Glaucoma Practice Questions

Q: Latanoprost is used in the treatment of which condition?

Open angle glaucoma. **Explanation:** **Latanoprost** is a **Prostaglandin F2α (PGF2α) analogue** and is currently considered the first-line medical therapy for **Primary Open Angle Glaucoma (POAG)** and Ocular Hypertension. **Why Option A is correct:** The primary mechanism of Latanoprost is increasing the **uveoscleral outflow** of aqueous humor. It achieves this by remodeling the extracellular matrix in the ciliary muscle, thereby reducing resistance to drainage. In POAG, where the trabecular meshwork is dysfunctional but the angle remains open, enhancing this alternative drainage pathway effectively lowers Intraocular Pressure (IOP). **Why other options are incorrect:** * **Option B (Angle Closure Glaucoma):** The definitive treatment for primary angle closure is surgical or laser intervention (e.g., Laser Peripheral Iridotomy). While PG analogues can be used as adjunctive therapy after the angle is opened, they are not the primary or specific treatment for the closure itself. * **Options C & D (Uveitis):** Latanoprost is generally **avoided** in patients with active uveitis. Prostaglandins are pro-inflammatory mediators; using them can exacerbate intraocular inflammation and increase the risk of developing **Cystoid Macular Edema (CME)**. **High-Yield Clinical Pearls for NEET-PG:** * **Dosage:** Administered as once-daily drops (usually at bedtime). * **Side Effects (Highly examinable):** 1. **Hypertrichosis:** Increased length and thickness of eyelashes. 2. **Iris Heterochromia:** Permanent darkening of the iris (increased melanin production). 3. **Periorbitopathy:** Loss of periorbital fat (sunken eyes). * **Contraindications:** History of Herpetic Keratitis (may reactivate the virus) and active uveitis.

Q: Ocular hypertension carries a high risk of progression to open-angle glaucoma. All of the statements given below are associated with the progression, except?

Corneal thickness has no correlation with the progression.. This question tests your knowledge of the **Ocular Hypertension Treatment Study (OHTS)**, a landmark trial that identified risk factors for the conversion of Ocular Hypertension (OHT) to Primary Open-Angle Glaucoma (POAG). ### **Why Option A is the Correct Answer (The False Statement)** Central Corneal Thickness (CCT) is one of the **most significant predictors** of progression. A **thin cornea** (typically <555 µm) is strongly associated with an increased risk of developing glaucoma. This is because: 1. **Measurement Error:** Goldmann Applanation Tonometry underestimates IOP in thin corneas, leading to a "false low" reading. 2. **Biological Factor:** Thin corneas may reflect a structurally weaker lamina cribrosa, making the optic nerve more susceptible to pressure damage. ### **Analysis of Other Options** * **Option B (Myopia):** High myopia is a well-established risk factor for POAG due to structural changes in the optic nerve head and an elongated axial length. * **Option C (IOP Control):** The OHTS trial proved that lowering IOP by 20% (using topical medications) reduced the risk of progression from 9.5% to 4.4% over five years. * **Option D (Race):** While glaucoma affects all races, the OHTS and other studies indicate that **African Americans** and **Caucasians** have a higher risk of progression compared to other groups, with African Americans often presenting with thinner corneas and earlier onset. ### **NEET-PG High-Yield Pearls** * **OHT Definition:** IOP >21 mmHg, normal optic disc, normal visual fields, and open angles. * **Key Risk Factors for Progression (OHTS):** 1. Higher IOP 2. Older Age 3. **Thin Central Corneal Thickness (CCT)** 4. Increased Vertical Cup-to-Disc Ratio (VCDR) 5. Higher Pattern Standard Deviation (PSD) on perimetry. * **Formula:** For every 40 µm decrease in CCT, there is a 70% increased risk of developing glaucoma.

Q: Which of the following procedures involves the use of a glaucoma drainage device?

Seton operation. **Explanation:** **Correct Answer: D. Seton operation** The **Seton operation** refers to the surgical implantation of a **Glaucoma Drainage Device (GDD)** or aqueous shunt. These devices (e.g., Ahmed Glaucoma Valve, Baerveldt, or Molteno implants) consist of a tube inserted into the anterior chamber that drains aqueous humor to an external plate fixed to the sclera. This creates a permanent pathway for fluid to bypass the trabecular meshwork. It is typically indicated in "refractory" cases where traditional surgery has failed, such as neovascular glaucoma, uveitic glaucoma, or scarred conjunctiva. **Why the other options are incorrect:** * **A. Viscocanalostomy:** This is a **non-penetrating** glaucoma surgery where viscoelastic material is used to dilate Schlemm’s canal to improve outflow. No hardware or shunt is implanted. * **B. Trabeculectomy:** This is the "gold standard" filtering surgery. It involves creating a fistula to drain aqueous into a subconjunctival **bleb**. While it creates a new drainage pathway, it does not utilize a synthetic drainage device (tube). * **C. Deep sclerectomy:** Another **non-penetrating** procedure where a deep scleral flap is removed to allow aqueous to percolate through the thin trabeculo-descemet’s membrane. No device is used. **High-Yield Clinical Pearls for NEET-PG:** * **Ahmed Valve:** A popular "valved" Seton device that limits hypotony by closing if intraocular pressure (IOP) drops below 8 mmHg. * **Indication:** Setons are the procedure of choice for **Neovascular Glaucoma (NVG)** and **Glaucoma in Aphakia**. * **Complication:** The most common early complication of non-valved Setons is **postoperative hypotony**, while late complications include **tube erosion** or **corneal endothelial loss**.

