer

Cornea is typically enlarged and cloudy.

Question 6

Which of the following statements about congenital glaucoma is incorrect?

Accepted Answer

Anterior chamber is shallow

Answer

Thin and blue sclera seen

Answer

Photophobia is most common symptom

Answer

Haab's Striae may be seen

Question 7

Descemet membrane breach is seen in ?

Accepted Answer

Congenital glaucoma (Buphthalmos)

Answer

Angle closure glaucoma

Answer

Acute Iridocyclitis

Answer

Subconjunctival hemorrhage

Question 8

What condition are miotics the treatment of choice for?

Accepted Answer

Open-angle glaucoma

Answer

Angle closure glaucoma

Answer

Buphthalmos

Answer

Sympathetic ophthalmia

Question 9

What is the cause of glaucoma in retinoblastoma?

Accepted Answer

Neovascularisation

Answer

Mass effect of the tumour

Answer

Blockage of trabecular network

Answer

Lysis of the lens

Question 10

What is the primary function of glaucoma drainage devices?

Accepted Answer

Drain aqueous humour to an external device

Answer

Drain aqueous humour to the posterior segment

Answer

Open the trabeculae mechanically

Answer

Reduce the aqueous secretion by compressing the ciliary epithelium

NEET-PG 2015 — Ophthalmology