Anatomy
1 questionsUnilateral lacrimal gland destruction may be caused by?
NEET-PG 2012 - Anatomy NEET-PG Practice Questions and MCQs
Question 661: Unilateral lacrimal gland destruction may be caused by?
- A. Fracture of roof of orbit (Correct Answer)
- B. Inferior orbital fissure fracture
- C. Fracture of lateral wall
- D. Fracture of sphenoid
Explanation: ***Fracture of roof of orbit*** - The **lacrimal gland** is situated in the **lacrimal fossa** on the anterior-lateral part of the **orbital roof**. A fracture in this specific area can directly damage the gland. - Trauma to the **orbital roof** can lead to laceration, avulsion, or compression of the lacrimal gland, resulting in its destruction and impairing tear production. *Inferior orbital fissure fracture* - The **inferior orbital fissure** transmits nerves and vessels to the orbit but is located inferior to the lacrimal gland, making direct injury unlikely. - Fractures here are more associated with **infraorbital nerve damage** or disruption of orbital contents into the maxillary sinus, not lacrimal gland destruction. *Fracture of lateral wall* - The **lateral wall of the orbit** forms the outer boundary and protects structures deeper within the orbit, but the lacrimal gland is situated superiorly and anteriorly. - While significant trauma to the lateral wall can impact orbital contents, it is less likely to directly cause unilateral lacrimal gland destruction compared to a direct roof fracture. *Fracture of sphenoid* - Fractures of the **sphenoid bone** are typically more posterior and central, affecting structures like the **optic canal** or **cavernous sinus**. - While it can indirectly affect orbital function, it is not a direct cause of isolated lacrimal gland destruction due to its anatomical location.
Internal Medicine
1 questionsWhich of the following is NOT typically seen in 3rd nerve palsy?
NEET-PG 2012 - Internal Medicine NEET-PG Practice Questions and MCQs
Question 661: Which of the following is NOT typically seen in 3rd nerve palsy?
- A. Mydriasis
- B. Ptosis
- C. Loss of abduction (Correct Answer)
- D. Loss of light reflex
Explanation: ***Loss of abduction*** - The **oculomotor nerve (CN III)** controls adduction, elevation, and depression of the eye, but **not abduction**. [2] - **Abduction** is primarily controlled by the **abducens nerve (CN VI)**, so its loss would indicate a CN VI palsy. *Mydriasis* - The **oculomotor nerve (CN III)** innervates the **parasympathetic fibers** to the pupillary constrictor muscles. [3] - Palsy of these fibers leads to unopposed action of the sympathetic dilator muscles, causing **mydriasis (pupil dilation)**. [4] *Ptosis* - The **oculomotor nerve (CN III)** innervates the **levator palpebrae superioris muscle**, which lifts the eyelid. - Dysfunction of this nerve leads to **ptosis (drooping of the eyelid)**. [1] *Loss of light reflex* - The **efferent pathway** for the **pupillary light reflex** travels via the **oculomotor nerve (CN III)** to constrict the pupil. [3] - A 3rd nerve palsy, particularly affecting the parasympathetic fibers, **impairs pupillary constriction**, resulting in a loss of the direct and consensual light reflex in the affected eye. [4]
Ophthalmology
8 questionsWhat does extraretinal fibrovascular proliferation at the ridge indicate?
In which condition is the swinging light test positive?
Most common malignant tumour of eyelid is ?
Bilateral ptosis is seen in all except which of the following?
Which of the following statements about corneal dystrophy is true?
What is the primary complication associated with Eale's disease?
Which muscle is the earliest to be involved in thyroid ophthalmopathy?
What is the treatment of choice for amblyopia?
NEET-PG 2012 - Ophthalmology NEET-PG Practice Questions and MCQs
Question 661: What does extraretinal fibrovascular proliferation at the ridge indicate?
- A. Normal retina
- B. Stage II Retinopathy of Prematurity
- C. Stage III Retinopathy of Prematurity (Correct Answer)
- D. Stage I Retinopathy of Prematurity
Explanation: ***Stage III Retinopathy of Prematurity*** - Extraretinal fibrovascular proliferation at the ridge is the defining characteristic of **Stage III Retinopathy of Prematurity (ROP)**. - This stage signifies significant **neovascularization** extending into the vitreous, increasing the risk of **retinal detachment**. *Normal retina* - A normal retina does not exhibit **fibrovascular proliferation** or a distinct ridge, as its vascularization is fully developed and confined to the retinal plane. - Absence of any abnormal vascular growth or demarcation line indicates a healthy, mature retinal structure. *Stage II Retinopathy of Prematurity* - Stage II ROP is characterized by a **ridge** that is elevated and appears three-dimensional, but it **lacks extraretinal fibrovascular proliferation**. - This stage represents progression from Stage I, where the demarcation line becomes a prominent ridge, but without new vessel formation outside the retina. *Stage I Retinopathy of Prematurity* - Stage I ROP is characterized by a thin, flat **demarcation line** distinguishing vascularized from avascular retina, without any significant elevation or fibrovascular proliferation. - This initial stage indicates an arrested phase of retinal vascular development, but without the more severe signs of neovascularization.