Q: Angle recession glaucoma occurs in which of the following situations?

Concussion injury of the globe. **Explanation:** **Angle Recession Glaucoma** is a secondary open-angle glaucoma that occurs as a late complication of **blunt (concussion) trauma** to the eye. 1. **Why Option A is Correct:** When the globe undergoes a sudden concussion injury, the force causes a rapid anteroposterior compression and simultaneous equatorial expansion. This hydraulic pressure forces aqueous humor against the iris root and ciliary body. The result is a **tear between the longitudinal and circular muscles of the ciliary body**. While the angle initially appears "wider" (recessed) on gonioscopy, the subsequent scarring and degenerative changes in the trabecular meshwork lead to decreased aqueous outflow and elevated intraocular pressure (IOP), often years after the initial injury. 2. **Why Other Options are Incorrect:** * **Extraction of cataract:** This usually *lowers* IOP in primary angle-closure cases. If glaucoma occurs post-surgery, it is typically due to pupillary block, retained viscoelastic, or inflammation (uveitic glaucoma), not angle recession. * **Goniotomy:** This is a *surgical treatment* for congenital glaucoma where the Barkan’s membrane is incised to improve drainage; it does not cause angle recession. * **Intraocular tumors:** These cause secondary glaucoma via direct invasion of the angle, neovascularization, or anterior displacement of the iris-lens diaphragm. **High-Yield Clinical Pearls for NEET-PG:** * **Gonioscopy Finding:** A characteristic wide ciliary body band (deeper angle) compared to the fellow eye. * **Vossius Ring:** Often seen on the lens capsule, indicating previous blunt trauma. * **Risk:** Only about 5-10% of eyes with >180° of recession develop glaucoma; however, it is often a "bimodal" presentation (early spike or late-onset years later). * **Management:** It is often resistant to medical therapy; trabeculectomy with antimetabolites (Mitomycin-C) may be required.

Q: What is the normal cup-to-disc ratio?

0.3. The **Cup-to-Disc Ratio (CDR)** is a critical clinical measurement used to assess the health of the optic nerve head. It compares the diameter of the "cup" (the central pale depression) to the total diameter of the "optic disc." ### **Explanation of the Correct Answer** * **Option A (0.3):** In a healthy individual, the normal CDR typically ranges from **0.1 to 0.3**. A ratio of 0.3 means the cup occupies 30% of the disc's diameter. While there is physiological variation based on disc size, 0.3 is considered the standard baseline for a healthy eye. ### **Explanation of Incorrect Options** * **Option B (0.6):** A CDR of 0.6 is generally considered **suspicious**. In clinical practice, a ratio >0.5 or an asymmetry between the two eyes of >0.2 is a red flag for Glaucoma (glaucomatous cupping). * **Option C & D (1.2 and 2.4):** These values are physiologically impossible. The cup is a part of the disc; therefore, the ratio cannot exceed **1.0**. A ratio of 1.0 (Total Cupping) represents the end-stage of glaucoma where all nerve fibers are lost. ### **High-Yield Clinical Pearls for NEET-PG** 1. **ISNT Rule:** In a normal disc, the thickness of the neuroretinal rim follows the ISNT rule (**Inferior > Superior > Nasal > Temporal**). Glaucoma often causes thinning of the inferior and superior rims first, breaking this rule. 2. **Large Discs vs. Glaucoma:** Large optic discs naturally have larger cups (physiological cupping). Always correlate CDR with the overall disc size. 3. **Vertical Cupping:** Glaucomatous damage often occurs at the poles, leading to **vertical elongation** of the cup (vertical CDR > horizontal CDR). 4. **Bayoneting Sign:** This occurs when retinal vessels make a sharp "Z" bend as they pass over the sharp edge of a deep cup, highly characteristic of advanced glaucoma.

Q: Which of the following does NOT predispose to angle closure glaucoma?

