Glaucoma Practice Questions

Q: Campimetry (Scotometry) is performed in the visual field area of:

30 degrees. **Explanation:** **Campimetry**, also known as **Scotometry**, is a method used to evaluate the central portion of the visual field. The correct answer is **30 degrees** because this technique specifically focuses on mapping the central field and identifying scotomas (blind spots) within this range. * **Why 30 degrees is correct:** Campimetry is traditionally performed using a **Bjerrum’s screen** (a black tangential screen). Since most glaucomatous field defects (like Bjerrum’s scotoma, Seidel’s sign, and Paracentral scotomas) manifest within the central 30 degrees, this area is the clinical focus of the test. * **Why other options are incorrect:** * **50, 60, and 90 degrees** refer to the **peripheral visual field**. While the human visual field extends to approximately 90-100 degrees temporally, Campimetry is not designed to measure these peripheral limits. Peripheral fields are instead assessed using **Perimetry** (e.g., Goldmann Perimeter or Automated Humprey Field Analyzer). **Clinical Pearls for NEET-PG:** * **Bjerrum’s Area:** This is the arcuate area located between **10 to 20 degrees** from the fixation point, where early glaucomatous damage is most frequently detected. * **Distance:** Campimetry is typically performed at a distance of **1 meter** or **2 meters** from the screen. * **Isopter:** A line connecting points with the same visual sensitivity. * **Key Difference:** Remember, **Campimetry** = Central 30° (Flat screen); **Perimetry** = Full field (Arc or Bowl-shaped).

Q: Which of the following is NOT a side effect of apraclonidine?

Watering of mouth. **Explanation:** **Apraclonidine** is a selective alpha-2 adrenergic agonist used primarily to prevent or treat post-laser intraocular pressure (IOP) spikes. **Why "Watering of mouth" is the correct answer:** Apraclonidine, like its relative Brimonidine, is a sympathomimetic. A common systemic side effect of alpha-2 agonists is **Xerostomia (dryness of mouth)**, not watering. This occurs due to the activation of alpha-2 receptors in the salivary glands and the central nervous system, which inhibits salivary secretion. **Analysis of incorrect options:** * **Lid dermatitis & Follicular conjunctivitis:** These are common **local allergic reactions** associated with long-term use of topical alpha-agonists. Apraclonidine has a high rate of delayed hypersensitivity (up to 30-40%), which often manifests as blepharoconjunctivitis. * **Eyelid retraction:** This is a unique side effect of Apraclonidine. It occurs because the drug stimulates the alpha-adrenergic receptors of **Müller’s muscle** (a smooth muscle in the upper eyelid), leading to its contraction and subsequent lid elevation. **High-Yield Clinical Pearls for NEET-PG:** * **Mechanism:** Reduces IOP by decreasing aqueous humor production and increasing uveoscleral outflow. * **Tachyphylaxis:** Apraclonidine is notorious for losing its efficacy over time (tachyphylaxis), making it unsuitable for long-term chronic glaucoma management. * **Clinical Use:** It is the drug of choice for preventing IOP spikes after **Nd:YAG laser capsulotomy** or **Laser Peripheral Iridotomy (LPI)**. * **Diagnostic Use:** It is used in the diagnosis of **Horner’s Syndrome**; it causes pupillary dilation in the affected eye (due to denervation supersensitivity) while having no effect on a normal pupil.

Q: On mutation, which of the following may give rise to hereditary glaucoma?

