Glaucoma Practice Questions

Q: Which of the following is NOT a triad of congenital glaucoma?

Buphthalmos. The classic clinical presentation of **Primary Congenital Glaucoma (PCG)** is characterized by a specific diagnostic triad. Understanding the distinction between symptoms (what the patient/parent notices) and signs (what the doctor finds) is key to answering this question. ### Why "Buphthalmos" is the Correct Answer While **Buphthalmos** (enlargement of the globe due to high intraocular pressure) is a hallmark clinical **sign** of congenital glaucoma, it is **not** part of the classic symptomatic triad. The triad consists of the three primary irritative symptoms caused by corneal edema and epithelial irritation. ### Explanation of the Triad (Incorrect Options) The classic triad includes: 1. **Photophobia (Option A):** Sensitivity to light is often the earliest symptom. 2. **Hyperlacrimation/Epiphora (Option C):** Excessive tearing occurs due to corneal irritation. 3. **Blepharospasm (Option D):** Involuntary squeezing of the eyelids. These three symptoms occur because the elevated intraocular pressure (IOP) causes stretching of the corneal endothelium and subsequent corneal edema, which irritates the corneal nerve endings. ### Clinical Pearls for NEET-PG * **Buphthalmos:** Occurs because the infant's sclera and cornea are elastic and distend when IOP is >21 mmHg. This is typically seen in children under the age of 3. * **Haab’s Striae:** These are horizontal or curvilinear breaks in the **Descemet’s membrane** due to corneal stretching. They are a pathognomonic sign. * **Large Corneal Diameter:** A diameter >12 mm in an infant is highly suggestive of glaucoma (normal is ~10–10.5 mm). * **Management:** Unlike adult glaucoma, the primary treatment for congenital glaucoma is **surgical** (Goniotomy or Trabeculotomy). Medical therapy is only a temporary measure.

Q: Glaucoma associated with intraocular tumors is due to which of the following mechanisms?

All the above. Secondary glaucoma is a common complication of intraocular tumors (such as Uveal Melanoma or Retinoblastoma). The elevation in intraocular pressure (IOP) is **multifactorial**, involving both open-angle and closed-angle mechanisms. **Explanation of Mechanisms:** * **A. Trabecular block by tumor cells:** This is a common mechanism where the tumor directly sheds cells into the aqueous humor. These cells, along with tumor-associated macrophages (melanomalytic glaucoma) or necrotic debris, physically obstruct the trabecular meshwork, reducing aqueous outflow. * **B. Neovascularization of the angle:** Large or necrotic tumors often release pro-angiogenic factors (like VEGF) due to ischemia. This leads to the formation of a fibrovascular membrane over the angle (Neovascular Glaucoma), which contracts and causes synechial angle closure. * **C. Venous stasis following obstruction to vortex veins:** Large posterior segment tumors can physically compress the vortex veins. This leads to increased venous pressure, congestion of the uveal tract, and subsequent displacement of the lens-iris diaphragm forward, causing secondary angle-closure glaucoma. **Why "All the above" is correct:** Intraocular tumors do not rely on a single pathway; they can cause glaucoma through direct infiltration, biochemical signaling (VEGF), or mechanical displacement/compression. **High-Yield Clinical Pearls for NEET-PG:** * **Most common cause** of glaucoma in a child with Retinoblastoma is **neovascularization of the iris (Rubeosis Iridis)**. * **Ring Melanoma** is a specific variant of ciliary body melanoma that classically presents with refractory glaucoma due to circumferential infiltration of the angle. * In any adult presenting with **unilateral** unexplained glaucoma and a masked fundus, always perform an **ultrasound (B-scan)** to rule out an underlying intraocular malignancy.

Q: All of the following can precipitate an attack of narrow-angle glaucoma except:

