Glaucoma — MCQs

Glaucoma Indian Medical PG Practice Questions and MCQs

Question 281: What is the initial treatment of buphthalmos?

A. Laser trabeculoplasty
B. Goniotomy (Correct Answer)
C. Topical pilocarpine
D. Carbonic anhydrase inhibitors

Explanation: **Explanation:** **Buphthalmos** (Primary Congenital Glaucoma) occurs due to the failure of the neural crest cells to migrate, leading to the persistence of **Barkan’s membrane** over the trabecular meshwork. This creates a mechanical obstruction to aqueous outflow, resulting in increased intraocular pressure (IOP) and the characteristic enlargement of the globe. **Why Goniotomy is the Correct Answer:** The definitive treatment for congenital glaucoma is **surgical**, as medical therapy is only a temporary measure. **Goniotomy** is the initial procedure of choice when the **cornea is clear**. It involves incising Barkan’s membrane to open the drainage angle. If the cornea is hazy or edematous, preventing a clear view of the angle, **Trabeculotomy** is preferred. **Why Other Options are Incorrect:** * **Laser Trabeculoplasty (ALT/SLT):** This is used in adult open-angle glaucomas to increase outflow through the existing meshwork. It is ineffective in infants due to the structural membrane covering the angle. * **Topical Pilocarpine:** While a miotic, it is generally avoided in children as it can cause paradoxical shallowing of the anterior chamber and has poor efficacy in congenital cases. * **Carbonic Anhydrase Inhibitors (CAIs):** These (e.g., Acetazolamide) are used only as a **pre-operative adjunct** to lower IOP and clear corneal edema before surgery. They do not treat the underlying anatomical defect. **High-Yield Clinical Pearls for NEET-PG:** * **Classic Triad:** Epiphora (tearing), Photophobia, and Blepharospasm. * **Haab’s Striae:** Horizontal or curvilinear breaks in Descemet’s membrane due to corneal stretching. * **Large Corneal Diameter:** Diagnosis is suspected if the horizontal corneal diameter is **>12 mm** before age 1. * **Surgery of choice (Clear Cornea):** Goniotomy. * **Surgery of choice (Hazy Cornea):** Trabeculotomy.

Question 282: Which of the following predisposes to glaucoma, except?

A. Flat cornea
B. Increased length of eyeball (Correct Answer)
C. Angular recession
D. Large size of ciliary body

Explanation: **Explanation:** The question asks for the condition that does **not** predispose to glaucoma. To solve this, one must understand the anatomical risk factors for Angle-Closure Glaucoma (ACG). **1. Why "Increased length of eyeball" is the correct answer:** An increased axial length of the eyeball is the hallmark of **Myopia**. Myopic eyes are generally larger, with deeper anterior chambers and wider iridocorneal angles. Therefore, they are anatomically protected against angle-closure glaucoma. While myopes are at a higher risk for *Open-Angle Glaucoma*, the anatomical configuration of a long eye does not "predispose" to the mechanical obstruction of the angle. **2. Analysis of Incorrect Options:** * **Flat Cornea (Cornea Plana):** A flatter cornea is often associated with a shallower anterior chamber, which crowds the angle and increases the risk of Primary Angle-Closure Glaucoma (PACG). * **Angular Recession:** This refers to a tear between the longitudinal and circular muscles of the ciliary body, usually due to blunt trauma. It is a classic cause of **Secondary Open-Angle Glaucoma** because the scarring and damage to the trabecular meshwork reduce aqueous outflow. * **Large size of ciliary body:** A large or anteriorly positioned ciliary body can push the peripheral iris forward (Plateau Iris Syndrome), leading to mechanical closure of the angle. **Clinical Pearls for NEET-PG:** * **Hypermetropia (Short axial length):** This is a major risk factor for PACG due to a shallow anterior chamber and a relatively large lens. * **Lens changes:** An increase in lens thickness (intumescent cataract) or anterior displacement of the lens predisposes to pupillary block. * **Demographics:** PACG is more common in females (3:1 ratio), elderly patients, and individuals of South East Asian descent.