Flat cornea. To understand the predisposition to **Primary Angle Closure Glaucoma (PACG)**, one must visualize a "crowded" anterior segment. PACG occurs when the iris physically obstructs the trabecular meshwork, a condition favored by specific anatomical dimensions. ### Why "Flat Cornea" is the Correct Answer A **flat cornea** (large radius of curvature) actually increases the volume of the anterior chamber and is generally associated with longer eyeballs (myopia). In contrast, a **steep cornea** (small radius of curvature) is a known risk factor for PACG because it is often associated with a shallower anterior chamber and a more crowded angle. Therefore, a flat cornea is protective rather than predisposing. ### Analysis of Incorrect Options * **Small Cornea (Microcornea):** A smaller corneal diameter (typically <11 mm) results in a smaller anterior segment, forcing the internal structures into a tighter space, which narrows the angle. * **Shallow Anterior Chamber:** This is the hallmark anatomical precursor for PACG. A decreased distance between the corneal endothelium and the iris/lens diaphragm makes pupillary block more likely. * **Short Axial Length:** This is characteristic of **hypermetropic (farsighted) eyes**. In short eyes, the lens is disproportionately large relative to the small globe, pushing the iris forward and narrowing the drainage angle. ### High-Yield Clinical Pearls for NEET-PG * **The "Crowded Eye":** PACG is most common in elderly, hypermetropic females. * **Lens Factor:** As age increases, the lens grows in thickness (phacomorphic component), further shallowing the anterior chamber. * **Trigger:** Mydriasis (pupillary dilation) can precipitate an acute attack by bunching the peripheral iris into the angle. * **Gold Standard Diagnosis:** Gonioscopy (to visualize the angle structures). * **Treatment of Choice:** Laser Peripheral Iridotomy (LPI).

Q: Frequent changes of reading glasses in a 60-year-old male patient is a feature of which of the following conditions?

Primary open-angle glaucoma. **Explanation:** **Primary Open-Angle Glaucoma (POAG)** is the correct answer because "frequent changes of reading glasses" is a classic early symptom of this condition. This occurs due to **increased intraocular pressure (IOP)** causing pressure on the ciliary body. This leads to **ciliary muscle weakness** and a subsequent decrease in the amplitude of accommodation. As the eye loses its ability to focus on near objects faster than normal aging would dictate, the patient requires frequent increases in the power of their presbyopic correction. **Analysis of Incorrect Options:** * **Senile Nuclear Cataract:** This typically causes a "second sight" phenomenon. The increasing density of the nucleus increases the refractive index of the lens, leading to **index myopia**. This may actually allow a presbyopic patient to read *without* glasses temporarily, rather than needing frequent changes. * **Acute Angle-Closure Glaucoma:** This is an ocular emergency presenting with sudden, severe pain, redness, blurred vision, and colored halos. It is not a chronic condition characterized by subtle changes in spectacle power. * **Presbyopia:** While this causes a need for reading glasses, it is a gradual, age-related physiological process. A "frequent" or rapid change in power (e.g., every few months) is pathological and should alert the clinician to POAG. **Clinical Pearls for NEET-PG:** * **Early Symptoms of POAG:** Often asymptomatic ("Silent thief of sight"), but may present with frequent change of glasses, delayed dark adaptation, or mild headaches. * **Triad of POAG:** 1. Raised IOP (>21 mmHg), 2. Optic disc cupping, 3. Characteristic visual field defects (e.g., Bjerrum’s scotoma). * **High-Yield Fact:** In any elderly patient complaining of frequent changes in near vision power, always perform **tonometry** and **fundus examination** to rule out POAG.

Q: Which of the following is not useful in chronic open-angle glaucoma?

Homatropine. **Explanation:** The goal of treating **Chronic Open-Angle Glaucoma (COAG)** is to lower intraocular pressure (IOP) by either decreasing aqueous humor production or increasing its outflow. **Why Homatropine is the correct answer:** Homatropine is a **mydriatic-cycloplegic** (anticholinergic) agent. It works by paralyzing the ciliary muscle and the sphincter pupillae. In the context of glaucoma, mydriatics are generally **contraindicated** or not useful because they can cause pupillary dilation, which potentially crowds the anterior chamber angle. Furthermore, by paralyzing the ciliary muscle, they decrease the tension on the trabecular meshwork, which can actually **reduce** aqueous outflow and increase IOP. Homatropine is primarily used for refraction or treating anterior uveitis, not COAG. **Analysis of incorrect options:** * **Prostaglandin Analogues (e.g., Latanoprost):** These are the **first-line** treatment for COAG. They work by increasing the uveoscleral outflow of aqueous humor. * **Pilocarpine:** A miotic (cholinergic) agent. It contracts the ciliary muscle, which pulls on the scleral spur and opens the spaces in the trabecular meshwork, thereby increasing aqueous outflow. While less commonly used today due to side effects, it is a valid treatment. * **Timolol:** A topical beta-blocker that reduces IOP by **decreasing the production** of aqueous humor from the ciliary body. It remains a mainstay of glaucoma therapy. **High-Yield Clinical Pearls for NEET-PG:** * **Drug of Choice (DOC) for COAG:** Prostaglandin Analogues (most potent, once-daily dosing). * **Mechanism of PG Analogues:** Increase uveoscleral outflow. * **Side effect of PG Analogues:** Iris hyperpigmentation and thickening/lengthening of eyelashes. * **Contraindication for Beta-blockers:** Avoid Timolol in patients with Asthma or Heart Block.

