Lens Subluxation and Dislocation Indian Medical PG Practice Questions and MCQs
Practice Indian Medical PG questions for Lens Subluxation and Dislocation. These multiple choice questions (MCQs) cover important concepts and help you prepare for your exams.
Lens Subluxation and Dislocation Indian Medical PG Question 1: Ectopia lentis in a child is seen in which of the following diseases?
- A. Sarcoidosis
- B. Wilson disease
- C. Homocystinuria (Correct Answer)
- D. Alkaptonuria
- E. Marfan syndrome
Lens Subluxation and Dislocation Explanation: ***Homocystinuria***
- Ectopia lentis (lens dislocation) is a characteristic feature of **homocystinuria**, often presenting at a young age.
- The dislocation in homocystinuria is typically **inferomedial (inferonasally)** due to weakened zonular fibers.
- Homocystinuria is an **inborn error of methionine metabolism** with elevated homocysteine levels.
*Marfan syndrome*
- While **Marfan syndrome** is the most common cause of ectopia lentis, the lens typically dislocates **superiorly and temporally**.
- Marfan syndrome is a connective tissue disorder but is not primarily a metabolic disorder like homocystinuria.
- Both conditions can present with ectopia lentis, but the direction of dislocation and associated features differ.
*Sarcoidosis*
- Ocular manifestations of sarcoidosis usually include **uveitis**, **conjunctivitis**, and **retinal vasculitis**, but not typically ectopia lentis.
- Sarcoidosis is a multisystem granulomatous disease and is rare in young children presenting with ectopia lentis.
*Wilson disease*
- **Kayser-Fleischer rings**, which are deposits of copper in the cornea, are pathognomonic for Wilson disease.
- Ocular involvement in Wilson disease does not typically involve ectopia lentis.
*Alkaptonuria*
- This condition is characterized by the accumulation of **homogentisic acid**, leading to **ochronosis** (black pigmentation) in cartilaginous tissues and urine that turns black on standing.
- Ocular manifestations can include scleral pigmentation, but ectopia lentis is not a feature of alkaptonuria.
Lens Subluxation and Dislocation Indian Medical PG Question 2: Which of the following is the most devastating complication of cataract surgery?
- A. Endophthalmitis (Correct Answer)
- B. Optic neuropathy
- C. Retinal detachment
- D. Vitreous loss
Lens Subluxation and Dislocation Explanation: ***Endophthalmitis***
- **Endophthalmitis** is a severe intraocular infection following cataract surgery that can rapidly lead to irreversible vision loss or even loss of the eye if not promptly treated.
- It is considered the most devastating complication due to its acute onset and high potential for **permanent vision impairment**.
*Optic neuropathy*
- While optic neuropathy can cause visual loss, it is a less common direct complication of cataract surgery compared to endophthalmitis.
- It typically results from processes like **ischemia** or severe orbital inflammation, which are rare occurrences immediately post-cataract surgery.
*Retinal detachment*
- **Retinal detachment** is a serious complication, but generally occurs at a lower rate than endophthalmitis and often has a better visual prognosis with timely surgical repair.
- It is a known risk, particularly in patients with pre-existing **myopia** or prior posterior capsular rupture, but not necessarily the *most* devastating.
*Vitreous loss*
- **Vitreous loss** is an intraoperative complication that increases the risk of other issues like retinal detachment, cystoid macular edema, and endophthalmitis but is not, in itself, the most devastating.
- Proper surgical technique and management during the procedure can mitigate many of its long-term sequelae.
Lens Subluxation and Dislocation Indian Medical PG Question 3: Intumescent cataract is associated with which type of glaucoma?
- A. Phacolytic glaucoma
- B. Phacotopic glaucoma
- C. Pseudophakic glaucoma
- D. Phacomorphic glaucoma (Correct Answer)
Lens Subluxation and Dislocation Explanation: ***Phacomorphic glaucoma***
- **Intumescent cataract** refers to a mature or hypermature cataract that has absorbed water, leading to a swollen lens.
- This swelling can cause the lens to push the iris forward, leading to secondary **angle closure glaucoma** due to pupillary block, which is characteristic of phacomorphic glaucoma.