Question 283: Which of the following is a cause of secondary angle closure glaucoma?

A. Pseudophakia (Correct Answer)
B. Corticosteroid-induced
C. Angle recession glaucoma
D. Congenital glaucoma

Explanation: **Explanation:** **Secondary Angle Closure Glaucoma (SACG)** occurs when the drainage angle is physically obstructed by the iris due to an underlying ocular or systemic condition. **Why Pseudophakia is correct:** In a pseudophakic eye (an eye with an artificial intraocular lens), secondary angle closure can occur via two primary mechanisms: 1. **Pupillary Block:** Adhesions (synechiae) form between the iris and the IOL or the posterior capsule, blocking aqueous flow and causing the iris to bulge forward (iris bombe). 2. **Non-pupillary Block:** Large or malpositioned IOLs can directly push the peripheral iris into the angle. **Analysis of Incorrect Options:** * **B. Corticosteroid-induced:** This is a form of **Secondary Open Angle Glaucoma**. Steroids cause increased resistance to aqueous outflow by inducing structural changes in the trabecular meshwork (increased deposition of glycosaminoglycans). * **C. Angle Recession Glaucoma:** This is a **Secondary Open Angle Glaucoma** caused by blunt trauma. The trauma tears the ciliary body muscles, leading to scarring of the trabecular meshwork over time. * **D. Congenital Glaucoma:** This is a developmental glaucoma caused by **trabeculodysgenesis** (malformation of the angle structures), not a secondary closure of a previously normal angle. **High-Yield Clinical Pearls for NEET-PG:** * **Topiramate** use is a classic "drug-induced" cause of secondary angle closure (due to ciliary body edema). * **Neovascular Glaucoma (NVG)** is a common SACG where a fibrovascular membrane pulls the angle shut (Synechial closure). * **Phacomorphic Glaucoma** is secondary angle closure caused by an intumescent (swollen) cataractous lens. * Distinguishing feature: In SACG, the mechanism is either "pushing" the iris from behind or "pulling" the iris into the angle.

Question 284: Which of the following is a cause of secondary angle closure glaucoma?

A. Pseudophakia (Correct Answer)
B. Corticosteroid-induced
C. Angle recession glaucoma
D. Congenital glaucoma

Explanation: **Explanation:** **Secondary Angle Closure Glaucoma (SACG)** occurs when the drainage angle is physically obstructed by the iris due to an underlying ocular pathology. **Why Pseudophakia is correct:** In a pseudophakic eye (an eye with an artificial intraocular lens), secondary angle closure can occur through two primary mechanisms: 1. **Pupillary Block:** Adhesions (synechiae) form between the iris and the IOL or the posterior capsule, blocking aqueous flow and causing the iris to bulge forward (iris bombe). 2. **Non-pupillary Block:** Large or malpositioned IOLs can directly push the peripheral iris into the angle. **Analysis of Incorrect Options:** * **B. Corticosteroid-induced:** This is a form of **Secondary Open Angle Glaucoma**. Steroids increase resistance to aqueous outflow by causing biochemical changes in the trabecular meshwork (increased glycosaminoglycans). * **C. Angle recession glaucoma:** This is a **Secondary Open Angle Glaucoma** caused by blunt trauma. The trauma tears the ciliary body, but the glaucoma itself arises from subsequent scarring and sclerosis of the trabecular meshwork. * **D. Congenital glaucoma:** This is a developmental glaucoma caused by **trabeculodysgenesis** (malformation of the angle structures), not a secondary closure of a previously normal angle. **High-Yield Clinical Pearls for NEET-PG:** * **Topiramate** (used for migraines) is a classic systemic drug cause of bilateral secondary angle closure due to ciliochoroidal effusion. * **Neovascular Glaucoma (NVG)** is a common SACG where a fibrovascular membrane "pulls" the angle shut (Synechial closure). * **Phacomorphic Glaucoma** is secondary angle closure caused by an intumescent (swollen) cataractous lens.

Question 285: Chronic simple glaucoma is a type of_____ glaucoma?

