Diseases of the Lens Practice Questions

Q: Which of the following conditions does NOT cause ectopia lentis?

Cogan-Reese syndrome. **Explanation:** **Ectopia lentis** refers to the displacement or malposition of the crystalline lens due to the dysfunction or disruption of the ciliary zonules. **Why Cogan-Reese Syndrome is the correct answer:** Cogan-Reese syndrome is a clinical variant of **Iridocorneal Endothelial (ICE) syndrome**. It is characterized by a unilateral proliferative endotheliopathy that leads to iris atrophy, "smudged" iris appearance, and pedunculated iris nodules (mammillations). While it causes secondary glaucoma and corneal edema, it **does not** involve the ciliary zonules or cause lens displacement. **Analysis of incorrect options (Causes of Ectopia Lentis):** * **Marfan’s Syndrome:** The most common systemic cause. It typically causes **superotemporal** subluxation. The zonules are stretched but usually intact. * **Homocystinuria:** An autosomal recessive metabolic disorder. It typically causes **inferonasal** subluxation. Zonules are brittle and completely broken due to a deficiency in cystathionine beta-synthase. * **Sulfite Oxidase Deficiency:** A rare inborn error of sulfur metabolism. It is a classic cause of congenital ectopia lentis associated with severe neurological impairment and seizures. **High-Yield Clinical Pearls for NEET-PG:** 1. **Directional Mnemonics:** Marfan’s = **Up** (High stature, Upward subluxation); Homocystinuria = **Down** (Down and In). 2. **Zonular Integrity:** In Marfan’s, zonules are present (stretched); in Homocystinuria, zonules are absent/disintegrated. 3. **Other Causes:** Weill-Marchesani syndrome (microspherophakia with inferior subluxation), Ehlers-Danlos syndrome, and trauma (the most common overall cause). 4. **ICE Syndrome Triad:** Progressive iris atrophy, Chandler syndrome, and Cogan-Reese syndrome.

Q: Which of the following types of cataract is seen 1-2 years following exposure to radiation?

Posterior subcapsular cataract. **Explanation:** **1. Why Posterior Subcapsular Cataract (PSC) is correct:** Radiation-induced cataract (specifically from X-rays, gamma rays, or infrared) typically manifests as a **Posterior Subcapsular Cataract**. The underlying mechanism involves damage to the dividing germinal epithelial cells at the lens equator. These damaged cells migrate posteriorly toward the pole; because they cannot be shed, they accumulate under the posterior capsule, forming opacities. There is a characteristic **latent period** between exposure and clinical manifestation, typically ranging from **1 to 2 years** (though it can vary based on dosage). **2. Analysis of Incorrect Options:** * **A. Lamellar (Zonular) cataract:** This is the most common type of **congenital cataract**. It involves a specific "zone" or layer of the lens, usually due to a transient metabolic insult during development (e.g., Vitamin D deficiency or maternal hypocalcemia). * **B. Christmas tree cataract:** This is characterized by polychromatic needle-like crystals in the deep cortex. It is highly pathognomonic for **Myotonic Dystrophy**. * **C. Posterior polar cataract:** This is a **congenital** stationary opacity located at the posterior pole. It is surgically significant because the posterior capsule is often very thin or absent in these cases, increasing the risk of rupture during surgery. **3. NEET-PG High-Yield Pearls:** * **Steroid-induced cataract:** Also typically presents as **Posterior Subcapsular Cataract**. * **Glass-blower’s cataract:** Caused by **Infrared radiation**; it is unique because it often involves "true exfoliation" of the anterior capsule. * **Sunflower cataract:** Seen in **Wilson’s disease** (Copper deposition). * **Snowflake cataract:** Seen in **Diabetes Mellitus** (juvenile type). * **Oil droplet cataract:** Seen in **Galactosemia**.

Q: The antero-posterior diameter of the lens is increased in all except?

