NEET-PG 2015 Practice Questions

Q: How can homicidal gunshot wounds be differentiated from suicidal gunshot wounds?

Presence of signs of struggle. ***Correct Option: Presence of signs of struggle*** - **Signs of struggle** (defensive wounds, abrasions, bruising, torn clothing, disturbed surroundings) are the **most reliable indicator of homicidal gunshot wounds** - **Forensic significance**: Defense wounds on hands/forearms, struggle marks, and signs of restraint strongly suggest the victim resisted an attacker - **Absent in suicide**: Suicidal acts occur without external confrontation, so defensive injuries and struggle signs are typically absent - This is the **primary forensic differentiator** between homicide and suicide in gunshot cases *Incorrect: Presence of multiple gunshot wounds* - While **more common in homicide**, multiple gunshot wounds **CAN occur in suicide** (documented as "hesitation wounds" or multiple attempts with non-fatal first shots) - **Not a reliable sole differentiator**: Cases of suicidal individuals firing multiple shots are well-documented in forensic literature, especially with small caliber weapons or when vital organs are missed - Other factors (wound location, distance, angle) are needed for complete assessment *Incorrect: Presence of gunpowder on hands* - **Gunshot residue (GSR) on victim's hands** actually **indicates suicide** rather than homicide, as it suggests the victim held and fired the weapon - In **homicide**, GSR is typically **absent** from the victim's hands (unless they struggled for the weapon) - This differentiates suicide FROM homicide, but the question asks how to identify homicide *Incorrect: None of the above* - This is incorrect because **specific forensic indicators exist** to differentiate homicidal from suicidal gunshot wounds - Signs of struggle provide the most reliable differentiation

Q: Which is the most powerful refractive surface of the eye?

Cornea. ***Cornea*** - The **cornea** is the eye's outermost, transparent layer, responsible for approximately **two-thirds of the total refractive power** of the eye due to its highly curved anterior surface and the significant change in refractive index from air to corneal tissue. - Its fixed curvature and consistent refractive index make it the primary and most powerful component in bending light rays to focus them on the retina. *Conjunctiva* - The **conjunctiva** is a thin, translucent mucous membrane that lines the inner surface of the eyelids and covers the anterior sclera (white part of the eye). - Its primary function is protection and lubrication, producing mucus and tears, but it plays **no significant role in light refraction**. *Vitreous* - The **vitreous humor** is a transparent, gel-like substance that fills the space between the lens and the retina, maintaining the eye's shape. - It has a refractive index very similar to water (approximately 1.334) and contributes **minimally to the eye's total refractive power** because light has already been significantly refracted by the cornea and lens before reaching it. *Lens* - The **lens** is a transparent, biconvex structure located behind the iris, providing the remaining **one-third of the eye's refractive power**. - While crucial for **accommodation** (changing focal length to see objects at different distances), its refractive power is less than the cornea's, and its ability to change shape is what makes it unique, not its absolute power.

Q: Strabismic amblyopia is more common in patients with:

Constant strabismus. **Constant Strabismus** - In **constant strabismus**, one eye is always deviated, leading to **continuous suppression** of the image from the deviated eye by the brain. - This consistent suppression prevents proper visual development in the deviated eye, resulting in **amblyopia**. *Alternating strabismus* - In **alternating strabismus**, the deviation switches between the two eyes, allowing each eye to take turns fixing. - This alternation helps maintain relatively good visual acuity in both eyes, making **amblyopia less common** or severe. *Latent strabismus* - **Latent strabismus** (phoria) is a deviation that is only present when binocular fusion is disrupted (e.g., when one eye is covered). - Since fusion is typically maintained in daily vision, there is **no constant suppression** of one eye, and amblyopia is rare. *Intermittent strabismus* - **Intermittent strabismus** involves periods of deviation alternating with periods of straight eye alignment, often varying with fatigue or visual tasks. - While it can lead to amblyopia, it is **less common and severe** than with constant strabismus because there are periods when the visual input from both eyes is utilized.

Q: What term describes a condition where the axial length of the eye does not match its refractive power?

