In which condition is a positive forced duction test observed?
The earliest change noticed in hypertensive retinopathy is:
Hordeolum internum is?
In congenital dacryocystitis, the blockage occurs at?
The best local anesthetic for prolonged ophthalmic surgery requiring extended post-operative analgesia is:
Fluorescein angiography is used to examine -
Most common type of scleritis is
Most common cause of ptosis in adults
All are ophthalmological emergencies except -
Surgery of choice in a patient with congenital ptosis with good levator action is:
NEET-PG 2013 - Ophthalmology NEET-PG Practice Questions and MCQs
Question 61: In which condition is a positive forced duction test observed?
- A. Mechanical restriction of ocular movement (Correct Answer)
- B. Non-concomitant strabismus
- C. No condition
- D. Extraocular muscle paralysis
Explanation: ***Mechanical restriction of ocular movement*** - A **positive forced duction test** indicates a physical impediment to eye movement, meaning the eye cannot be passively moved beyond a certain point. - This test is crucial for differentiating between **muscle restriction** (e.g., thyroid eye disease, orbital floor fracture with muscle entrapment, post-surgical adhesions) and muscle weakness or paralysis. - When the examiner attempts to passively rotate the globe, there is **resistance** indicating mechanical tethering or restriction of the extraocular muscles. *Non-concomitant strabismus* - This refers to a squint where the magnitude of deviation varies with the direction of gaze. - While it can be caused by muscle restriction, non-concomitant strabismus itself is a **type of ocular misalignment**, not the specific finding of a forced duction test. - The forced duction test helps determine the **cause** of non-concomitant strabismus (mechanical vs. paralytic). *No condition* - This option is incorrect because a positive forced duction test specifically indicates mechanical obstruction or restriction in eye movement. - A positive result always points to an underlying pathological condition affecting ocular motility, not a normal finding. *Extraocular muscle paralysis* - In cases of **muscle paralysis**, the eye cannot move actively in the direction of the paralyzed muscle's action. - However, the **forced duction test would be negative** as the globe can be passively moved in all directions because there is no mechanical restriction. - This differentiates paralytic strabismus (negative test) from restrictive strabismus (positive test).
Question 62: The earliest change noticed in hypertensive retinopathy is:
- A. Soft exudate
- B. Arteriolar spasm (Correct Answer)
- C. Venospasm
- D. Hard exudate
Explanation: ***Arteriolar spasm*** - **Arteriolar spasm** is the **earliest functional change** and is characterized by increased vascular tone in response to elevated blood pressure. - This spasm is a dynamic process and often leads to **narrowing of the retinal arterioles**, which can be observed during fundoscopic examination. *Soft exudate* - **Soft exudates**, also known as **cotton wool spots**, represent areas of **ischemic retinal nerve fiber layer** damage due to obstruction of precapillary arterioles. - These are typically seen in later stages of hypertensive retinopathy, indicating more significant vascular damage and ischemia. *Venospasm* - **Venospasm**, or narrowing of retinal veins, is **not a primary or early finding** in hypertensive retinopathy. - While venous changes like tortuosity can occur, arterial changes dominate the early pathogenesis. *Hard exudate* - **Hard exudates** are yellow-white deposits of **lipid and protein** that leak from damaged capillaries, often indicative of chronic retinal edema and incompetent blood-retinal barrier. - These usually appear in **more advanced stages** of hypertensive retinopathy and are not considered the earliest change.
Question 63: Hordeolum internum is?
- A. Chronic infection of Zeis gland
- B. Acute infection of Moll gland
- C. Acute infection of Zeis gland
- D. Acute infection of Meibomian gland (Correct Answer)
Explanation: ***Acute infection of Meibomian gland*** - A **hordeolum internum** is an acute, purulent infection of the **Meibomian glands**, which are sebaceous glands located within the tarsal plate of the eyelid. - The infection primarily manifests on the **inner surface of the eyelid** due to the gland's location, causing localized inflammation and pain. *Acute infection of Zeis gland* - An acute infection of a **Zeis gland** (a sebaceous gland connected to an eyelash follicle) is known as a **hordeolum externum**, or external stye. - Unlike a hordeolum internum, a **hordeolum externum** usually points externally at the lid margin. *Acute infection of Moll gland* - An acute infection of a **Moll gland** (apocrine sweat glands located near the lid margin) is also a type of **hordeolum externum**. - While it's an acute infection of an eyelid gland, it is not specifically referred to as a **hordeolum internum**. *Chronic infection of Zeis gland* - A chronic infection of a **Zeis gland** is not a typical designation for eyelid lesions; chronic inflammatory processes of sebaceous glands often lead to conditions like a **chalazion**, though chalazia are more commonly associated with Meibomian glands. - This option incorrectly identifies the gland for a hordeolum internum and specifies **chronic infection**, whereas a hordeolum is inherently **acute**.
