Glaucoma Practice Questions

Q: In angle closure glaucoma, what mainly causes obstruction to the outflow of aqueous humor?

Iris. ### Explanation In **Angle Closure Glaucoma (ACG)**, the fundamental pathology is a mechanical obstruction of the drainage angle by the **peripheral iris**. **Why Iris is the Correct Answer:** The primary mechanism involves the iris being pushed or pulled against the trabecular meshwork. In most cases, this is triggered by **pupillary block**, where resistance to aqueous flow from the posterior to the anterior chamber increases pressure behind the iris. This causes the iris to bow forward (**iris bombé**), physically apposing the peripheral iris to the cornea and blocking access to the drainage structures. Therefore, the iris acts as the "door" that closes the "drain." **Why Other Options are Incorrect:** * **Trabecular Meshwork (B):** While this is the site of resistance in *Open Angle Glaucoma (OAG)* due to microscopic degenerative changes, in ACG, the meshwork itself is often healthy but becomes inaccessible because the iris covers it. * **Canal of Schlemm (A) and Scleral Venous Plexus (D):** These are distal components of the outflow pathway. They do not cause the primary obstruction in ACG; they are simply deprived of aqueous because the fluid cannot reach them. **High-Yield Clinical Pearls for NEET-PG:** * **Risk Factors:** Hypermetropia (small eyes), shallow anterior chambers, and increasing age (thickening lens). * **Classic Presentation:** Sudden onset of severe pain, "halos" around lights (due to corneal edema), and a mid-dilated, vertically oval, non-reactive pupil. * **Gold Standard Diagnosis:** **Gonioscopy** is essential to visualize the angle and differentiate between open and closed-angle mechanisms. * **Definitive Treatment:** **Laser Peripheral Iridotomy (LPI)**, which bypasses the pupillary block by creating a hole in the iris.

Q: All of the following causes coloured halos except?

Retinal degeneration. **Explanation:** The phenomenon of **coloured halos** (rainbow-like rings around lights) is primarily caused by the **diffraction of light** as it passes through a hazy or irregular medium in the eye. **Why Retinal Degeneration is the Correct Answer:** Retinal degeneration involves the loss of photoreceptors or atrophy of the retinal pigment epithelium. Since the pathology is located at the **neurosensory level (the "film" of the camera)** and not in the transparent media, it does not cause diffraction. Therefore, it does not produce coloured halos. **Analysis of Incorrect Options:** * **Corneal Edema (Option A):** This is the most common cause (e.g., in Acute Congestive Glaucoma). Fluid accumulation in the corneal epithelium and stroma acts like a diffraction grating, splitting white light into its spectral colors. * **Foreign Body (Option C):** A foreign body on the cornea or within the precorneal tear film disrupts the smooth refractive surface, leading to light scattering and halo formation. * **Steroids (Option D):** Prolonged steroid use is a known risk factor for **Steroid-induced Glaucoma** (causing corneal edema) and **Posterior Subcapsular Cataract**. Both conditions cause light diffraction and subsequent halos. **NEET-PG High-Yield Pearls:** 1. **Fincham’s Test:** Used to differentiate halos of Glaucoma from Cataract. When a stenopaeic slit is moved across the pupil, **glaucomatous halos remain intact**, whereas **cataractous halos break into segments**. 2. **Differential Diagnosis of Halos:** * **Glaucoma:** Due to corneal edema (High IOP). * **Cataract:** Due to irregular refractive indices in the lens. * **Mucus on Cornea:** Halos disappear after blinking or washing the eye. 3. **Order of Colors:** In diffraction halos (like Glaucoma), **blue is innermost** and **red is outermost**.

Q: The image shows findings diagnostic of glaucoma: Cupping of disc, Double angulation of blood vessels (visible in middle), one in steep wall of excavation and second in floor of the cup. Nasal shifting of vessels. Thinning of neural rim on temporal side.