Optineurin. ### Explanation **Correct Answer: A. Optineurin** **Mechanism and Clinical Context:** Glaucoma is a group of optic neuropathies characterized by progressive degeneration of retinal ganglion cells (RGCs). While many cases are sporadic, several genes are linked to hereditary forms. **Optineurin (OPTN)**, located on chromosome 10p13, is a high-yield gene associated primarily with **Normal Tension Glaucoma (NTG)** and some forms of Primary Open Angle Glaucoma (POAG). Optineurin is involved in neuroprotection and vesicular trafficking; mutations lead to increased susceptibility of RGCs to apoptosis, even in the absence of elevated intraocular pressure. **Analysis of Incorrect Options:** * **B. Ephrins:** These are proteins involved in cell signaling, particularly in axon guidance and angiogenesis during embryonic development. They are not linked to the pathogenesis of hereditary glaucoma. * **C. RBA8:** This is not a recognized gene or protein associated with ophthalmic pathology or glaucoma genetics. * **D. Huntingtin:** This protein is encoded by the HTT gene. Mutations (CAG repeats) in this gene cause **Huntington’s Disease**, a neurodegenerative disorder characterized by chorea and cognitive decline, but it is not a cause of glaucoma. **High-Yield Clinical Pearls for NEET-PG:** * **MYOC (Myocilin):** The most common gene mutated in Juvenile Open Angle Glaucoma (JOAG) and adult-onset POAG (Chromosome 1q). * **CYP1B1:** The primary gene associated with **Primary Congenital Glaucoma** (Autosomal Recessive). * **PITX2 and FOXC1:** Associated with Axenfeld-Rieger Syndrome (Anterior segment dysgenesis with secondary glaucoma). * **WDR36:** Another gene linked to adult-onset POAG.

Q: A 55-year-old woman presents with acute pain and redness in her right eye, accompanied by nausea, vomiting, and seeing halos around lights. Examination reveals lacrimation, lid edema, conjunctival injection, a steamy cornea, and a fixed mid-dilated pupil. Her intraocular pressure (IOP) is markedly elevated, and visual acuity in the right eye is 20/200. She has no family history of eye diseases. What is the most likely diagnosis?

Acute closed-angle glaucoma. ### Explanation **1. Why Acute Closed-Angle Glaucoma (ACG) is Correct:** This clinical presentation is a classic medical emergency. ACG occurs when the iris-corneal angle closes abruptly, blocking aqueous humor outflow and causing a rapid rise in intraocular pressure (IOP). * **Key Symptoms:** Sudden severe pain, nausea/vomiting (due to vagal stimulation), and **halos around lights** (caused by corneal edema diffracting light). * **Key Signs:** The **fixed, mid-dilated pupil** is pathognomonic (due to iris sphincter ischemia), accompanied by a **"steamy" or "ground-glass" cornea** (epithelial edema) and ciliary injection. **2. Why the Other Options are Incorrect:** * **Corneal Laceration:** While it causes pain and redness, it typically follows trauma and presents with a shallow anterior chamber or a peaked pupil, not a fixed mid-dilated one. * **Ocular Hypertension:** This refers to elevated IOP (>21 mmHg) *without* optic nerve damage or symptoms. It is an asymptomatic, incidental finding. * **Open-Angle Glaucoma:** This is the "silent thief of sight." It is chronic, painless, and bilateral, characterized by progressive peripheral vision loss rather than an acute symptomatic crisis. **3. NEET-PG High-Yield Pearls:** * **Immediate Management:** Systemic Acetazolamide (to decrease production) and topical Pilocarpine (to induce miosis and open the angle). Note: Pilocarpine is ineffective if IOP >40-50 mmHg due to sphincter ischemia. * **Definitive Treatment:** Peripheral Iridotomy (usually YAG laser) in **both eyes** (the fellow eye is at high risk). * **Risk Factors:** Hypermetropia (small eyes), elderly females, and triggers like darkness (mydriasis) or certain medications (anticholinergics). * **Differential Diagnosis:** Must be distinguished from Acute Ureitis (constricted pupil, normal/low IOP).

Q: Argon laser trabeculoplasty is indicated in which of the following conditions?