Prolonged work in bright light. ### Explanation The fundamental mechanism behind **Acute Angle-Closure Glaucoma (AACG)** is the narrowing of the iridocorneal angle, which leads to pupillary block and a sudden rise in intraocular pressure (IOP). **Why "Prolonged work in bright light" is the correct answer:** Bright light triggers the **pupillary light reflex**, causing **miosis** (constriction of the pupil). Miosis pulls the peripheral iris away from the trabecular meshwork, thereby opening the angle and reducing the risk of an attack. In fact, miotics like Pilocarpine are used therapeutically to manage AACG. **Why the other options are wrong:** * **Mydriatics (B):** Drugs that cause mydriasis (dilation) result in a "bunched up" peripheral iris that blocks the drainage angle. Mid-dilatation is the most dangerous position as it maximizes contact between the iris and the lens (pupillary block). * **Prolonged prone position (A):** Staying in a face-down position for a long duration causes the lens to shift forward due to gravity. This increases iridolenticular contact, promoting pupillary block and shallowing the anterior chamber. * **Emotional upsets (D):** Strong emotions trigger a sympathetic surge, leading to **mydriasis**. This physiological dilation can precipitate an attack in predisposed individuals with narrow angles. **High-Yield Clinical Pearls for NEET-PG:** * **Risk Factors:** Hypermetropia (small eyes), shallow anterior chambers, and increasing age (enlarging lens). * **Classic Presentation:** Sudden ocular pain, "halos" around lights (due to corneal edema), and a semi-dilated, non-reactive pupil. * **Drug of Choice (Immediate):** IV Acetazolamide to lower IOP. * **Definitive Treatment:** Peripheral Iridotomy (usually via YAG laser) to create a bypass for aqueous humor.

Q: What is the value of diurnal variation of intraocular pressure (IOP) above which a diagnosis of glaucoma can be made?

8 mm of Hg. **Explanation:** Intraocular pressure (IOP) is not static; it fluctuates throughout the day following a circadian rhythm, a phenomenon known as **diurnal variation**. In a healthy individual, this variation typically ranges between **2 to 5 mm Hg**, usually peaking in the early morning hours. **Why 8 mm Hg is the correct answer:** In patients with glaucoma, the homeostatic mechanisms regulating aqueous humor dynamics are impaired, leading to wider fluctuations in IOP. A diurnal variation of **more than 8 mm Hg** is considered pathological and is a strong diagnostic indicator of glaucoma, even if individual "spot" readings fall within the statistically normal range (10–21 mm Hg). **Analysis of Incorrect Options:** * **A & B (5 mm Hg and 6 mm Hg):** These values fall within the physiological or borderline range. While a variation of 5–6 mm Hg might be suspicious if other clinical signs are present, it is not diagnostic of glaucoma on its own. * **D (10 mm Hg):** While a 10 mm Hg variation is certainly pathological, the diagnostic threshold established in standard ophthalmology textbooks (like Parsons and Khurana) is 8 mm Hg. Choosing 10 mm Hg would miss earlier diagnostic cases. **High-Yield Clinical Pearls for NEET-PG:** * **Gold Standard for Measurement:** Diurnal variation is best measured using **Goldmann Applanation Tonometry (GAT)** every 3–4 hours over a 24-hour period (Phasing). * **Peak Timing:** In most individuals, IOP is highest in the **early morning (8 AM)** and lowest at night; however, some patients may show an "inverse" pattern. * **Clinical Significance:** Large fluctuations in IOP are an independent risk factor for the progression of visual field defects, even in patients with well-controlled mean IOP.

Q: Which of the following statements is true regarding the given investigation?

Stimulus brightness is constant. ***Stimulus brightness is constant*** - In **automated static perimetry** (Humphrey Field Analyzer), the **stimulus brightness is kept constant** while the **threshold sensitivity** is measured at fixed locations. - This method uses **static stimuli** presented at predetermined points to detect **visual field defects** characteristic of glaucoma. *It is a type of manual perimetry* - **Automated static perimetry** is performed using computerized equipment like the **Humphrey Field Analyzer**, not manually. - **Manual perimetry** refers to **Goldmann perimetry**, where the examiner manually controls the stimulus presentation. *A kinetic stimulus is used* - **Static perimetry** uses **stationary stimuli** presented at fixed locations, not moving stimuli. - **Kinetic perimetry** (like **Goldmann perimetry**) uses **moving stimuli** of constant size and brightness to map visual field boundaries. *All of the above* - This option is incorrect since only **"stimulus brightness is constant"** accurately describes automated static perimetry. - The other statements incorrectly describe features of **manual kinetic perimetry** rather than automated static perimetry.

Q: Schwalbe's line is:

