NEET-PG 2013 - Ophthalmology Practice Questions

Q: Which of the following is a specific sign of albinism?

Iris transillumination. ***Iris transillumination*** - This is a highly **specific sign** of albinism, resulting from the severe reduction or absence of pigment in the iris. - When light shines through the pupil, it passes through the unpigmented iris, creating a visible red reflex, indicating the lack of pigment that normally blocks the light. *Sensitivity to light (photophobia)* - While common in albinism due to the lack of pigment in the iris and retina allowing more light to enter the eye, **photophobia is not specific** to albinism. - It can be a symptom of various other ocular conditions like uveitis, corneal abrasions, or migraines. *Involuntary eye movements (nystagmus)* - **Nystagmus is frequently associated with albinism** due to foveal hypoplasia and impaired visual development but is **not specific**. - It can also be caused by neurological disorders, inner ear problems, or other ocular conditions. *Decreased visual acuity* - **Reduced vision is a characteristic feature of albinism** resulting from foveal hypoplasia and abnormal optic nerve pathways, but it is **not specific** to the condition. - Numerous eye conditions, such as refractive errors, cataracts, and retinal diseases, can lead to decreased visual acuity.

Q: Forced duction test is to find out?

Mechanical restriction of eye movement. ***Mechanical restriction of eye movement*** - The forced duction test is specifically designed to **detect mechanical restriction** that prevents free passive movement of the globe. - Performed under **topical anesthesia**, the examiner grasps the eye at the limbus with forceps and attempts to passively rotate it in the direction of limited motility. - A **positive test** (resistance to passive movement) indicates mechanical restriction from causes like **thyroid-associated orbitopathy, orbital floor fracture, entrapment, or fibrosis**. - This is the **primary clinical indication** for performing the test - to differentiate restrictive from paretic causes of strabismus. *Ocular muscle palsy* - In muscle palsy (paretic strabismus), the forced duction test is **negative** - the eye moves freely with passive movement. - The test helps **differentiate paretic from restrictive causes** of limited motility, but the test itself detects restriction, not palsy. - Free passive movement confirms that the limitation is due to muscle weakness rather than mechanical factors. *Ocular muscle spasm* - Active muscle spasm would not be detected by this test because it is performed **under topical or general anesthesia**, which eliminates active muscle contraction. - The test assesses **passive mechanical restriction**, not active muscle activity or spasm. - Spasm would be a neurogenic rather than mechanical cause and would show free passive movement on testing. *Angle of deviation* - The forced duction test does not measure the **degree or angle of deviation** in strabismus. - Tests like the **prism cover test** or **Hirschberg test** are used to quantify deviation. - The forced duction test provides qualitative information about the cause of limitation, not quantitative measurement of misalignment.

Q: Normal level of visual acuity is attained at which age

6 years. ***6 years*** - **Normal adult visual acuity (20/20 or 6/6)** is typically achieved around the age of **6 years** as the visual system fully matures. - This age allows for the complete development of **foveal vision** and **binocular functions**. *6 months* - At 6 months of age, an infant's visual acuity is still developing and is typically around **20/200 to 20/400**. - While significant visual development occurs by this age, including **face recognition and tracking objects**, it is not yet at adult levels. *1 year* - By one year, visual acuity improves to approximately **20/50 to 20/100**. - Infants at this age are able to **distinguish fine details** and have improved **depth perception**, but full maturity is still some years away. *3 years* - At 3 years of age, visual acuity is generally around **20/30 to 20/40**. - Children at this stage are able to perform **visual tasks** like drawing and recognizing letters, but subtle refinements are still ongoing.

Q: Binocular single vision is tested by?

Synoptophore. ***Synoptophore*** - The **synoptophore** is an ophthalmic instrument used to diagnose and treat various binocular vision anomalies, including **strabismus** and suppression. - It allows for the precise measurement and assessment of the eyes' ability to **fuse images** from both eyes into a single perception, which is the essence of **binocular single vision**. *Amsler grid* - The **Amsler grid** is primarily used to detect central visual field defects, such as those caused by **macular degeneration** or other retinal pathologies. - It does not directly assess the brain's ability to fuse images from both eyes into a single vision. *Cardboard test* - The "cardboard test" is not a standard ophthalmic test for binocular single vision. - It may refer to various informal or rudimentary tests, but it lacks the precision and standardization required for accurate assessment of binocular functions. *Maddox rod* - The **Maddox rod** is used to detect and measure **heterophoria** (latent strabismus) or **heterotropia** (manifest strabismus). - It dissociates the images seen by each eye, preventing fusion and revealing the deviation of the eyes, rather than directly testing the ability to achieve binocular single vision.