Morgagnian cataract. **Explanation:** The antero-posterior (AP) diameter of the lens refers to its thickness. In a **Morgagnian cataract**, the cortex undergoes liquefaction, and the dense nucleus sinks to the bottom of the capsular bag. While the lens may appear "milky," the overall volume often remains stable or even decreases as the lens becomes shrunken and hypermature. Therefore, the AP diameter does not typically increase; instead, the lens may become flattened. **Analysis of Options:** * **Intumescent Cataract:** This is characterized by the osmotic imbibition of fluid into the lens fibers. The lens becomes swollen and "swollen-looking," significantly increasing its AP diameter and shallowing the anterior chamber. * **Accommodation:** According to the Helmholtz theory, during accommodation, the ciliary muscle contracts, relaxing the zonules. This allows the elastic lens capsule to assume a more spherical shape, directly increasing the AP diameter and increasing its refractive power. * **Weill-Marchesani Syndrome:** This condition is characterized by **microspherophakia** (small, spherical lenses). Because the lens is spherical rather than the normal biconvex shape, its AP diameter is increased relative to its equatorial diameter. **High-Yield Clinical Pearls for NEET-PG:** * **Microspherophakia** is a hallmark of Weill-Marchesani syndrome (autosomal recessive) and can lead to inverse glaucoma. * **Intumescent cataracts** are a common cause of secondary angle-closure glaucoma (phacomorphic glaucoma) due to the increased AP diameter pushing the iris forward. * In **Morgagnian cataracts**, the hallmark sign is the "sinking nucleus" in a milky cortex; if the capsule leaks, it can lead to **phacolytic glaucoma**.

Q: Extra capsular extraction of the lens is not possible in which of the following conditions?

Lens subluxation. **Explanation:** The core requirement for an **Extracapsular Cataract Extraction (ECCE)**, including modern Phacoemulsification, is a **stable and intact capsular bag** supported by healthy zonules. **Why Lens Subluxation is the Correct Answer:** In lens subluxation, the zonules (suspensory ligaments) are weak or broken. During ECCE, the surgeon removes the anterior capsule and the lens nucleus while leaving the posterior capsule in place. If the zonules are compromised, the entire capsular bag becomes unstable. Attempting ECCE in a subluxated lens risks the entire lens (or its fragments) falling into the vitreous cavity. Therefore, **Intracapsular Cataract Extraction (ICCE)**—where the entire lens along with the intact capsule is removed—or a specialized Pars Plana Lensectomy is indicated instead. **Analysis of Incorrect Options:** * **Immature & Hypermature Cataracts:** These represent stages of cortical/nuclear degeneration. As long as the zonular integrity is maintained, the lens can be safely removed via ECCE. In hypermature cataracts, the capsule may be fragile, but ECCE remains the standard approach. * **Developmental Cataract:** These occur in children/young adults. Since the zonules are typically strong, ECCE (specifically lens aspiration) is the procedure of choice. **High-Yield Clinical Pearls for NEET-PG:** * **Absolute Contraindication for ECCE:** Significant zonular dehiscence (>180 degrees) or lens subluxation. * **Indications for ICCE:** Subluxated/dislocated lens, very hard cataracts where phacoemulsification is risky, and in resource-limited settings. * **Zonular Weakness:** Always suspect in cases of Marfan Syndrome, Homocystinuria, or ocular trauma. * **Modern Management:** For mild subluxation, ECCE can sometimes be performed using a **Capsular Tension Ring (CTR)** to stabilize the bag, but classic subluxation remains a textbook indication for ICCE.

Q: Polychromatic lustre is seen in which of the following conditions?

Complicated cataract. **Explanation:** **Complicated cataract** is the correct answer. This type of cataract occurs as a secondary result of intraocular diseases (like chronic uveitis, high myopia, or retinal detachment). The hallmark clinical feature is **polychromatic lustre**, which refers to a characteristic "rainbow-like" play of colors (red, green, and blue) seen at the posterior pole of the lens. This occurs due to the accumulation of inflammatory debris and metabolic byproducts in the posterior subcapsular region, leading to light interference. **Analysis of Options:** * **Post-radiation cataract:** Typically presents as a posterior subcapsular opacity, often starting as a "granularity" or "doughnut-shaped" opacity, but it lacks the classic polychromatic lustre associated with complicated cataracts. * **Diabetic cataract:** True diabetic cataract (Snowflake cataract) presents as subcapsular milky white opacities. While diabetics are prone to senile cataracts earlier, they do not typically show polychromatic lustre unless associated with chronic uveitis. * **Congenital cataract:** These present with various morphologies (e.g., zonular, blue dot, or sutural) depending on the developmental insult, but they do not exhibit the iridescent lustre of a complicated cataract. **High-Yield Clinical Pearls for NEET-PG:** * **Breadcrumb appearance:** Another classic description for the early stages of a complicated cataract. * **Location:** Complicated cataracts almost always begin in the **posterior subcapsular** region because this is the thinnest part of the lens capsule, making it most vulnerable to toxins from the vitreous or uvea. * **Differential Diagnosis:** If "Steroid-induced cataract" is an option, remember it also presents as posterior subcapsular, but polychromatic lustre remains the pathognomonic sign for **Complicated Cataract**.