A. Primary closed angle
B. Primary open angle (Correct Answer)
C. Secondary open angle
D. Secondary closed angle

Explanation: **Explanation:** **Chronic Simple Glaucoma** is the synonymous clinical term for **Primary Open Angle Glaucoma (POAG)**. It is a chronic, progressive optic neuropathy characterized by a triad of: 1. **Open anterior chamber angles** (on gonioscopy). 2. **Characteristic optic disc changes** (cupping). 3. **Corresponding visual field defects** (e.g., arcuate scotoma). The condition is "Primary" because it occurs without an identifiable systemic or ocular cause, and "Open Angle" because the trabecular meshwork is visible, though its microscopic resistance to aqueous outflow is increased, leading to elevated Intraocular Pressure (IOP). **Analysis of Incorrect Options:** * **Option A (Primary Closed Angle):** This involves physical apposition between the iris and the cornea, blocking the drainage angle. It is usually acute or subacute and presents with a shallow anterior chamber. * **Options C & D (Secondary Glaucomas):** These occur due to identifiable pre-existing ocular conditions (e.g., pseudoexfoliation, pigment dispersion, uveitis, or trauma). Chronic simple glaucoma, by definition, lacks these secondary triggers. **Clinical Pearls for NEET-PG:** * **Risk Factors:** Age (>40 years), Family history, Myopia, Diabetes Mellitus, and African race. * **Early Sign:** The earliest visual field defect is often a **Paracentral scotoma** or **Siedel’s sign**. * **Treatment:** Prostaglandin analogues (e.g., Latanoprost) are the first-line medical management. * **Gold Standard Diagnosis:** Goldmann Applanation Tonometry (for IOP) and Humphrey Visual Field analysis.

Question 286: Which of the following is not a feature of acute congestive glaucoma?

A. Deep angle (Correct Answer)
B. Painful condition
C. Vertically oval pupil
D. Increased intraocular pressure

Explanation: **Explanation:** Acute congestive glaucoma (Acute Angle-Closure Glaucoma) is an ocular emergency characterized by a sudden, severe rise in intraocular pressure (IOP) due to the mechanical closure of the anterior chamber angle. **1. Why "Deep Angle" is the correct answer:** The hallmark anatomical predisposition for this condition is a **shallow anterior chamber** and a **narrow angle**. A "deep angle" is characteristic of Open-Angle Glaucoma or certain secondary glaucomas, but it is never a feature of acute congestive glaucoma. In this condition, the iris-corneal contact physically blocks aqueous outflow. **2. Analysis of incorrect options:** * **Painful condition:** This is a classic feature. Patients present with sudden, excruciating ocular pain, often accompanied by nausea, vomiting, and headache (often mistaken for a migraine). * **Vertically oval pupil:** Due to high IOP, the iris sphincter muscle undergoes ischemia and paralysis. This results in a **mid-dilated, vertically oval, and non-reactive pupil**, which is a pathognomonic sign. * **Increased intraocular pressure:** The IOP is typically very high (often 40–70 mmHg), leading to corneal edema and the perception of "halos" around lights. **Clinical Pearls for NEET-PG:** * **Immediate Management:** IV Mannitol (to osmotic dehydrate the vitreous) and topical Pilocarpine (once IOP drops below 40 mmHg to pull the iris away from the angle). * **Definitive Treatment:** Peripheral Iridotomy (usually YAG laser) is the gold standard for both the affected and the fellow (prophylactic) eye. * **Corneal Finding:** "Steamy" or "cloudy" cornea due to epithelial edema. * **Predisposing factors:** Hypermetropia (small eyes), advancing age, and female gender.

Question 287: Gun barrel vision is seen in which of the following conditions?