*Phacolytic glaucoma*
- This type of glaucoma is caused by leakage of **high-molecular-weight lens proteins** from a mature or hypermature cataract into the aqueous humor, triggering a macrophagic response and obstruction of the trabecular meshwork.
- It results in an **open-angle glaucoma** and anterior chamber inflammation, unlike the angle closure seen with intumescent cataracts.
*Phacotopic glaucoma*
- This is a rare term and not a recognized distinct category of glaucoma related to lens swelling. It may refer loosely to glaucoma associated with **lens dislocation** or subluxation.
- It does not specifically describe glaucoma caused by an **intumescent cataract**.
*Pseudophakic glaucoma*
- This refers to glaucoma that develops in patients who have undergone **cataract surgery** and have an **intraocular lens (IOL)** implant (pseudophakia).
- It can be caused by various mechanisms post-surgery, such as inflammation, steroid response, or IOL-related issues, but it is not directly associated with the presence of an intumescent natural lens.
Lens Subluxation and Dislocation Indian Medical PG Question 4: Most visually handicapping cataract is:
- A. Rosette cataract
- B. Nuclear cataract
- C. Posterior subcapsular cataract (Correct Answer)
- D. Conical cataract
Lens Subluxation and Dislocation Explanation: ***Posterior subcapsular cataract***
- This type of cataract causes **the most significant visual impairment** due to its location at the posterior pole of the lens, **directly in the visual axis**.
- Symptoms include **severe glare** (especially in bright light when pupil constricts) and **marked difficulty with reading** and near vision tasks, often **disproportionate to the cataract's size**.
- Causes rapid and debilitating visual symptoms compared to other cataract types.
*Rosette cataract*
- Typically forms after **ocular trauma** and is characterized by a flower-petal-shaped opacity.
- While it can impair vision, its severity depends on size and location, and is usually not as visually debilitating as posterior subcapsular cataract.
*Nuclear cataract*
- Involves the **central nucleus** of the lens and causes gradual blurring of vision with possible **myopic shift**.
- Progresses more slowly, allowing better adaptation compared to the sudden, severe glare and near vision loss of posterior subcapsular cataract.
*Conical cataract*
- Refers to **lenticonus**, a conical protrusion of the lens capsule, usually associated with **Alport syndrome**.
- Relatively rare developmental anomaly, not a common form of acquired cataract, and less functionally debilitating than posterior subcapsular cataract.
Lens Subluxation and Dislocation Indian Medical PG Question 5: Which of the following conditions is associated with ectopia lentis?
- A. Homocystinuria (Correct Answer)
- B. Alport syndrome
- C. Lowe syndrome
- D. Sulphite oxidase deficiency
Lens Subluxation and Dislocation Explanation: ***Homocystinuria***
- **Ectopia lentis** (lens dislocation) is a common and characteristic ocular manifestation of homocystinuria.
- The lens typically dislocates **downward and inward**, differentiating it from Marfan syndrome.
*Alport syndrome*
- Characterized by **glomerulonephritis**, **sensorineural hearing loss**, and ocular abnormalities.
- Ocular manifestations include **anterior lenticonus** (which can be mistaken for ectopia lentis in some descriptions), posterior polymorphous corneal dystrophy, and retinal flecks, but not classic ectopia lentis.
*Lowe syndrome*
- Also known as oculocerebrorenal syndrome of Lowe, it primarily affects the **eyes, brain, and kidneys**.
- Ocular features include **congenital cataracts** and glaucoma, but not ectopia lentis.
*Sulphite oxidase deficiency*
- This is a rare metabolic disorder affecting the metabolism of sulfur-containing amino acids, leading to severe neurological symptoms.
- While it can manifest with **cataracts** and **lens subluxation** in some cases, ectopia lentis is more characteristically associated with homocystinuria, and the overall clinical picture of sulphite oxidase deficiency is dominated by severe neurological impairment.
Lens Subluxation and Dislocation Indian Medical PG Question 6: A patient presents with eye ache and difficulty in vision after watching a movie. What will be the first line of management?