Glaucoma. ***Glaucoma (Correct Answer)*** - The image shows **characteristic findings of glaucomatous optic neuropathy**: significant **cupping of the optic disc** due to retinal ganglion cell loss - **Double angulation of blood vessels** (bayoneting sign) - vessels bend acutely over the steep wall of the cup and again at the floor - **Nasal shifting of vessels** - blood vessels appear to hug the nasal side as the cup expands temporally - **Thinning of the neural rim on temporal side** - violation of ISNT rule (Inferior > Superior > Nasal > Temporal rim thickness in normal discs) - These features together are **pathognomonic for glaucoma** *Optic Atrophy (Incorrect)* - Shows **disc pallor** as the primary feature with loss of pink color - May have cupping but lacks the **characteristic double angulation** and **nasal shifting of vessels** seen in glaucoma - Typically caused by chronic optic nerve damage from various etiologies (ischemia, compression, inflammation) *Physiological Cupping (Incorrect)* - Large cup-to-disc ratio (>0.3) present since birth without pathology - Cup remains **symmetric and uniform** without preferential temporal or vertical rim thinning - No progressive enlargement on follow-up and **normal visual fields** - Lacks the **double angulation, nasal displacement**, and asymmetric rim loss characteristic of glaucomatous cupping *Ischemic Optic Neuropathy (Incorrect)* - Presents acutely with **disc edema** initially (swollen, hyperemic disc) - Later shows **diffuse pallor** rather than excavation/cupping - Typically has **altitudinal visual field defects** rather than the arcuate defects of glaucoma - Does not demonstrate the **progressive cupping with vessel changes** seen in chronic glaucoma

Q: The image shows a funnel shaped anterior chamber (deeper in the center and narrow in the periphery), which is seen in angle closure glaucoma. This is caused by:

Iris bombe. ***Iris bombe*** - **Iris bombe** occurs when there is a 360-degree adhesion between the iris and the lens (or anterior vitreous in aphakic/pseudophakic eyes), preventing aqueous humor from flowing from the posterior chamber to the anterior chamber. - This build-up of aqueous humor in the posterior chamber pushes the entire iris anteriorly, creating a **funnel-shaped anterior chamber** that is deeper centrally and shallow peripherally, leading to angle closure. *Anterior synechiae* - **Anterior synechiae** are adhesions between the iris and the cornea or trabecular meshwork, directly closing the angle. - While they cause **angle closure**, they are a consequence of the iris being pushed forward rather than the primary cause of the iris bowing shown. *Posterior synechiae* - **Posterior synechiae** are adhesions between the iris and the lens, specifically at the pupillary margin. - When these adhesions are 360 degrees, they precisely lead to **iris bombe** by blocking aqueous flow from the posterior to the anterior chamber. *Pupillary block* - **Pupillary block** is the mechanism by which aqueous flow is obstructed at the pupil. - It describes the functional blockage and is the underlying cause for the anatomical manifestation of **iris bombe**.

Q: The image shows a tonometer being used. The principle of this device is ImbertFick's law, which measures IOP by flattening the cornea over a specific area with diameter of 3.06 mm. The values recorded are not influenced by scleral rigidity. What type of tonometry is being demonstrated in the image?

Perkin's applanation tonometry. ***Perkin's applanation tonometry*** - The image clearly depicts a **Perkins handheld applanation tonometer** being used to measure intraocular pressure (IOP) - This portable device works on the **ImbertFick's law principle**, flattening the cornea over **3.06 mm diameter** - **Preferred for bedridden patients, children, or those unable to sit at a slit lamp** - Measurements are **not influenced by scleral rigidity**, making it highly accurate *Goldmann applanation tonometry* - This is the **gold standard** but is **mounted on a slit lamp**, not handheld as shown - Requires patient to be seated at the slit lamp - Uses similar ImbertFick's principle with a prism *Schiotz tonometry* - This is an **indentation tonometer**, not applanation - Uses a **plunger that indents the cornea** - Values **are influenced by scleral rigidity** - Less accurate than applanation methods *Non-contact tonometry (Air-puff)* - Uses a **puff of air** to flatten the cornea, no direct contact - Patient sees the device in front but **no instrument touches the eye** - The image shows **direct contact with the cornea**, ruling this out

Q: A patient with cataract presents with pain and redness of eye. On examination he had deep anterior chamber. What is the diagnosis?