Axial Ametropia. ***Axial Ametropia*** - This term precisely describes a refractive error where the **axial length** of the eye is either too long or too short relative to its **optical power**, leading to images focusing in front of or behind the retina. - Examples include **myopia** (eye too long) and **hyperopia** (eye too short), which are fundamentally caused by a mismatch in axial length. *Anisokonia* - This condition refers to a significant difference in the **perceived size of images** between the two eyes, often due to unequal refractive errors between the eyes. - It does not directly describe the mismatch between axial length and refractive power itself, but rather a perceptual consequence that can result from asymmetric refractive errors. *Curvature ametropia* - This type of ametropia occurs when the **curvature** of the cornea or lens is abnormal, causing light rays to converge incorrectly. - While it's a form of refractive error, it specifically relates to the curvature of refractive surfaces, not the overall **axial length** of the eyeball. *Emmetropia* - This is the state of having **perfect vision**, where the refractive power of the eye correctly matches its axial length, allowing light to focus precisely on the retina without accommodation. - It describes the absence of refractive error, which is the opposite of the condition described in the question.

Q: In a case of myopia, LASIK can correct up to how many diopters?

-12D. ***-12D*** - LASIK can effectively correct myopia up to approximately **-12 diopters** in suitable candidates, though this can vary slightly based on individual corneal thickness and health. - The excimer laser reshapes the **cornea** to reduce its curvature, thereby decreasing the focusing power of the eye and correcting the myopic error. *-20D* - While some highly myopic individuals might desire such a correction, LASIK is generally not recommended or effective for myopia higher than **-12 to -14 diopters** due to limitations in corneal tissue removal and potential for complications. - Correcting very high myopia with LASIK would require removing too much corneal tissue, potentially leading to **corneal instability** or vision-threatening complications like **ectasia**. *-6D* - This is a common and highly successful range for LASIK correction, but it represents only a **moderate level of myopia** and not the maximum correctable range. - Patients with myopia of -6D typically achieve excellent visual outcomes with very low complication rates after LASIK. *-4D* - This is a relatively low level of myopia, and LASIK is very effective for this amount of correction, but it is far from the **upper limit** of what LASIK can achieve. - This level of correction requires minimal corneal reshaping and typically results in a very high success rate and predictable outcomes.

Q: Which of the following statements about pterygium is false?

Arise from any part of conjunctiva. ***Arise from any part of conjunctiva*** **(FALSE - Correct Answer)** - This statement is **FALSE** and thus the correct answer. - Pterygium characteristically arises from the **nasal (interpalpebral) bulbar conjunctiva** in 90-95% of cases. - It does NOT arise from "any part" - it has a specific predilection for the medial (nasal) limbus in the palpebral fissure zone. - Temporal pterygium is much less common (~10% of cases). *Can cause astigmatism* **(TRUE)** - This statement is TRUE. - As a pterygium grows across the cornea, it can induce **corneal astigmatism** by altering the curvature of the cornea. - This irregular corneal surface can blur vision, especially as the pterygium progresses towards the central visual axis. *Surgery is treatment of choice* **(TRUE)** - This statement is TRUE. - **Surgical excision** is the primary treatment for pterygium when it is symptomatic, threatens vision, or causes significant cosmetic concerns. - Indications for surgery include: growth towards the visual axis, inducing high astigmatism, significant discomfort, or cosmetic desire. - Adjunctive measures (mitomycin C, conjunctival autograft) help reduce recurrence. *UV exposure is risk factor* **(TRUE)** - This statement is TRUE. - **Ultraviolet (UV) radiation exposure** is a well-established and significant risk factor for the development and progression of pterygium. - This explains its higher prevalence in individuals living in sunny climates (between 37° N and 37° S latitude - "pterygium belt") and those with outdoor occupations.

Q: Silk retina is seen in ?

Retinal detachment. ***Retinal detachment*** - **"Silk retina" or "silky sheen"** is a classic ophthalmoscopic finding in retinal detachment, describing the **smooth, glistening appearance** of the detached sensory retina. - The detached retina appears **elevated, gray, and translucent** with characteristic folds or undulations, exhibiting a **satiny or silky luster** when examined. - Patients typically present with **photopsias (flashes of light)**, **floaters**, and progressive **visual field defect** described as a "curtain" or "shadow." - This is a true **ophthalmic emergency** requiring urgent surgical intervention. *Diabetic retinopathy* - Characterized by **microaneurysms, dot-blot hemorrhages, hard exudates**, and **cotton-wool spots** in non-proliferative stages. - Proliferative diabetic retinopathy shows **neovascularization** and vitreous hemorrhage. - Does not produce the "silk retina" appearance. *Macular degeneration* - Age-related macular degeneration presents with **drusen, pigmentary changes**, and in advanced stages, **geographic atrophy** or **choroidal neovascularization**. - May show a **"beaten-bronze" appearance** in certain macular dystrophies (Best's disease), but not "silk retina." - Central vision loss is the predominant symptom. *Hypertensive retinopathy* - Features include **generalized arteriolar narrowing, AV nicking, flame-shaped hemorrhages**, and **cotton-wool spots**. - In severe cases (Grade IV), **optic disc edema** and macular star exudates may occur. - Vascular changes dominate the clinical picture, not a silky retinal appearance.