Question 662: In which condition is the swinging light test positive?
- A. Conjunctivitis
- B. Glaucoma
- C. Keratoconus
- D. Optic neuritis (Correct Answer)
Explanation: ***Optic neuritis*** - The swinging light test (also known as the **Marcus Gunn pupil** or relative afferent pupillary defect, RAPD) is positive when there is a significant **asymmetry in the afferent visual pathway** between the two eyes. - In optic neuritis, the **optic nerve** is inflamed and demyelinated, impairing the transmission of light signals to the brain, which leads to a paradoxical pupillary dilation when the light is swung from the unaffected to the affected eye. *Conjunctivitis* - This is an **inflammation of the conjunctiva**, the membrane lining the eyelid and sclera, which primarily affects the ocular surface. - It does not involve the optic nerve or afferent pupillary pathways, so the swinging light test would be **negative**. *Glaucoma* - Glaucoma is a condition characterized by **progressive optic nerve damage**, often associated with elevated intraocular pressure, leading to peripheral vision loss. - While it causes optic neuropathy, a positive swinging light test is typically seen only in **severe, asymmetric cases** and is not its primary diagnostic feature. *Keratoconus* - This is a non-inflammatory eye condition in which the normally round dome-shaped cornea **thins and bulges outward into a cone-like shape**. - It affects the **cornea's shape and vision quality**, but not the optic nerve or the afferent pupillary reflex pathway, thus the swinging light test would be negative.
Question 663: Most common malignant tumour of eyelid is ?
- A. Basal cell carcinoma (Correct Answer)
- B. Malignant melanoma
- C. Squamous cell carcinoma
- D. Sebaceous gland carcinoma
Explanation: ***Basal cell carcinoma*** - **Basal cell carcinoma (BCC)** accounts for approximately 85-95% of all eyelid malignancies, making it the most common type. - It often presents as a **pearly nodule** with telangiectatic vessels, frequently affecting the lower eyelid. *Squamous cell carcinoma* - **Squamous cell carcinoma (SCC)** is the second most common eyelid malignancy, but it is significantly less frequent (5-10%) than BCC. - SCC has a **higher metastatic potential** compared to BCC. *Malignant melanoma* - **Malignant melanoma** is a rare but highly aggressive eyelid tumor, accounting for less than 1% of all eyelid malignancies. - It is characterized by its **pigmented appearance** and rapid growth pattern. *Sebaceous gland carcinoma* - **Sebaceous gland carcinoma** is a relatively uncommon, but aggressive, tumor of the eyelid, comprising about 1-5% of cases. - It often mimics benign lesions like a **chalazion** or chronic blepharitis, leading to delayed diagnosis.
Question 664: Bilateral ptosis is seen in all except which of the following?
- A. Trauma
- B. Hyperthyroidism (Graves' disease) (Correct Answer)
- C. Congenital
- D. Myotonic dystrophy
Explanation: ***Hyperthyroidism (Graves' disease)*** - **Hyperthyroidism** causes eyelid retraction, leading to a **stare** or **lid lag**, rather than **ptosis**. - **Graves' ophthalmopathy** can cause proptosis (bulging eyes) and conjunctival injection, but does not typically manifest as ptosis. *Congenital* - **Congenital ptosis** is often present at birth due to improper development of the **levator palpebrae superioris muscle**. - It can be **bilateral** and is usually isolated, without other systemic symptoms. *Trauma* - **Traumatic ptosis** can occur if the **levator muscle**, **aponeurosis**, or **third cranial nerve** is damaged. - This can be **bilateral** depending on the nature and extent of the head trauma. *Myotonic dystrophy* - **Myotonic dystrophy** is a **hereditary muscle disorder** characterized by progressive muscle weakness. - **Bilateral ptosis** is a very common early sign of **myotonic dystrophy**, often accompanied by **facial weakness** and **myotonia**.
Question 665: Which of the following statements about corneal dystrophy is true?
- A. It involves neovascularization.
- B. It is caused by inflammation.
- C. It is usually unilateral.