Q: Shallow anterior chamber is seen in which of the following conditions?

Intumescent cataract. ### Explanation The depth of the anterior chamber (AC) is significantly influenced by the size and position of the crystalline lens. **1. Why Intumescent Cataract is correct:** In the **intumescent stage**, the lens fibers imbibe fluid (osmotic hydration), causing the lens to become **swollen and globular**. This increased anteroposterior thickness of the lens pushes the iris-lens diaphragm forward, resulting in a **shallow anterior chamber**. This is clinically significant as it can lead to secondary angle-closure glaucoma (Phacomorphic glaucoma). **2. Why the other options are incorrect:** * **A. Mature Cataract:** The lens is completely opaque, but the hydration has stabilized. The lens volume is generally normal, so the AC depth remains normal. * **B. Hypermature Cataract:** In the **Morgagnian** or **Sclerotic** types, the lens loses fluid and shrinks (capsular wrinkling). This causes the iris to fall back, leading to a **deep anterior chamber**. * **C. Incipient Cataract:** This is the earliest stage where small opacities (wedges/sectors) appear. The lens volume does not change significantly at this stage, so the AC depth remains normal. **High-Yield Clinical Pearls for NEET-PG:** * **Phacomorphic Glaucoma:** Caused by an **Intumescent cataract** (swollen lens → shallow AC → angle closure). * **Phacolytic Glaucoma:** Caused by a **Hypermature cataract** (leakage of lens proteins → macrophages clog the trabecular meshwork → deep AC). * **Iris Shadow Test:** Positive in immature/intumescent cataracts; negative in mature cataracts (as no clear cortex remains between the iris and the opacity). * **Deep AC** is also seen in: Aphakia, Posterior dislocation of the lens, and Buphthalmos.

Q: Which of the following drugs can cause cataract?

Dexamethasone. **Explanation** **Correct Option: B. Dexamethasone** Corticosteroids, such as **Dexamethasone**, are a well-documented cause of drug-induced cataracts. The characteristic morphology is a **Posterior Subcapsular Cataract (PSC)**. * **Mechanism:** Steroids interfere with the sodium-potassium pump in the lens epithelium, leading to hydration changes. They also bind to lens proteins (crystallins), causing protein aggregation and opacification. * **Risk Factors:** The development is dose-dependent and duration-dependent. Both systemic (oral/IV) and topical (eye drops) administration can lead to cataract formation, though topical use carries a higher risk for ocular side effects. **Incorrect Options:** * **A. Amikacin:** An aminoglycoside primarily associated with **ototoxicity** and **nephrotoxicity**. In ophthalmology, intravitreal injection can cause macular infarction (retinal toxicity), but not cataracts. * **C. Chloramphenicol:** Known for causing bone marrow suppression (aplastic anemia). Ocularly, it is linked to **optic neuritis** with prolonged use, but not lens opacification. * **D. Penicillin:** A beta-lactam antibiotic that generally lacks significant ocular toxicity. It is not associated with cataract formation. **High-Yield Clinical Pearls for NEET-PG:** 1. **Steroid-Induced Glaucoma:** Steroids also decrease aqueous outflow by increasing resistance in the trabecular meshwork, leading to secondary open-angle glaucoma. 2. **Other Drugs causing Cataract:** Miotics (Pilocarpine), Chlorpromazine (star-shaped anterior opacity), Busulfan, and Amiodarone. 3. **PSC Symptoms:** Patients typically complain of significant **glare** and difficulty reading in bright light due to miosis (pupillary constriction) focusing light directly on the central opacity.

Q: Nuclear drop is seen in which type of cataract?

Posterior polar cataract. **Explanation:** **Posterior Polar Cataract (PPC)** is a congenital anomaly characterized by a dense, white, circular opacity located on the posterior capsule. The **"Nuclear Drop"** sign is a classic morphological feature of PPC where the central opacity appears to "drop" or project forward from the posterior pole into the lens cortex, resembling a stalactite. **Why the correct answer is right:** The hallmark of PPC is its strong adherence to, or even absence of, the central posterior capsule. The "nuclear drop" appearance occurs because the opacified fibers are concentrated at the nodal point of the lens. This is clinically significant because the posterior capsule in these cases is extremely thin and fragile, leading to a high risk of **posterior capsular rupture (PCR)** during surgery. **Why the other options are wrong:** * **Posterior Subcapsular Cataract (PSC):** Presents as a "sandpaper" or "bread-crumb" opacity just in front of the posterior capsule. It is associated with steroid use, diabetes, and radiation, but does not show the nuclear drop sign. * **Conical Cataract:** This refers to the shape of the lens (e.g., Lenticonus), often seen in Alport syndrome, rather than a specific "drop" morphology within the nucleus. * **Congenital Cataract:** This is a broad category. While PPC is a type of congenital cataract, the "nuclear drop" is a specific sign pathognomonic to the *polar* variety. **High-Yield Clinical Pearls for NEET-PG:** * **Surgical Caution:** Hydrodissection is **contraindicated** in PPC to avoid blowing out the fragile posterior capsule; "Hydrodelineation" is the preferred technique. * **Morphology:** Often described as a "bull’s eye" or "concentric rings" appearance on slit-lamp examination. * **Association:** Often bilateral and may be associated with persistent hyperplastic primary vitreous (PHPV).