Question 64: In congenital dacryocystitis, the blockage occurs at?
- A. Nasolacrimal duct (Correct Answer)
- B. Punctum
- C. Lacrimal canaliculi
- D. Lacrimal sac
Explanation: ***Nasolacrimal duct*** - **Congenital dacryocystitis** is primarily caused by an obstruction in the **nasolacrimal duct**, specifically at the **valve of Hasner** at its distal end near the inferior meatus. - This blockage prevents the proper drainage of tears into the nasal cavity, leading to tear overflow (epiphora), mucoid discharge, and potential secondary infection. - Present in approximately **5-6% of newborns**, with most cases resolving spontaneously by 12 months of age. *Punctum* - Congenital **punctal agenesis** is rare and not the typical site of obstruction in congenital dacryocystitis. - The puncta are usually patent in this condition. *Lacrimal canaliculi* - Obstruction of the **lacrimal canaliculi** is uncommon in congenital cases. - Canalicular obstruction is more often acquired (trauma, infection, medications). *Lacrimal sac* - The **lacrimal sac** itself is not the site of primary obstruction in congenital dacryocystitis. - The sac may become distended due to downstream obstruction at the nasolacrimal duct.
Question 65: The best local anesthetic for prolonged ophthalmic surgery requiring extended post-operative analgesia is:
- A. Tetracaine
- B. Procaine
- C. Prilocaine
- D. Bupivacaine (Correct Answer)
Explanation: ***Bupivacaine*** - **Bupivacaine** is an amide-type local anesthetic known for its **long duration of action** due to its high protein binding and lipid solubility. - This property makes it ideal for procedures requiring **prolonged analgesia**, such as extended ophthalmic surgery and post-operative pain control. *Tetracaine* - **Tetracaine** is an ester-type local anesthetic primarily used for **topical anesthesia**, especially in ophthalmology. - While effective for surface anesthesia, its duration of action is relatively short, making it unsuitable for prolonged surgical procedures requiring sustained nerve block. *Procaine* - **Procaine** is an ester-type local anesthetic with a **short duration of action** and is generally associated with a higher incidence of allergic reactions. - It is rarely used today for major regional blocks due to its limited potency and short effect, unlike the requirement for prolonged ophthalmic surgery. *Prilocaine* - **Prilocaine** is an amide-type local anesthetic with an **intermediate duration of action**. - Its use is limited in some cases due to its potential to cause **methemoglobinemia** at higher doses, making it less suitable for applications requiring extensive or prolonged regional anesthesia compared to bupivacaine.
Question 66: Fluorescein angiography is used to examine -
- A. Ciliary vasculature
- B. Retinal vasculature (Correct Answer)
- C. Corneal vasculature
- D. Conjunctival vasculature
Explanation: ***Retinal vasculature*** - **Fluorescein angiography** involves injecting fluorescein dye into a vein and taking rapid photographs of the retina as the dye perfuses, allowing for detailed visualization of the **retinal blood vessels**. - This technique is crucial for diagnosing and monitoring conditions like **diabetic retinopathy**, **macular degeneration**, and **retinal vascular occlusions** by identifying leaks, non-perfusion areas, and abnormal vessel growth. *Ciliary vasculature* - The **ciliary body vasculature** is not directly visualized by standard fluorescein angiography as it is located anterior to the retina within the uveal tract. - While some dye may perfuse the ciliary body, the primary imaging target and diagnostic utility of fluorescein angiography are the **retinal and choroidal circulations**. *Corneal vasculature* - The normal **cornea is avascular**, meaning it does not contain blood vessels. - **Corneal neovascularization** (new vessel growth) can occur due to pathology, but fluorescein angiography is not the primary or most suitable technique for assessing corneal vessels, which are more readily visible with slit-lamp biomicroscopy. *Conjunctival vasculature* - The **conjunctiva** contains numerous small vessels, but these are superficial and can be directly observed with a slit lamp or even the naked eye. - Fluorescein angiography is an invasive procedure with a higher spatial resolution designed for deeper, more intricate vascular networks like those in the retina, making it overkill and inappropriate for routine assessment of the **conjunctival vasculature**.