Acute phacolytic glaucoma. ***Acute phacolytic glaucoma*** - This condition occurs when **lens proteins leak** from a mature or hypermature cataract into the aqueous humor, causing an inflammatory reaction and **trabecular meshwork obstruction**, leading to elevated intraocular pressure. - The presence of a **deep anterior chamber** distinguishes it from phacomorphic glaucoma, which is characterized by a shallow anterior chamber due to lens intumescence. *Acute angle closure glaucoma* - This typically presents with a **shallow anterior chamber** as the iris bows forward, blocking the trabecular meshwork. - While it causes pain and redness, the deep anterior chamber described in the patient makes this diagnosis unlikely. *Acute neovascular glaucoma* - This type of glaucoma results from the formation of **new blood vessels** on the iris and in the angle of the anterior chamber, often due to conditions like **diabetic retinopathy** or **retinal vein occlusion**. - There is no mention of such predisposing factors or visible neovascularization in the patient's presentation. *Acute phacomorphic glaucoma* - This condition is caused by the **intumescence (swelling) of a cataractous lens**, which pushes the iris forward, leading to a **shallow anterior chamber** and angle closure. - The patient's presentation of a **deep anterior chamber** rules out phacomorphic glaucoma.

Q: Comment on the diagnosis:

Congenital Glaucoma (Buphthalmos). ***Congenital Glaucoma (Buphthalmos)*** - The image displays enlarged, cloudy corneas and deeply set eyes, characteristic of **buphthalmos**, which is a sign of **congenital glaucoma** in infants and young children. - This condition results from elevated intraocular pressure from birth or early childhood due to developmental abnormalities of the **aqueous outflow system** leading to stretching and enlargement of the eye. - Classic triad: **Epiphora (tearing), photophobia, and blepharospasm** - Examination findings include **increased corneal diameter (>12 mm), corneal edema, and Haab's striae** *Congenital Cataract* - Would present with white pupillary reflex (leukocoria) and opacified lens, not enlarged globes - No corneal clouding or increased eye size - Does not cause buphthalmos *Retinoblastoma* - Presents with leukocoria (white pupillary reflex) - May have strabismus, but does not cause corneal enlargement or clouding - Typically unilateral in most cases *Congenital Corneal Opacity* - May present with cloudy cornea but without globe enlargement - No increased intraocular pressure or stretching of ocular tissues - Corneal size remains normal

Q: Which of the following is incorrect about a 2-yearold child presenting with watering from both eyes?

Nasolacrimal duct malformation. ***Nasolacrimal duct malformation*** - **Nasolacrimal duct malformation is NOT a feature of congenital glaucoma**, making this the incorrect statement. - While **nasolacrimal duct obstruction (NLDO)** can cause watering (epiphora) in infants, it is a separate entity from congenital glaucoma and presents differently. - In NLDO, there is watering **without photophobia, without corneal clouding, and without globe enlargement**. - The watering in **congenital glaucoma** is due to **corneal irritation and photophobia** from elevated intraocular pressure, not from nasolacrimal pathology. - There is no primary association between congenital glaucoma and nasolacrimal duct malformation. *Corneal clouding* - **Corneal clouding** is a classic sign of congenital glaucoma, caused by **corneal edema** secondary to elevated intraocular pressure. - The cloudy appearance results from breaks in **Descemet's membrane** (Haab's striae) and stromal edema. - This is a **correct statement** about congenital glaucoma. *Corneal edema* - **Corneal edema** is a direct consequence of sustained elevated intraocular pressure in congenital glaucoma. - The elevated IOP causes fluid accumulation within the corneal layers, leading to a hazy appearance. - This contributes to the photophobia and tearing seen in these patients. - This is a **correct statement** about congenital glaucoma. *Deep anterior chamber* - A **deep anterior chamber** is a hallmark feature of congenital glaucoma, NOT an incorrect finding. - In infants, elevated IOP causes the pliable eye to stretch, resulting in **buphthalmos** (enlarged globe). - As the cornea bows forward and enlarges (diameter >12mm), the **anterior chamber deepens significantly**. - This is a **correct statement** about congenital glaucoma and would be seen in this 2-year-old child.