The anterior limit of Descemet's membrane. **Explanation:** **Schwalbe’s line** represents the anatomical junction where the corneal endothelium and Descemet’s membrane terminate and the trabecular meshwork begins. It is the most anterior structure visible during **gonioscopy**, appearing as a thin, pearly-white line. 1. **Why Option C is Correct:** Schwalbe’s line is histologically defined as the **anterior limit (peripheral termination) of Descemet’s membrane**. As the cornea transitions into the sclera at the limbus, Descemet’s membrane ends abruptly, forming this landmark. 2. **Why Other Options are Incorrect:** * **Options A & B:** Bowman’s membrane is a superficial layer of the cornea (between the epithelium and stroma). It ends at the limbus but does not form Schwalbe’s line, which is a deep posterior structure. * **Option D:** Descemet’s membrane begins at the corneal periphery (Schwalbe’s line) and covers the posterior surface of the cornea. There is no "posterior limit" in the context of the angle; its termination point is always anterior relative to the drainage structures. **Clinical Pearls for NEET-PG:** * **Gonioscopy Sequence (Anterior to Posterior):** Use the mnemonic **"I Can't See This Stuff"** → **I** (Internal border of Schwalbe’s line), **C** (non-pigmented Trabecular Meshwork), **S** (Scleral spur), **T** (Trabecular meshwork - pigmented), **S** (Ciliary Body Band). * **Sampaolesi Line:** In conditions like Pigment Dispersion Syndrome or Pseudoexfoliation Syndrome, pigment is deposited on or anterior to Schwalbe’s line, creating a "Sampaolesi line." * **Posterior Embryotoxon:** An abnormally thickened and anteriorly displaced Schwalbe’s line, visible on slit-lamp examination without a goniolens. It is a hallmark of Alagille syndrome and Axenfeld-Rieger syndrome.

Q: A young male presents with painless loss of vision and an intraocular pressure of 60mm Hg. Which of the following is the most likely diagnosis?

Glaucomatocyclitic crisis. **Explanation:** The correct answer is **Glaucomatocyclitic crisis (Posner-Schlossman Syndrome)**. This condition is characterized by recurrent episodes of markedly elevated intraocular pressure (IOP), often ranging from 40–60 mmHg, associated with mild anterior chamber inflammation. **Why D is correct:** The hallmark of Posner-Schlossman Syndrome is the **disproportion** between the very high IOP and the lack of symptoms. Unlike acute angle-closure glaucoma, the eye remains "white," and the patient experiences minimal pain or only mild blurring/halos. It typically affects young to middle-aged adults and presents with an open angle on gonioscopy and a few fine, stellate keratic precipitates (KPs). **Why other options are incorrect:** * **A. Angle closure glaucoma:** While IOP can reach 60 mmHg, it is an ocular emergency presenting with severe pain, nausea, vomiting, a "stony hard" eye, and a shallow anterior chamber. It is rarely "painless." * **B. Acute anterior uveitis:** This typically presents with **low** IOP (due to ciliary body exhaustion) or only mildly elevated IOP. It is characterized by significant pain, photophobia, and ciliary congestion. * **C. Chronic papilledema:** This involves optic disc swelling due to increased intracranial pressure. While it causes vision loss, it does not typically cause an elevation in intraocular pressure. **High-Yield Clinical Pearls for NEET-PG:** * **Triad of Posner-Schlossman:** Unilateral high IOP + Open angles + Fine KPs. * **Treatment:** Medical management with topical steroids (to control inflammation) and aqueous suppressants (to lower IOP). Miotics (Pilocarpine) are generally avoided. * **Key differentiator:** If the question mentions "high IOP in a white, quiet eye" in a young patient, always think of Glaucomatocyclitic crisis.

Q: Which of the following tonometers can be used in a diseased cornea?

Tonopen. **Explanation:** The correct answer is **Tonopen**. The underlying medical concept is the principle of **electronic Mackay-Marg tonometry**. Unlike traditional applanation tonometers that require a large, perfectly smooth, and regular corneal surface to satisfy the Imbert-Fick law, the Tonopen uses a micro-strain gauge and a small sensing plunger. Because it has a very small surface area of contact, it can accurately measure Intraocular Pressure (IOP) even on **irregular, scarred, edematous, or diseased corneas**, and it can even be used over bandage contact lenses. **Analysis of Incorrect Options:** * **Schiotz Tonometer:** This is an indentation tonometer. It is highly dependent on **scleral rigidity** and requires a smooth corneal surface for the footplate to rest upon; it is inaccurate in diseased or distorted corneas. * **Maklakov Tonometer:** An early form of applanation tonometry that uses a weighted cylinder and dye. It requires a large area of contact, making it unsuitable for irregular corneal surfaces. * **Perkins Tonometer:** This is essentially a portable version of the **Goldmann Applanation Tonometer (GAT)**. Since it relies on the same biprism principle as GAT, it requires a clear, regular cornea and a stable tear film to visualize the fluorescein mires accurately. **Clinical Pearls for NEET-PG:** * **Gold Standard:** Goldmann Applanation Tonometry (GAT) remains the gold standard for IOP measurement. * **Pneumotonometry:** Another excellent option for irregular corneas (similar to Tonopen). * **Rebound Tonometry (iCare):** Useful in pediatrics as it requires no topical anesthesia. * **Sterilization:** Tonopen uses disposable "Ocu-film" tips, making it ideal for preventing cross-infection (e.g., Epidemic Keratoconjunctivitis).