Open angle glaucoma. **Explanation:** **Argon Laser Trabeculoplasty (ALT)** is a laser procedure designed to increase aqueous outflow by applying thermal energy to the trabecular meshwork. **Why Option D is Correct:** In **Open Angle Glaucoma (OAG)**, the drainage angle is anatomically open, but there is resistance to aqueous outflow within the trabecular meshwork. ALT works by applying laser burns to the junction of the pigmented and non-pigmented trabecular meshwork. This causes localized tissue contraction, which mechanically "stretches" the adjacent untreated meshwork and opens the Schlemm’s canal, thereby reducing intraocular pressure (IOP). It is typically indicated when medical therapy is insufficient or poorly tolerated. **Why Other Options are Incorrect:** * **A. Aphakic Glaucoma:** This is often complex, involving vitreous incarceration or peripheral anterior synechiae (PAS). The trabecular meshwork is frequently distorted, making ALT ineffective. * **B. Neovascular Glaucoma:** This is caused by a fibrovascular membrane pulling the iris over the angle. Laser treatment to the meshwork cannot overcome this mechanical obstruction; treatment focuses on Panretinal Photocoagulation (PRP) or valves. * **C. Closed Angle Glaucoma:** ALT requires a clear view of the trabecular meshwork. In closed-angle glaucoma, the angle is physically obstructed by the iris, making it impossible to visualize or treat the meshwork with ALT. **High-Yield Clinical Pearls for NEET-PG:** * **Site of Laser:** Junction of the anterior (non-pigmented) and posterior (pigmented) trabecular meshwork. * **Selective Laser Trabeculoplasty (SLT):** A newer alternative to ALT that uses a Q-switched Nd:YAG laser. It is "selective" because it targets only pigmented cells without causing thermal damage, making it repeatable (unlike ALT). * **Contraindication:** ALT is ineffective in **Uveitic Glaucoma** due to the risk of increasing inflammation and further scarring of the angle.

Q: Which instrument is used to visualize the angle of the anterior chamber?

Gonioscopy. **Explanation:** **1. Why Gonioscopy is the Correct Answer:** The angle of the anterior chamber cannot be visualized directly through a slit lamp because of **total internal reflection** at the cornea-air interface. Light rays from the angle strike the cornea at an angle greater than the critical angle (approx. 46°), reflecting back into the eye. A **Goniolens** (e.g., Goldmann 3-mirror or Zeiss 4-mirror) eliminates this air-interface, allowing the clinician to visualize structures like the Schwalbe’s line, Trabecular meshwork, Scleral spur, and Ciliary body band. This is essential for differentiating between Open-Angle and Angle-Closure Glaucoma. **2. Why Other Options are Incorrect:** * **Slit lamp examination:** While used to assess the *depth* of the peripheral anterior chamber (Van Herick’s technique), it cannot visualize the internal structures of the angle itself without a specialized lens. * **Keratometry:** This measures the curvature of the anterior corneal surface, primarily used for IOL power calculation and astigmatism assessment. * **Indirect ophthalmoscopy:** This is used for a wide-field examination of the posterior segment (retina and vitreous), not the anterior chamber angle. **3. Clinical Pearls for NEET-PG:** * **Gold Standard:** Gonioscopy remains the clinical gold standard for angle evaluation. * **Van Herick Technique:** A screening method using a slit lamp to estimate angle width before performing gonioscopy. * **Shaffer’s Grading:** The most common system used to grade the angle (Grade 0: Closed; Grade 4: Wide open). * **Direct vs. Indirect Gonioscopy:** Koeppe lens (Direct) provides an upright image (used in surgery); Goldmann/Zeiss (Indirect) provides an inverted image via mirrors.

Q: Increased intraocular pressure along with an enlarged and thick cornea with a large eye may suggest which of the following conditions?