- A. Mannitol with Moxifloxacin
- B. Mannitol with Atropine
- C. Mannitol with lubricating eye drops
- D. Mannitol with Pilocarpine (Correct Answer)
Lens Subluxation and Dislocation Explanation: ***Mannitol with Pilocarpine***
- This combination is appropriate for **acute angle-closure glaucoma (AACG)**, which can be triggered by pupillary dilation (e.g., in a dark movie theater). **Mannitol** is an osmotic diuretic that rapidly reduces intraocular pressure.
- **Pilocarpine** is a miotic agent that constricts the pupil, pulling the iris away from the trabecular meshwork and opening the drainage angle to facilitate aqueous humor outflow.
*Mannitol with Moxifloxacin*
- While mannitol helps with intraocular pressure, **Moxifloxacin is an antibiotic** used to treat bacterial infections.
- There is no indication of an ocular infection in this scenario, so an antibiotic would not be the first-line treatment for sudden eye pain and vision difficulty after watching a movie.
*Mannitol with Atropine*
- Adding **Atropine, a cycloplegic agent**, would cause further pupillary dilation, which would worsen acute angle-closure glaucoma and increase intraocular pressure.
- Atropine is contraindicated in AACG and would exacerbate the patient's condition.
*Mannitol with lubricating eye drops*
- While mannitol helps with intraocular pressure, **lubricating eye drops** are used for dry eyes or surface irritation, not for acute angle-closure glaucoma.
- Lubricating drops do not address the underlying pathology of increased intraocular pressure due to angle closure.
Lens Subluxation and Dislocation Indian Medical PG Question 7: In the context of homocystinuria, which direction does the lens typically subluxate?
- A. Inferotemporal
- B. Inferonasal (Correct Answer)
- C. Superonasal
- D. Superotemporal
Lens Subluxation and Dislocation Explanation: ***Inferonasal***
- In **homocystinuria**, the **ectopia lentis** (lens subluxation) often occurs due to weakening of the **zonular fibers**.
- The classic direction for lens subluxation in homocystinuria is **inferior and nasal**.
*Inferotemporal*
- While lens subluxation can occur in various directions, **inferotemporal** is not the classic or most common presentation in homocystinuria.
- This direction is less specific and does not strongly point to homocystinuria as the underlying cause.
*Superonasal*
- **Superonasal** dislocation of the lens is more characteristic of **Marfan syndrome**, which is important to differentiate from homocystinuria.
- This direction helps distinguish different causes of lens ectopia.
*Superotemporal*
- **Superotemporal** lens subluxation is the hallmark of **Marfan syndrome**, a genetic connective tissue disorder.
- This specific finding is crucial for differential diagnosis in patients presenting with lens ectopia.
Lens Subluxation and Dislocation Indian Medical PG Question 8: Lens subluxation is associated with all of the following conditions except:
- A. Congenital syphilis (Correct Answer)
- B. Homocystinuria
- C. Ehlers-Danlos syndrome
- D. Marfan syndrome
Lens Subluxation and Dislocation Explanation: ***Congenital syphilis***
- While congenital syphilis can cause various ocular manifestations like **interstitial keratitis** and **chorioretinitis**, lens subluxation is not a typical association.
- Ocular problems in congenital syphilis are primarily due to **inflammation** rather than connective tissue defects affecting zonular fibers.
*Homocystinuria*
- **Lens subluxation** (ectopia lentis) is a classic feature of homocystinuria, with the lens typically displaced **inferonasally**.
- This condition affects **cystathionine synthase**, leading to accumulation of homocysteine and methionine, causing defective **collagen cross-linking** and **fibrillin** synthesis, which weakens zonular fibers supporting the lens.
*Ehlers-Danlos syndrome*
- Certain types of Ehlers-Danlos syndrome, particularly **type VI (kyphoscoliotic)**, are associated with **lens subluxation** due to defects in connective tissue.
- The syndrome is characterized by **collagen defects**, leading to joint hypermobility, fragile skin, tissue laxity, and weakened ocular zonules.