Q: Yoke muscle for the right superior rectus is:

Left Inferior Oblique. ***Left Inferior Oblique*** - Yoke muscles are pairs of synergistic muscles, one in each eye, that act together to produce conjugate eye movements in the same direction of gaze. - The **right superior rectus** and **left inferior oblique** are yoke muscles that work together during **upward and rightward gaze** (dextro-elevation) [1]. - Right SR elevates the **adducted** right eye, while left IO elevates the **abducted** left eye, producing coordinated upward-right movement [1]. - This follows **Hering's Law of Equal Innervation**, where yoke muscles receive equal and simultaneous innervation. *Left Superior rectus* - The left superior rectus is the **contralateral homologous muscle**, not a yoke muscle for the right superior rectus. - Both superior recti work together for **upward gaze in primary position**, but they are versional muscles, not yoke pairs. - Yoke muscles produce conjugate movements in oblique directions, not straight up. *Left Inferior rectus* - The left inferior rectus depresses the left eye and is an antagonist to elevation. - It would pair with the **right superior oblique** for downward-left gaze (levo-depression), not with the right superior rectus. *Left Lateral Rectus* - The left lateral rectus is responsible for **abduction** of the left eye (leftward gaze). - Its yoke muscle is the **right medial rectus** for leftward horizontal gaze (levoversion), not for upward-right gaze.

Q: In which condition is a positive forced duction test observed?

Mechanical restriction of ocular movement. ***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).

Q: What is the drug of choice for treating intermediate uveitis?

Systemic steroids. ***Systemic steroids*** - **Systemic steroids** are the **drug of choice** for treating intermediate uveitis, especially when inflammation is significant or vision is threatened. - They effectively suppress the expansive **intraocular inflammation** typical of intermediate uveitis, which often involves the **vitreous** and **peripheral retina**. *Atropine* - **Atropine** is a **cycloplegic agent** primarily used to relieve ciliary spasm and prevent synechiae formation in anterior uveitis. - It does not address the underlying **inflammation** of intermediate uveitis, which is located more posteriorly. *Antibiotics* - **Antibiotics** are used to treat bacterial infections and are not indicated for **intermediate uveitis**, which is typically an **inflammatory** or **autoimmune disorder**. - They would be appropriate only if the uveitis were secondary to an **infectious cause**, which is not the primary characteristic of intermediate uveitis. *Topical steroids* - **Topical steroids** are effective for **anterior uveitis** but often fail to reach sufficient concentrations in the **vitreous** and **peripheral retina** to control the inflammation of intermediate uveitis. - **Intermediate uveitis** primarily affects the ciliary body, vitreous, and peripheral retina, requiring **systemic agents** for adequate therapeutic effect.

Q: Reis-Buckler dystrophy affects which layer of the cornea?

Bowman's membrane. ***Bowman's membrane*** - **Reis-Buckler dystrophy** is a type of corneal dystrophy specifically characterized by the progressive destruction and irregular regeneration of **Bowman's membrane** and the superficial stroma. - This leads to the formation of an abnormal fibrous layer that causes recurrent corneal erosions and significant visual impairment due to corneal opacification. *Epithelium* - While patients often experience recurrent **corneal erosions** involving the epithelium, the primary pathology in Reis-Buckler dystrophy affects the underlying Bowman's membrane. - The epithelial damage is secondary to the irregular surface created by the diseased Bowman's layer. *Stroma* - The **stroma** can be secondarily affected with superficial scarring and opacification in Reis-Buckler dystrophy, but the initial and primary site of pathology is Bowman's membrane. - Other dystrophies, such as macular or granular dystrophies, primarily involve the corneal stroma. *Endothelium* - The **endothelium** is not directly affected in Reis-Buckler dystrophy. - Endothelial dystrophies, such as Fuchs' endothelial dystrophy, involve the innermost layer of the cornea and lead to corneal edema.

Q: Scissor reflex is seen in ?