- D. It is typically bilateral. (Correct Answer)
Explanation: ***It is typically bilateral.*** - **Corneal dystrophies** are inherited genetic disorders that usually affect both eyes symmetrically. - This bilateral presentation is a key characteristic distinguishing them from other corneal conditions. *It is caused by inflammation.* - **Corneal dystrophies** are primarily genetic and degenerative, not inflammatory. - While inflammation can cause corneal damage (e.g., keratitis), it is not the underlying cause of dystrophy. *It involves neovascularization.* - **Neovascularization** (growth of new blood vessels) is typically a response to chronic inflammation, hypoxia, or infection in the cornea. - It is generally not a feature of primary corneal dystrophies, which are characterized by abnormal deposits or structural changes within the corneal layers. *It is usually unilateral.* - As inherited genetic conditions, **corneal dystrophies** almost always affect both eyes. - Unilateral involvement would suggest a different etiology, such as trauma, infection, or a localized acquired condition.
Question 666: What is the primary complication associated with Eale's disease?
- A. Retinal hemorrhage
- B. Vitreous hemorrhage (Correct Answer)
- C. Conjunctival hemorrhage
- D. Choroidal hemorrhage
Explanation: ***Vitreous hemorrhage*** - **Vitreous hemorrhage** is a common and often visually debilitating complication of Eale's disease, resulting from the rupture of fragile new vessels. - The proliferative stage of Eale's disease involves the development of **neovascularization** on the retina, which can bleed into the vitreous humor. *Retinal hemorrhage* - While **retinal hemorrhages** can occur in Eale's disease, they are often precursors to or components of vitreous hemorrhage, not the primary, most significant complication. - Retinal hemorrhages alone may cause less severe vision loss compared to the extensive obscuration by vitreous bleeding. *Conjunctival hemorrhage* - **Conjunctival hemorrhage** involves bleeding in the superficial layers of the eye and is not typically associated with the underlying vasculitis of Eale's disease. - This is a benign condition and not a primary complication of a retinal vascular disorder. *Choroidal hemorrhage* - **Choroidal hemorrhage** occurs beneath the retina and is usually associated with trauma, surgery, or degenerative conditions like age-related macular degeneration, not Eale's disease. - Eale's disease primarily affects the **retinal vasculature**, leading to bleeding internally into the vitreous.
Question 667: Which muscle is the earliest to be involved in thyroid ophthalmopathy?
- A. Medial Rectus (MR)
- B. Inferior Rectus (IR) (Correct Answer)
- C. Superior Rectus (SR)
- D. Lateral Rectus (LR)
Explanation: ***Inferior Rectus (IR)*** - The **inferior rectus muscle** is most commonly and earliest affected in **thyroid ophthalmopathy** due to its anatomical location and muscle fiber type, making it highly susceptible to inflammation and edema. - Involvement of the inferior rectus leads to restricted **upward gaze** and **diplopia**, which are characteristic early symptoms of thyroid eye disease. *Medial Rectus (MR)* - While the **medial rectus** is often involved in thyroid ophthalmopathy, it is typically affected *after* the inferior rectus. - Dysfunction of the medial rectus manifests as difficulty with **adduction** (moving the eye inwards). *Superior Rectus (SR)* - The **superior rectus** is less frequently and usually later involved compared to the inferior and medial rectus muscles. - Its involvement typically causes restricted **downward gaze**. *Lateral Rectus (LR)* - The **lateral rectus** muscle is the *least common* ocular muscle to be affected in thyroid ophthalmopathy. - When affected, it primarily causes difficulty with **abduction** (moving the eye outwards).
Question 668: What is the treatment of choice for amblyopia?
- A. Corrective spectacles
- B. Surgical intervention
- C. Occlusion therapy (Correct Answer)
- D. Convergent exercises for vision therapy
Explanation: ***Occlusion therapy*** - **Occlusion therapy** involves patching the stronger eye to force the weaker, amblyopic eye to work harder, thereby strengthening its neural connections. - This treatment is most effective when initiated during the **critical period of visual development** in childhood. *Corrective spectacles* - While essential for addressing **refractive errors** that may contribute to amblyopia, spectacles alone are often insufficient to resolve the amblyopia. - Spectacles primarily optimize the image quality on the retina, but don't directly address the **cortical suppression** of the amblyopic eye. *Surgical intervention* - **Surgical intervention** is typically reserved for correcting structural issues like **strabismus** (misalignment of the eyes) that contribute to amblyopia. - Surgery for strabismus aims to align the eyes, which can then be followed by occlusion therapy or other treatments to address the functional amblyopia. *Convergent exercises for vision therapy* - **Vision therapy exercises**, including convergent exercises, may be used as an adjunct to occlusion therapy or in cases of **convergence insufficiency**. - However, they are not the primary or solitary treatment of choice for amblyopia, which requires direct stimulation of the amblyopic eye.