Q: What type of laser is used in laser iridotomy?

Nd Yag laser. **Explanation:** **Nd:YAG (Neodymium-doped Yttrium Aluminum Garnet) laser** is the gold standard for performing a peripheral iridotomy (LPI). It is a **solid-state, photodisruptive laser** that works by creating a localized shockwave to punch a hole through the iris tissue. This creates an alternative pathway for aqueous humor to flow from the posterior to the anterior chamber, effectively bypassing pupillary block in Angle-Closure Glaucoma. **Analysis of Options:** * **Nd:YAG Laser (Correct):** Operates at a wavelength of **1064 nm** (infrared). It is preferred because it is non-thermal and can penetrate even dark, thick irides effectively. * **CO2 Laser:** Primarily used in dermatology and ENT for cutting or vaporizing tissue. It has high water absorption and is not used intraocularly for glaucoma. * **Excimer Laser:** A "cool" ultraviolet laser used in refractive surgeries like **LASIK and PRK** to reshape the cornea by photoablation. * **KTP (Potassium Titanyl Phosphate) Laser:** A frequency-doubled Nd:YAG (532 nm) that produces green light. It is used for photocoagulation (like retinal procedures) but is not the primary choice for iridotomy. **High-Yield Clinical Pearls for NEET-PG:** 1. **Indications:** Primary Angle Closure (PAC), PAC Glaucoma, and the fellow eye of a patient with an acute attack. 2. **Pre-procedure Medication:** **Pilocarpine** is used to stretch the iris (making it thinner and easier to penetrate) and **Apraclonidine/Brimonidine** to prevent post-laser IOP spikes. 3. **Preferred Site:** Usually placed in the superior periphery (11 or 1 o'clock) to be covered by the upper eyelid, preventing "ghost images" or diplopia. 4. **Complication:** The most common immediate complication is a transient **IOP spike** and localized **hyphema** (bleeding from the iris).

Question 1

Latanoprost is used in the treatment of which condition?

Accepted Answer

Open angle glaucoma

Answer

Angle closure glaucoma

Answer

Non-granulomatous uveitis

Answer

Granulomatous uveitis

Question 2

Ocular hypertension carries a high risk of progression to open-angle glaucoma. All of the statements given below are associated with the progression, except?

Accepted Answer

Corneal thickness has no correlation with the progression.

Answer

Myopics have an increased risk for progression.

Answer

Progression can be delayed by controlling intraocular pressure (IOP).

Answer

Progression is seen more commonly in the Caucasian population.

Question 3

Which of the following procedures involves the use of a glaucoma drainage device?

Accepted Answer

Seton operation

Answer

Viscocanalostomy

Answer

Trabeculectomy

Answer

Deep sclerectomy

Question 4

Angle recession glaucoma occurs in which of the following situations?

Accepted Answer

Concussion injury of the globe

Answer

Extraction of the cataract

Answer

Gonioctomy

Answer

Intraocular tumours

Question 5

What is the normal cup-to-disc ratio?

Accepted Answer

0.3

Answer

0.6

Answer

1.2

Answer

2.4

Question 6

Which of the following does NOT predispose to angle closure glaucoma?

Accepted Answer

Flat cornea

Answer

Small cornea

Answer

Shallow anterior chamber

Answer

Short axial length of eyeball

Question 7

Frequent changes of reading glasses in a 60-year-old male patient is a feature of which of the following conditions?

Accepted Answer

Primary open-angle glaucoma

Answer

Senile nuclear cataract

Answer

Acute angle-closure glaucoma

Answer

Presbyopia

Question 8

Which of the following is not useful in chronic open-angle glaucoma?

Accepted Answer

Homatropine

Answer

Prostaglandin analogue

Answer

Pilocarpine

Answer

Timolol

Question 9

What type of laser is used in laser iridotomy?

Accepted Answer

Nd Yag laser

Answer

CO2 laser

Answer

Excimer laser

Answer

KTP laser

Question 10

A 60-year-old woman with primary open-angle glaucoma presents with a specific visual field defect. Which part of the visual field is most resistant to progressive glaucomatous visual field loss?

Accepted Answer

Temporal peripheral vision

Answer

Central vision

Answer

Nasal peripheral vision

Answer

Superior vision

Glaucoma — MCQs

Glaucoma — MCQs

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