Q: Haab's striae is seen in which of the following conditions?

Congenital glaucoma. **Explanation:** **Haab’s striae** are a hallmark clinical sign of **Primary Congenital Glaucoma (PCG)**. They represent horizontal or curvilinear breaks in the **Descemet’s membrane** of the cornea. These breaks occur because the infant’s eye is elastic; when intraocular pressure (IOP) rises significantly, the globe stretches (buphthalmos). While the corneal stroma can stretch, the brittle Descemet’s membrane cannot, leading to ruptures that result in permanent linear scars. **Analysis of Options:** * **Congenital Glaucoma (Correct):** The classic triad includes epiphora, photophobia, and blepharospasm. Haab's striae are typically horizontal or concentric to the limbus, distinguishing them from birth trauma (forceps injury), which causes vertical or oblique tears. * **Trachoma:** Characterized by Arlt’s lines (conjunctival scarring) and Herbert’s pits (limbal depressions), not corneal membrane ruptures. * **Scleritis:** An inflammation of the sclera presenting with severe pain and localized or diffuse redness; it does not involve Descemet’s membrane breaks. * **Cataract:** An opacification of the crystalline lens. While congenital cataracts exist, they do not cause the corneal stretching associated with Haab’s striae. **High-Yield Clinical Pearls for NEET-PG:** * **Buphthalmos:** Term for "ox-eye" seen in congenital glaucoma due to increased globe diameter (>12 mm before age 3). * **Haab’s Striae vs. Forceps Injury:** Haab’s = Horizontal/Curvilinear; Forceps = Vertical/Oblique. * **Management:** Unlike adult glaucoma, the primary treatment for congenital glaucoma is **surgical** (Goniotomy or Trabeculotomy). * **Barkan’s Membrane:** A persistent embryonic tissue covering the trabecular meshwork, often implicated in the pathogenesis of PCG.

Question 1

Which of the following is NOT a triad of congenital glaucoma?

Accepted Answer

Buphthalmos

Answer

Photophobia

Answer

Hyperlacrimation

Answer

Blepharospasm

Question 2

Glaucoma associated with intraocular tumors is due to which of the following mechanisms?

Accepted Answer

All the above

Answer

Trabecular block by tumor cells

Answer

Neovascularization of the angle

Answer

Venous stasis following obstruction to vortex veins

Question 3

All of the following can precipitate an attack of narrow-angle glaucoma except:

Accepted Answer

Prolonged work in bright light

Answer

Prolonged prone position

Answer

Mydriatics

Answer

Emotional upsets

Question 4

What is the value of diurnal variation of intraocular pressure (IOP) above which a diagnosis of glaucoma can be made?

Accepted Answer

8 mm of Hg

Answer

5 mm of Hg

Answer

6 mm of Hg

Answer

10 mm of Hg

Question 5

Which of the following statements is true regarding the given investigation?

Accepted Answer

Stimulus brightness is constant

Answer

It is a type of manual perimetry

Answer

A kinetic stimulus is used

Answer

All of the above

Question 6

Schwalbe's line is:

Accepted Answer

The anterior limit of Descemet's membrane

Answer

The anterior limit of Bowman's membrane

Answer

The posterior limit of Bowman's membrane

Answer

The posterior limit of Descemet's membrane

Question 7

A young male presents with painless loss of vision and an intraocular pressure of 60mm Hg. Which of the following is the most likely diagnosis?

Accepted Answer

Glaucomatocyclitic crisis

Answer

Angle closure glaucoma

Answer

Acute anterior uveitis

Answer

Chronic papilledema

Question 8

Which of the following tonometers can be used in a diseased cornea?

Accepted Answer

Tonopen

Answer

Schiotz

Answer

Malkalov

Answer

Perkins

Question 9

What is the mechanism of steroid-induced glaucoma?

Accepted Answer

Inhibition of prostaglandin E (PGE) synthesis

Answer

Narrowing of the angle of the anterior chamber

Answer

Neovascularization of the iris

Answer

Deposition of hemosiderin

Question 10

Haab's striae is seen in which of the following conditions?

Accepted Answer

Congenital glaucoma

Answer

Trachoma

Answer

Scleritis

Answer

Cataract

Glaucoma — MCQs

Glaucoma — MCQs

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