Q: Pseudopapilledema with tigroid fundus appearance is seen in?

Myopia. ***Myopia*** - **Pseudopapilledema** with a **tigroid fundus** (tessellated or salt-and-pepper appearance) is characteristically observed in high myopia due to the oblique entry of the **optic nerve** into the globe and thinning of the choroid and retinal pigment epithelium. - The pseudopapilledema is caused by the crowding of axons and glial tissue within the optic disc, giving a raised appearance, and is distinct from true papilledema which involves **optic disc edema** due to increased **intracranial pressure**. - The tigroid fundus results from the visibility of underlying **choroidal vessels** through the attenuated retinal pigment epithelium in the stretched, elongated myopic eye. *Hypermetropia* - **Hypermetropia** (farsightedness) typically presents with a small, compact optic disc, but does not exhibit the specific findings of **pseudopapilledema** or tigroid fundus. - This condition is characterized by the eye being too short or the lens having insufficient power, causing light to focus behind the retina. *Astigmatism* - **Astigmatism** is characterized by an **irregularly shaped cornea** or lens, leading to blurred vision at all distances. - While it can cause some distortion, it is not associated with the specific optic disc appearance of **pseudopapilledema** or the fundus changes seen in high myopia. *Presbyopia* - **Presbyopia** is an age-related condition where the eye's natural lens loses its flexibility, making it difficult to focus on **near objects**. - It affects the **accommodative ability** of the eye and does not manifest with any characteristic changes in the optic disc morphology such as **pseudopapilledema** or retinal/choroidal changes.

Question 1

How can homicidal gunshot wounds be differentiated from suicidal gunshot wounds?

Accepted Answer

Presence of signs of struggle

Answer

Presence of multiple gunshot wounds

Answer

Presence of gunpowder on hands

Answer

None of the above

Question 2

Which is the most powerful refractive surface of the eye?

Accepted Answer

Cornea

Answer

Conjunctiva

Answer

Vitreous

Answer

Lens

Question 3

Strabismic amblyopia is more common in patients with:

Accepted Answer

Constant strabismus

Answer

Alternating strabismus

Answer

Latent strabismus

Answer

Intermittent strabismus

Question 4

Astigmatism is defined as?

Accepted Answer

Refractive error wherein refraction varies along different meridians

Answer

Refractive error due to long AP length of eyeball

Answer

Varying refractive error in both eyes

Answer

Varying shape perception by both eyes

Question 5

What is regular astigmatism?

Accepted Answer

Astigmatism where the principal meridians are at a 90-degree angle to each other

Answer

Astigmatism in which the principal meridians are parallel

Answer

Asymptomatic astigmatism

Answer

Astigmatism as a result of cataract surgery

Question 6

What term describes a condition where the axial length of the eye does not match its refractive power?

Accepted Answer

Axial Ametropia

Answer

Anisokonia

Answer

Emmetropia

Answer

Curvature ametropia

Question 7

In a case of myopia, LASIK can correct up to how many diopters?

Accepted Answer

-12D

Answer

-4D

Answer

-20D

Answer

-6D

Question 8

Which of the following statements about pterygium is false?

Accepted Answer

Arise from any part of conjunctiva

Answer

Can cause astigmatism

Answer

Surgery is treatment of choice

Answer

UV exposure is risk factor

Question 9

Silk retina is seen in ?

Accepted Answer

Retinal detachment

Answer

Diabetic retinopathy

Answer

Macular degeneration

Answer

Hypertensive retinopathy

Question 10

Pseudopapilledema with tigroid fundus appearance is seen in?

Accepted Answer

Myopia

Answer

Astigmatism

Answer

Presbyopia

Answer

Hypermetropia

NEET-PG 2015

Forensic Medicine

Ophthalmology