Keratoconus. ***Keratoconus*** - The **scissor reflex**, or **scissoring reflex**, is a characteristic finding during **retinoscopy** in patients with **keratoconus**. - It is caused by the irregular and variable refractive power across the cornea, leading to a distorted red reflex that appears to split into two bands moving in opposite directions. *Open angle glaucoma* - **Open-angle glaucoma** is characterized by progressive damage to the **optic nerve** and visual field loss, typically with a normal open anterior chamber angle. - It does not involve abnormalities in corneal shape or light refraction that would produce a scissor reflex during retinoscopy. *Phlyctenular conjunctivitis* - **Phlyctenular conjunctivitis** is an inflammatory condition characterized by small nodular lesions (phlyctenules) on the conjunctiva or cornea, often associated with a hypersensitivity reaction to microbial antigens. - This condition primarily affects the surface of the eye and does not cause the corneal ectasia or irregular astigmatism seen in keratoconus. *Interstitial keratitis* - **Interstitial keratitis** is an inflammation of the corneal stroma without significant involvement of the epithelium or endothelium, often associated with systemic infections like syphilis or Lyme disease. - While it can cause corneal opacification and vision loss, it typically does not lead to the conical shape or irregular astigmatism characteristic of keratoconus, which produces the scissor reflex.

Q: In photophthalmia, which part of the eye is primarily affected?

Cornea. ***Cornea*** - **Photophthalmia** (also known as **snow blindness** or **arc eye**) is caused by overexposure to **ultraviolet (UV) light**, which primarily damages the **corneal epithelium**. - This damage leads to **superficial punctate keratitis**, characterized by pain, foreign body sensation, photophobia, and blurred vision. - Symptoms typically appear **6-12 hours after exposure** and resolve within **24-48 hours** with supportive care. *Retina* - The **retina** can be damaged by certain types of light (e.g., solar retinopathy from looking at the sun), but **UV light** in photophthalmia is largely absorbed by the anterior structures of the eye, particularly the cornea. - Retinal damage would typically present with **central visual loss** or **scotomas**, differing from the acute pain and photophobia of photophthalmia. *Optic nerve* - The **optic nerve** transmits visual information from the retina to the brain and is generally not directly affected by **UV light exposure** causing photophthalmia. - Optic nerve issues would manifest as severe **vision loss**, **pupillary abnormalities**, or **pain with eye movement**, which are not typical for photophthalmia. *Lens* - While chronic **UV exposure** can contribute to **cataract formation** in the lens over time, this is a long-term effect, not the acute primary damage seen in photophthalmia. - The acute presentation of photophthalmia with severe pain, photophobia, and foreign body sensation is characteristic of **corneal epithelial damage**, not lens involvement.

Question 1

Which of the following is a specific sign of albinism?

Accepted Answer

Iris transillumination

Answer

Sensitivity to light (photophobia)

Answer

Involuntary eye movements (nystagmus)

Answer

Decreased visual acuity

Question 2

Forced duction test is to find out?

Accepted Answer

Mechanical restriction of eye movement

Answer

Ocular muscle palsy

Answer

Ocular muscle spasm

Answer

Angle of deviation

Question 3

Normal level of visual acuity is attained at which age

Accepted Answer

6 years

Answer

6 months

Answer

1 year

Answer

3 years

Question 4

Binocular single vision is tested by?

Accepted Answer

Synoptophore

Answer

Amsler grid

Answer

Cardboard test

Answer

Maddox rod

Question 5

Yoke muscle for the right superior rectus is:

Accepted Answer

Left Inferior Oblique

Answer

Left Lateral Rectus

Answer

Left Superior rectus

Answer

Left Inferior rectus

Question 6

In which condition is a positive forced duction test observed?

Accepted Answer

Mechanical restriction of ocular movement

Answer

Non-concomitant strabismus

Answer

No condition

Answer

Extraocular muscle paralysis

Question 7

What is the drug of choice for treating intermediate uveitis?

Accepted Answer

Systemic steroids

Answer

Atropine

Answer

Antibiotics

Answer

Topical steroids

Question 8

Reis-Buckler dystrophy affects which layer of the cornea?

Accepted Answer

Bowman's membrane

Answer

Stroma

Answer

Endothelium

Answer

Epithelium

Question 9

Scissor reflex is seen in ?

Accepted Answer

Keratoconus

Answer

Open angle glaucoma

Answer

Phlyctenular conjunctivitis

Answer

Interstitial keratitis

Question 10

In photophthalmia, which part of the eye is primarily affected?

Accepted Answer

Cornea

Answer

Lens

Answer

Retina

Answer

Optic nerve

NEET-PG 2013 — Ophthalmology