*Marfan syndrome*
- **Marfan syndrome** is the most common hereditary cause of lens subluxation, with ectopia lentis occurring in approximately **60-80%** of patients.
- The lens typically dislocates **superotemporal** due to mutations in the **FBN1 gene** encoding fibrillin-1, causing weakened zonular fibers.
- Other ocular features include myopia, retinal detachment, and increased axial length.
Lens Subluxation and Dislocation Indian Medical PG Question 9: Windshield wiper syndrome refers to the unpredictable movement of an intraocular lens (IOL) during head motion. Which of the following describes this condition?
- A. Dislocation of Intraocular lens
- B. Posterior capsular opacification
- C. Reaction to lens material
- D. Malposition of lens (Correct Answer)
Lens Subluxation and Dislocation Explanation: ***Malposition of lens***
- **Windshield wiper syndrome** is a classic presentation of an **intraocular lens (IOL)** that is **malpositioned** within the capsular bag or ciliary sulcus.
- The unpredictable oscillating movement of the IOL, mimicking a **windshield wiper**, arises from inadequate support or fixation, particularly when the capsular bag has insufficient integrity.
- This is a specific type of malposition characterized by the **dynamic movement** with head motion rather than static displacement.
*Dislocation of Intraocular lens*
- While IOL dislocation also involves an IOL moving out of its intended position, **dislocation** typically implies a more severe and complete displacement from the capsular bag.
- **Windshield wiper syndrome** specifically highlights the *oscillating movement* of the IOL within its supporting structure, which is characteristic of **malposition** rather than complete dislocation.
- In true dislocation, the IOL typically falls into the vitreous cavity or anterior chamber.
*Posterior capsular opacification*
- **Posterior capsular opacification (PCO)** refers to the clouding of the posterior capsule behind the IOL due to lens epithelial cell proliferation.
- PCO causes gradual vision loss and glare, but it does not involve the physical movement of the IOL itself.
- PCO is a common late complication of cataract surgery but is unrelated to IOL instability.
*Reaction to lens material*
- A reaction to lens material would typically manifest as **inflammatory response**, such as **uveitis**, **toxic anterior segment syndrome (TASS)**, or secondary **glaucoma**.
- Such reactions do not cause the mechanical oscillating movement described as windshield wiper syndrome.
- Modern **biocompatible IOLs** (acrylic, silicone) have significantly reduced the incidence of material-related reactions.
Lens Subluxation and Dislocation Indian Medical PG Question 10: A 10-year-old girl presents with severe joint laxity, scoliosis, and a history of easy bruising. Which of the following conditions is most likely?
- A. Ehlers-Danlos syndrome (Correct Answer)
- B. Marfan's syndrome
- C. Rheumatoid arthritis
- D. Osteogenesis imperfecta
Lens Subluxation and Dislocation Explanation: ***Ehlers-Danlos syndrome***
- This syndrome is characterized by defects in **collagen synthesis** and structure, leading to **joint hypermobility** (laxity) [1], skin hyperextensibility, and fragility, which explains the easy bruising [1].
- **Scoliosis** is a common musculoskeletal manifestation due to weakened connective tissue support [1].
*Marfan's syndrome*
- While Marfan's syndrome also presents with **joint laxity** and **scoliosis**, its defining features include distinct skeletal abnormalities (e.g., **arachnodactyly**, sternal deformities) and **cardiovascular abnormalities** (e.g., aortic root dilatation), which are not mentioned here.
- **Easy bruising** is not a prominent feature of Marfan's syndrome.
*Rheumatoid arthritis*
- This is an **autoimmune inflammatory arthritis** primarily affecting synovial joints, causing pain, swelling, and stiffness, often symmetrically.
- It does not typically present with severe **joint laxity** throughout the body, **scoliosis**, or **easy bruising** as primary features in a 10-year-old.
*Osteogenesis imperfecta*
- This condition is characterized by **brittle bones** due to defective collagen, leading to recurrent **fractures** with minimal trauma.
- While patients can have some **joint laxity** and **scoliosis**, the most prominent symptom is bone fragility, often accompanied by **blue sclerae**, which is not mentioned, and easy bruising is less indicative than in EDS.
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