Q: Which of the following methods of visual field testing is shown below?

Humphrey analyzer. ***Correct: Humphrey analyzer*** - The image distinctly shows a patient positioned with their head on a **chin rest** and forehead strap, looking into a large, automated machine with a **bowl-shaped perimeter** and an external monitor displaying test results, which is characteristic of a Humphrey Field Analyzer. - This **automated perimetry** device is widely used for quantitative assessment of the visual field, especially for detecting and monitoring **glaucoma** and neurologic conditions. *Incorrect: Bjerrum screen* - The Bjerrum screen is a **manual perimetry** method using a tangent screen, typically made of black felt, where targets are moved manually by the examiner. - This method is older and simpler, primarily used for detecting **central and paracentral scotomas** and would not involve a complex electronic device as pictured. *Incorrect: Goldmann perimeter* - The Goldmann perimeter is a **manual kinetic perimetry** device, characterized by a large white bowl where a light spot is moved by the examiner to map visual field boundaries. - While it uses a bowl, it is operated manually and does not feature the electronic screen and automated components seen in the image. *Incorrect: Lister's perimeter* - The term "Lister's perimeter" is not a standard or commonly recognized method of visual field testing in modern ophthalmology. - There is no widely accepted or used device by this name for perimetry.

Question 1

In angle closure glaucoma, what mainly causes obstruction to the outflow of aqueous humor?

Accepted Answer

Iris

Answer

Canal of Schlemm

Answer

Trabecular meshwork

Answer

Scleral venous plexus

Question 2

All of the following causes coloured halos except?

Accepted Answer

Retinal degeneration

Answer

Corneal edema

Answer

Foreign body

Answer

Steroids

Question 3

An elderly female presents with sudden onset of pain, redness, and decreased vision. On examination, hazy cornea, fixed mid-dilated pupil, and shallow anterior chamber are noted. What is the diagnosis?

Accepted Answer

Acute congestive glaucoma

Answer

Central retinal artery occlusion

Answer

Acute conjunctivitis

Answer

Acute uveitis

Question 4

The image shows findings diagnostic of glaucoma: Cupping of disc, Double angulation of blood vessels (visible in middle), one in steep wall of excavation and second in floor of the cup. Nasal shifting of vessels. Thinning of neural rim on temporal side.

Accepted Answer

Glaucoma

Answer

Optic atrophy

Answer

Physiological cupping

Answer

Ischemic optic neuropathy

Question 5

The image shows a funnel shaped anterior chamber (deeper in the center and narrow in the periphery), which is seen in angle closure glaucoma. This is caused by:

Accepted Answer

Iris bombe

Answer

Anterior synechiae

Answer

Posterior synechiae

Answer

Pupillary block

Question 6

The image shows a tonometer being used. The principle of this device is ImbertFick's law, which measures IOP by flattening the cornea over a specific area with diameter of 3.06 mm. The values recorded are not influenced by scleral rigidity. What type of tonometry is being demonstrated in the image?

Accepted Answer

Perkin's applanation tonometry

Answer

Goldmann applanation tonometry

Answer

Schiotz tonometry

Answer

Non-contact tonometry

Question 7

A patient with cataract presents with pain and redness of eye. On examination he had deep anterior chamber. What is the diagnosis?

Accepted Answer

Acute phacolytic glaucoma

Answer

Acute angle closure glaucoma

Answer

Acute neovascular glaucoma

Answer

Acute phacomorphic glaucoma

Question 8

Comment on the diagnosis:

Accepted Answer

Congenital Glaucoma (Buphthalmos)

Answer

Congenital Cataract

Answer

Retinoblastoma

Answer

Congenital Corneal Opacity

Question 9

Which of the following is incorrect about a 2-yearold child presenting with watering from both eyes?

Accepted Answer

Nasolacrimal duct malformation

Answer

Corneal clouding

Answer

Corneal edema

Answer

Deep anterior chamber

Question 10

Which of the following methods of visual field testing is shown below?

Accepted Answer

Humphrey analyzer

Answer

Bjerrum screen

Answer

Goldmann perimeter

Answer

Lister's perimeter

Glaucoma — MCQs

Glaucoma — MCQs

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