A. Closed angle glaucoma
B. Papilledema (Correct Answer)
C. Nuclear cataract
D. All of the above

Explanation: **Explanation:** **Gun barrel vision** (also known as tubular vision) refers to a severe constriction of the peripheral visual field, leaving only a small, central circular area of vision intact. **Why Papilledema is correct:** In chronic or secondary optic atrophy resulting from long-standing **Papilledema**, there is progressive destruction of the peripheral nerve fibers. This leads to concentric contraction of the visual field. While central vision is often spared until the terminal stages, the peripheral field is lost, creating the "gun barrel" effect. **Analysis of Incorrect Options:** * **Closed-angle glaucoma:** While advanced glaucoma (specifically Chronic Simple Glaucoma) is a classic cause of tubular vision, acute closed-angle glaucoma typically presents with sudden vision loss, halos, and corneal edema rather than progressive field constriction. * **Nuclear cataract:** This condition causes a "second sight" phenomenon (myopic shift) and central blurring, but it does not cause peripheral field constriction or tubular vision. * **Note on Glaucoma:** It is important to note that **Advanced Open Angle Glaucoma** is actually the most common cause of tubular vision in clinical practice. However, among the specific options provided, Papilledema (leading to post-papilledemic atrophy) is a recognized cause. **Clinical Pearls for NEET-PG:** * **Differential Diagnosis of Tubular Vision:** 1. Advanced Glaucoma (most common). 2. Retinitis Pigmentosa (presents with ring scotoma). 3. Post-papilledemic Optic Atrophy. 4. Hysterical blindness (characterized by a constant field size regardless of distance). 5. Quinine toxicity. * **Key Distinction:** In tubular vision, the central visual acuity often remains 6/6 until the very end stages of the disease.

Question 288: Which statement regarding glaucoma is true?

A. If recognized early, the optic neuropathy of glaucoma is reversible.
B. Topical B-adrenergic antagonists have few if any side effects due to their systemic absorption.
C. The initial symptom of optic neuropathy due to glaucoma is loss of central vision.
D. None of the above. (Correct Answer)

Explanation: ### Explanation The correct answer is **D. None of the above**, as all the provided statements regarding glaucoma are medically inaccurate. **1. Why Option A is incorrect:** Glaucomatous optic neuropathy is characterized by the death of retinal ganglion cells and axonal loss at the optic nerve head. Unlike some other forms of neuropathy, this damage is **irreversible**. Early recognition and treatment can only prevent or slow further progression; it cannot restore lost vision or reverse the cupping of the optic disc. **2. Why Option B is incorrect:** Topical $\beta$-adrenergic antagonists (e.g., Timolol) undergo significant **systemic absorption** via the nasolacrimal duct, bypassing first-pass metabolism. This can lead to serious systemic side effects, including bradycardia, heart block, and bronchospasm. They are strictly contraindicated in patients with asthma, COPD, or second/third-degree heart block. **3. Why Option C is incorrect:** Glaucoma typically presents with **peripheral visual field defects** (e.g., arcuate scotoma, nasal step) in its early and moderate stages. **Central vision is usually preserved** until the very end stage of the disease. This is why glaucoma is often called the "silent thief of sight," as patients remain asymptomatic until significant damage has occurred. --- ### High-Yield Clinical Pearls for NEET-PG: * **Gold Standard for IOP:** Goldmann Applanation Tonometry (GAT). * **First-line Treatment:** Prostaglandin analogues (e.g., Latanoprost) are currently the first-line medical therapy for Primary Open Angle Glaucoma (POAG) due to their superior efficacy and once-daily dosing. * **Earliest Sign:** The earliest clinical sign of glaucoma is often **optic disc changes** (like generalized thinning of the neuroretinal rim), which often precede detectable visual field loss on perimetry. * **ISNT Rule:** In a normal eye, the thickness of the neuroretinal rim follows the order: Inferior > Superior > Nasal > Temporal. A violation of this rule is a strong indicator of glaucomatous damage.

Question 289: Trabecular (conventional) outflow of aqueous humor accounts for what percentage?