Congenital glaucoma. ### Explanation **1. Why Congenital Glaucoma is Correct:** The clinical triad of increased intraocular pressure (IOP), an enlarged eye (**Buphthalmos**), and a thick, cloudy cornea is pathognomonic for **Congenital Glaucoma** (specifically Primary Congenital Glaucoma). * **Pathophysiology:** In infants, the collagen fibers of the sclera and cornea are elastic. When IOP rises due to maldevelopment of the trabecular meshwork (trabeculodysgenesis), the globe stretches, leading to an increased corneal diameter (>12 mm) and axial length. * **Corneal Changes:** The stretching causes breaks in Descemet’s membrane (**Haab’s striae**), leading to corneal edema and subsequent thickening/opacification. **2. Why the Other Options are Incorrect:** * **Angle-closure Glaucoma:** Typically occurs in adults with **small eyes** (hypermetropia) and shallow anterior chambers. It does not cause enlargement of the globe because the adult sclera is rigid. * **Phacomorphic Glaucoma:** A secondary angle-closure glaucoma caused by an intumescent (swollen) cataractous lens. While it causes high IOP and corneal edema, it does not result in an enlarged eye. * **Phacotopic Glaucoma:** Glaucoma resulting from lens subluxation or dislocation (ectopia lentis). It is not associated with globe enlargement. **3. Clinical Pearls for NEET-PG:** * **Classic Triad:** Epiphora (tearing), Photophobia, and Blepharospasm. * **Buphthalmos:** Termed "Ox-eye" due to the massive enlargement. * **Measurement:** Normal newborn corneal diameter is ~10-10.5 mm. A diameter **>12 mm** is highly suggestive of glaucoma. * **Treatment of Choice:** Surgery is the primary treatment. **Goniotomy** (if the cornea is clear) or **Trabeculotomy/Trabeculectomy** (if the cornea is cloudy). Medical therapy is only a temporary measure.

Question 1

Campimetry (Scotometry) is performed in the visual field area of:

Accepted Answer

30 degrees

Answer

50 degrees

Answer

60 degrees

Answer

90 degrees

Question 2

Which of the following is NOT a side effect of apraclonidine?

Accepted Answer

Watering of mouth

Answer

Lid dermatitis

Answer

Follicular conjunctivitis

Answer

Eyelid retraction

Question 3

What is the treatment of choice in acute congestive glaucoma?

Accepted Answer

Laser iridotomy

Answer

Pilocarpine

Answer

Timolol

Answer

Trabeculoplasty

Question 4

On mutation, which of the following may give rise to hereditary glaucoma?

Accepted Answer

Optineurin

Answer

Ephrins

Answer

RBA8

Answer

Huntingtin

Question 5

A 55-year-old woman presents with acute pain and redness in her right eye, accompanied by nausea, vomiting, and seeing halos around lights. Examination reveals lacrimation, lid edema, conjunctival injection, a steamy cornea, and a fixed mid-dilated pupil. Her intraocular pressure (IOP) is markedly elevated, and visual acuity in the right eye is 20/200. She has no family history of eye diseases. What is the most likely diagnosis?

Accepted Answer

Acute closed-angle glaucoma

Answer

Corneal laceration

Answer

Ocular hypertension without glaucoma

Answer

Open angle glaucoma

Question 6

What is the initial drug of choice for open-angle glaucoma?

Accepted Answer

Beta-blocker

Answer

Pilocarpine

Answer

Anticholinergics

Answer

Physostigmine

Question 7

Argon laser trabeculoplasty is indicated in which of the following conditions?

Accepted Answer

Open angle glaucoma

Answer

Aphakic glaucoma

Answer

Neovascular glaucoma

Answer

Closed angle glaucoma

Question 8

Which instrument is used to visualize the angle of the anterior chamber?

Accepted Answer

Gonioscopy

Answer

Slit lamp examination

Answer

Keratometry

Answer

Indirect ophthalmoscopy

Question 9

A 30-year-old patient presented with a miotic pupil with raised intraocular pressure and normal anterior chamber in one eye, and a hazy cornea with shallow anterior chamber in the fellow eye. What is the most likely diagnosis?

Accepted Answer

Acute anterior uveitis

Answer

Acute congestive glaucoma

Answer

Chronic simple glaucoma

Answer

Endophthalmitis

Question 10

Increased intraocular pressure along with an enlarged and thick cornea with a large eye may suggest which of the following conditions?

Accepted Answer

Congenital glaucoma

Answer

Angle closure glaucoma

Answer

Phacomorphic glaucoma

Answer

Phacotopic glaucoma

Glaucoma — MCQs

Glaucoma — MCQs

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