Q: Which morphological type of cataract is most visually handicapping?

Posterior subcapsular. **Explanation** The correct answer is **Posterior Subcapsular Cataract (PSC)**. **Why it is the most visually handicapping:** PSC is located in the visual axis, specifically at the nodal point of the eye. Because the opacity is situated right in front of the posterior capsule, it causes significant light scattering (glare). Its impact is most severe during **near work** and in **bright light** (daytime). This is because the pupillary reflex causes **miosis** (constriction) in these conditions, forcing light to pass through the central, opaque part of the lens, drastically reducing visual acuity. **Analysis of Incorrect Options:** * **Cortical Cataract:** These typically begin as "cuneiform" (wedge-shaped) opacities in the periphery. Vision remains relatively preserved until the opacities extend centrally into the pupillary area. * **Nuclear Cataract:** This involves gradual hardening and yellowing of the lens nucleus. While it causes a "second sight" phenomenon (myopic shift), the visual decline is usually slow and less debilitating in early stages compared to the central obstruction of PSC. * **Zonular (Lamellar) Cataract:** This is a congenital cataract affecting a specific shell/layer of the lens. While it affects vision, it is stationary and does not typically cause the acute functional handicap seen with acquired PSC. **NEET-PG High-Yield Pearls:** * **Etiology:** PSC is strongly associated with **prolonged systemic or topical steroid use**, diabetes mellitus, and ionizing radiation. * **Clinical Sign:** Patients often complain of **glare** while driving at night or difficulty reading in bright sunlight. * **Nodal Point:** Remember that any opacity at the **posterior nodal point** causes the maximum distortion of the image on the retina.

Question 1

Which of the following conditions does NOT cause ectopia lentis?

Accepted Answer

Cogan-Reese syndrome

Answer

Homocystinuria

Answer

Marfan's syndrome

Answer

Sulfite oxidase deficiency

Question 2

Which of the following types of cataract is seen 1-2 years following exposure to radiation?

Accepted Answer

Posterior subcapsular cataract

Answer

Lamellar cataract

Answer

Christmas tree cataract

Answer

Posterior polar cataract

Question 3

The antero-posterior diameter of the lens is increased in all except?

Accepted Answer

Morgagnian cataract

Answer

Intumescent cataract

Answer

Accommodation

Answer

Weill-Marchesani syndrome

Question 4

Extra capsular extraction of the lens is not possible in which of the following conditions?

Accepted Answer

Lens subluxation

Answer

Hypermature cataract

Answer

Immature cataract

Answer

Developmental cataract

Question 5

Polychromatic lustre is seen in which of the following conditions?

Accepted Answer

Complicated cataract

Answer

Post radiation cataract

Answer

Diabetic cataract

Answer

Congenital cataract

Question 6

Shallow anterior chamber is seen in which of the following conditions?

Accepted Answer

Intumescent cataract

Answer

Mature cataract

Answer

Hypermature cataract

Answer

Incipient cataract

Question 7

Which of the following drugs can cause cataract?

Accepted Answer

Dexamethasone

Answer

Amikacin

Answer

Chloramphenicol

Answer

Penicillin

Question 8

Nuclear drop is seen in which type of cataract?

Accepted Answer

Posterior polar cataract

Answer

Posterior subcapsular cataract

Answer

Conical cataract

Answer

Congenital cataract

Question 9

Which morphological type of cataract is most visually handicapping?

Accepted Answer

Posterior subcapsular

Answer

Cortical

Answer

Nuclear

Answer

Zonular

Question 10

Which of the following factors is not responsible for lens transparency?

Accepted Answer

Hydration

Answer

Avascularity

Answer

Antioxidants

Answer

Aquaporins

Diseases of the Lens — MCQs

Diseases of the Lens — MCQs

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