A. 90 percent (Correct Answer)
B. 80 percent
C. 70 percent
D. 60 percent

Explanation: **Explanation:** The drainage of aqueous humor from the anterior chamber occurs via two primary pathways. The **Trabecular (Conventional) pathway** is the predominant route, accounting for approximately **90%** of total aqueous outflow. In this pathway, fluid flows through the trabecular meshwork, into the Canal of Schlemm, and eventually enters the episcleral veins. This route is pressure-dependent, meaning the rate of drainage increases as intraocular pressure (IOP) rises. **Analysis of Options:** * **Option A (90%):** Correct. Standard physiological data indicates that the vast majority of aqueous exits via the trabecular route. * **Options B, C, and D:** These are incorrect because they underestimate the contribution of the conventional pathway. The remaining **10%** of aqueous drainage occurs via the **Uveoscleral (Unconventional) pathway**, where fluid passes through the ciliary muscle into the suprachoroidal space. **High-Yield Clinical Pearls for NEET-PG:** 1. **Uveoscleral Pathway:** While it only accounts for 10% of drainage, it is the primary target for **Prostaglandin analogues** (e.g., Latanoprost), which increase outflow through this route. 2. **Resistance Site:** The maximum resistance to aqueous outflow in a normal eye is located at the **juxtacanalicular trabecular meshwork** (the portion closest to the Canal of Schlemm). 3. **Steroid-Induced Glaucoma:** Corticosteroids reduce the permeability of the trabecular meshwork, leading to decreased conventional outflow and increased IOP. 4. **Blood in Schlemm’s Canal:** Can be seen during gonioscopy if episcleral venous pressure exceeds IOP (e.g., in Sturge-Weber Syndrome).

Question 290: Which of the following is NOT a cause of hypotony maculopathy?

A. Perforating corneal ulcer
B. Overfiltering bleb
C. Cyclodialysis
D. Suprachoroidal hemorrhage (Correct Answer)

Explanation: **Explanation:** **Hypotony maculopathy** occurs when intraocular pressure (IOP) drops significantly (usually <6 mmHg), leading to structural collapse of the globe. This results in chorioretinal folds, vascular engorgement, and edema in the macular region, which can cause permanent vision loss. **Why Suprachoroidal Hemorrhage is the Correct Answer:** Suprachoroidal hemorrhage (SCH) involves the accumulation of blood in the suprachoroidal space. This is a **space-occupying lesion** that causes a sudden **increase** in intraocular pressure (acute glaucoma) and a shallowing of the anterior chamber. Because it is associated with high IOP (hypertony) rather than low IOP, it cannot cause hypotony maculopathy. **Analysis of Incorrect Options:** * **Perforating corneal ulcer:** Any full-thickness breach in the globe (trauma or ulcer) leads to the leakage of aqueous humor, causing profound hypotony. * **Overfiltering bleb:** A common complication of trabeculectomy where excessive drainage of aqueous into the subconjunctival space lowers IOP below physiological limits. * **Cyclodialysis:** This involves the separation of the ciliary body from the scleral spur, creating an abnormal drainage pathway for aqueous into the suprachoroidal space, leading to chronic hypotony. **NEET-PG High-Yield Pearls:** * **Definition of Hypotony:** IOP < 6 mmHg. * **Classic Sign:** "Stellate" or radial chorioretinal folds centered at the fovea. * **Common Causes:** Post-surgical leak (most common), cyclodialysis cleft, ciliary body detachment, and pharmacological inhibition of aqueous (e.g., Cidofovir). * **Management:** The primary goal is to identify and fix the source of the leak or over-filtration to restore normal IOP.

Practice by Chapter

Aqueous Humor Dynamics

Practice Questions

Primary Open-Angle Glaucoma

Practice Questions

Primary Angle-Closure Glaucoma

Practice Questions

Secondary Open-Angle Glaucomas

Practice Questions

Secondary Angle-Closure Glaucomas

Practice Questions

Developmental and Congenital Glaucomas

Practice Questions

Medical Management of Glaucoma

Practice Questions

Laser Therapy in Glaucoma

Practice Questions

Glaucoma Filtration Surgery

Practice Questions

Glaucoma Drainage Devices

Practice Questions

Angle Assessment Techniques

Practice Questions

Visual Field Testing in Glaucoma

Practice Questions

Want unlimited practice?

Get full access to all questions, explanations, and performance tracking.

Start For Free

Glaucoma — MCQs

Glaucoma — MCQs

On this page

Practice by Chapter

Want unlimited practice?