What is the type of cataract associated with Galactosemia?
Rosette cataract is seen due to:
What is the most common etiopathogenetic cause of glaucoma?
Which of the following is NOT a feature of Primary Infantile (Congenital) glaucoma?
Which of the following statements about congenital glaucoma is incorrect?
Descemet membrane breach is seen in ?
What condition are miotics the treatment of choice for?
What is the cause of glaucoma in retinoblastoma?
What is the primary function of glaucoma drainage devices?
A 44-year-old woman presents with sudden painless loss of vision with a history of previous similar episodes. Fundoscopy shows no glow. What could be the possible diagnosis?
NEET-PG 2015 - Ophthalmology NEET-PG Practice Questions and MCQs
Question 31: What is the type of cataract associated with Galactosemia?
- A. Oil drop (Correct Answer)
- B. Snowflake cataract
- C. Blue dot cataract
- D. Polychromatic lustre cataract
Explanation: ***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.
Question 32: Rosette cataract is seen due to:
- A. Hyperparathyroidism
- B. Copper foreign body
- C. Trauma (Correct Answer)
- D. Diabetes
Explanation: ***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.
Question 33: What is the most common etiopathogenetic cause of glaucoma?
- A. Raised pressure in episcleral veins
- B. Decreased outflow (Correct Answer)
- C. Increased formation of aqueous humour
- D. Increased scleral outflow
Explanation: ***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.
Question 34: Which of the following is NOT a feature of Primary Infantile (Congenital) glaucoma?
- A. Aniridia may be associated (Correct Answer)
- B. Treatment includes trabeculotomy
- C. Buphthalmos can occur
- D. Cornea is typically enlarged and cloudy.
Explanation: ***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.
Question 35: Which of the following statements about congenital glaucoma is incorrect?
- A. Thin and blue sclera seen
- B. Anterior chamber is shallow (Correct Answer)
- C. Photophobia is most common symptom
- D. Haab's Striae may be seen
Explanation: ***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.
Question 36: Descemet membrane breach is seen in ?
- A. Angle closure glaucoma
- B. Acute Iridocyclitis
- C. Subconjunctival hemorrhage
- D. Congenital glaucoma (Buphthalmos) (Correct Answer)
Explanation: ***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.
Question 37: What condition are miotics the treatment of choice for?
- A. Angle closure glaucoma
- B. Open-angle glaucoma (Correct Answer)
- C. Buphthalmos
- D. Sympathetic ophthalmia
Explanation: ***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.
Question 38: What is the cause of glaucoma in retinoblastoma?
- A. Neovascularisation (Correct Answer)
- B. Mass effect of the tumour
- C. Blockage of trabecular network
- D. Lysis of the lens
Explanation: ***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.
Question 39: What is the primary function of glaucoma drainage devices?
- A. Drain aqueous humour to the posterior segment
- B. Drain aqueous humour to an external device (Correct Answer)
- C. Open the trabeculae mechanically
- D. Reduce the aqueous secretion by compressing the ciliary epithelium
Explanation: **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 40: A 44-year-old woman presents with sudden painless loss of vision with a history of previous similar episodes. Fundoscopy shows no glow. What could be the possible diagnosis?
- A. Vitreous Hemorrhage (Correct Answer)
- B. Rhegmatogenous Retinal Detachment
- C. Acute Angle-Closure Glaucoma
- D. Fungal Keratitis
Explanation: ***Vitreous Hemorrhage*** - **Painless vision loss** is a hallmark symptom, and **previous similar episodes** suggest a recurrent condition, characteristic of vitreous hemorrhage from fragile vessels. - The **"no glow"** on fundoscopy indicates that light from the ophthalmoscope is unable to reflect off the retina due to something obstructing the clear media, such as blood in the vitreous cavity. *Rhegmatogenous Retinal Detachment* - While it causes **painless vision loss**, patients often report **floaters** or **flashes of light** preceding the detachment, which are not mentioned here. - Fundoscopy in rhegmatogenous retinal detachment would typically show a **grayish, elevated retina**, often with folds, not a complete loss of red reflex or ''no glow.'' *Acute Angle-Closure Glaucoma* - Characterized by **sudden, severe eye pain**, blurred vision, and often a **red eye** with a fixed, mid-dilated pupil. - Fundoscopy would typically reveal a **cupped optic disc** in advanced stages, but the primary finding is elevated intraocular pressure, with a clear vitreous, thus allowing an initial glow. *Fungal Keratitis* - This is an **infection of the cornea** that typically presents with pain, redness, photophobia, and a visible corneal ulcer or infiltrate. - Vision loss is gradual, and fundoscopy would still show a **normal red reflex** unless the corneal opacity is extremely dense, which is not implied by "no glow."