Question 67: Most common type of scleritis is
- A. Diffuse anterior
- B. Nodular anterior
- C. Anterior (Correct Answer)
- D. Posterior
Explanation: ***Anterior*** - **Anterior scleritis** accounts for approximately **98%** of all scleritis cases, making it the most common type. - It involves inflammation of the sclera anterior to the **equator of the globe**, visible on external examination. - Anterior scleritis is further subdivided into **diffuse, nodular,** and **necrotizing** forms based on clinical presentation and severity. *Diffuse anterior* - **Diffuse anterior scleritis** is the most common subtype of anterior scleritis, characterized by widespread inflammation. - While common among anterior types, it represents a subset rather than the overall most common anatomical category. *Nodular anterior* - **Nodular anterior scleritis** presents with discrete nodules of inflamed scleral tissue. - It is less common than diffuse anterior scleritis but more common than necrotizing forms. *Posterior* - **Posterior scleritis** is rare, accounting for only about **2%** of all scleritis cases. - It involves inflammation posterior to the **equator of the globe** and can be difficult to diagnose due to its hidden location, often presenting with pain, proptosis, and vision loss.
Question 68: Most common cause of ptosis in adults
- A. Idiopathic
- B. Myasthenia gravis
- C. Aponeurotic (Correct Answer)
- D. Paralysis of 3rd nerve
Explanation: ***Aponeurotic*** - **Aponeurotic ptosis** is the most common cause of adult-onset ptosis, resulting from a dehiscence, disinsertion, or stretching of the **levator aponeurosis**. - It typically presents as a gradual onset of ptosis and often occurs bilaterally, though one eye may be more affected. *Idiopathic* - While many cases may initially be labeled idiopathic, a specific cause, such as **aponeurotic changes**, is often identified upon closer examination. - This term is a general descriptor and not a specific pathophysiological mechanism. *Myasthenia gravis* - **Myasthenia gravis** can cause fluctuating ptosis that worsens with fatigue, but it is not the most common cause overall. - It is an **autoimmune neuromuscular junction disorder** characterized by weakness in various skeletal muscles. *Paralysis of 3rd nerve* - **Third nerve palsy** causes ptosis along with other signs like an **out-and-down eye deviation** and a **dilated pupil** (if parasympathetic fibers are involved). - While it causes significant ptosis, it is less common than aponeurotic ptosis and presents with a distinct constellation of symptoms.
Question 69: All are ophthalmological emergencies except -
- A. Endophthalmitis
- B. CRVO (Correct Answer)
- C. Acute congestive glaucoma
- D. CRAO
Explanation: ***CRVO*** - Central Retinal Vein Occlusion (CRVO) is characterized by painless **vision loss** due to retinal hemorrhage and edema, but it is generally *not* considered an immediate, vision-threatening emergency in the same vein as the other options. - While it requires prompt evaluation and management to preserve vision, CRVO allows for a less urgent intervention compared to conditions that can lead to permanent vision loss within hours. *Endophthalmitis* - **Endophthalmitis** is a severe inflammation of the intraocular fluids and tissues, typically caused by infection, and can lead to rapid and irreversible vision loss if not treated urgently. - It presents with pain, redness, reduced vision, and hypopyon (pus in the anterior chamber), necessitating immediate antibiotic treatment and surgical intervention. *Acute congestive glaucoma* - **Acute congestive glaucoma** (acute angle-closure glaucoma) involves a sudden increase in intraocular pressure, causing severe pain, redness, corneal edema, and profound vision loss. - If left untreated, the high pressure can cause irreversible damage to the optic nerve within hours, making it a true ocular emergency. *CRAO* - **Central Retinal Artery Occlusion (CRAO)** is a sudden, painless loss of vision in one eye due to blockage of the central retinal artery, leading to retinal ischemia. - It is an ocular emergency because irreversible retinal damage and vision loss can occur within 90-120 minutes of the occlusion, requiring immediate intervention to restore blood flow.
Question 70: Surgery of choice in a patient with congenital ptosis with good levator action is:
- A. Fascia lata sling surgery
- B. Fasanella-Servat operation
- C. Müller's resection
- D. LPS resection (Correct Answer)
Explanation: ***LPS resection*** - **Levator palpebrae superioris (LPS) resection** is the surgery of choice for congenital ptosis with **good levator action** (typically defined as >8-10 mm of levator function). - This procedure directly shortens and strengthens the **levator muscle**, improving eyelid elevation. *Fascia lata sling surgery* - This procedure is indicated for patients with **poor or absent levator function** (typically <4 mm). - It involves suspending the eyelid to the **frontalis muscle** using a sling material, often **fascia lata**, to allow eyebrow elevation to lift the eyelid. *Fasanella-Servat operation* - This is a minimally invasive procedure used for **mild ptosis** with **excellent levator action** (>10 mm). - It involves resecting a small amount of **Müller's muscle**, **conjunctiva**, and occasionally the **tarsal plate**, but is less effective for moderate-to-severe ptosis. *Müller's resection* - **Müller's muscle resection** is generally reserved for **mild ptosis** (1-2 mm) that responds positively to the **phenylephrine test**. - It primarily addresses ptosis due to sympathetic denervation or mild aponeurotic disinsertion, not significant congenital ptosis with good levator function.