Dalrymple's sign of ocular Graves' disease refers to which of the following?
D Shaped pupil is seen in which condition?
In which of the following conditions does Berlin's edema occur?
All of the following are complications of traumatic hyphema except which of the following?
What is the most common eye lesion in HIV?
A patient sustained an eye injury leading to corneal opacification and complete vision loss in the affected eye. Following successful corneal grafting, the patient regained clear vision. According to injury severity classification, this injury would be categorized as:
Which optical instrument utilizes the principle of total internal reflection?
Which cells in the retina are primarily affected by methanol toxicity?
Which of the following methods is not used to measure refractive error?
NEET-PG 2015 - Ophthalmology NEET-PG Practice Questions and MCQs
Question 51: Dalrymple's sign of ocular Graves' disease refers to which of the following?
- A. Retraction of the upper lid (Correct Answer)
- B. Lid lag
- C. Proptosis
- D. Convergence insufficiency
Explanation: ***Retraction of the upper lid*** - **Dalrymple's sign** specifically refers to the **wide-eyed stare** seen in **Graves' ophthalmopathy** due to **retraction of the upper eyelid**. - This symptom is caused by sympathetic overactivity of the **levator palpebrae superioris muscle**. *Lid lag* - **Lid lag (Graefe's sign)** is a different ocular sign where the **upper eyelid lags behind the globe** on downward gaze. - While also seen in **Graves' disease**, it is distinct from constant upper lid retraction. *Proptosis* - **Proptosis**, or **exophthalmos**, is the **forward protrusion of the eyeball** from the orbit. - This is a common feature of **Graves' ophthalmopathy**, but it is not what Dalrymple's sign refers to. *Convergence insufficiency* - **Convergence insufficiency (Moebius sign)** refers to the **inability to maintain convergence** during near vision. - While this can occur in **thyroid eye disease**, it is not Dalrymple's sign.
Question 52: D Shaped pupil is seen in which condition?
- A. Anterior synechiae
- B. Anterior Uveitis
- C. Iridodialysis (Correct Answer)
- D. Iridodonesis
Explanation: ***Iridodialysis*** - **Iridodialysis** is a disinsertion or separation of the iris from its root at the ciliary body. - This separation creates a D-shaped or keyhole pupil, as the detached portion of the iris no longer contributes to the circular pupillary margin. *Anterior Uveitis* - **Anterior uveitis** is inflammation of the iris and ciliary body, primarily causing miosis (constricted pupil), not a D-shaped pupil. - It can lead to posterior synechiae, resulting in an irregular, but not typically D-shaped, pupil. *Anterior synechiae* - **Anterior synechiae** involve adhesions between the iris and the corneal endothelium or trabecular meshwork. - While they can cause an irregular pupil shape, they typically pull the iris towards the cornea rather than creating a D-shape from iris root disinsertion. *Iridodonesis* - **Iridodonesis** refers to tremors or wobbling of the iris, often seen in cases of aphakia or subluxated lenses, due to lack of support. - It describes a movement disorder of the iris rather than an abnormal, fixed pupil shape like a D-shaped pupil.
Question 53: In which of the following conditions does Berlin's edema occur?
- A. Open angle glaucoma
- B. After cataract surgery
- C. After concussional trauma (Correct Answer)
- D. Diabetic retinopathy
Explanation: ***After concussional trauma*** - **Berlin's edema**, also known as **commotio retinae**, is a form of **retinal edema** that occurs following **blunt trauma** to the eye. - It results from the disruption of the **photoreceptor outer segments** and retinal pigment epithelium, leading to a **dull, gray-white appearance** of the retina. *Open angle glaucoma* - Characterized by **progressive optic nerve damage** and visual field loss, typically due to elevated intraocular pressure, without retinal edema. - The primary pathology involves the **trabecular meshwork**, not direct retinal swelling. *After cataract surgery* - A common complication is **cystoid macular edema** (Irvine-Gass syndrome), which affects the macula and can cause blurred vision. - This is distinct from Berlin's edema, as it is a **post-surgical inflammatory response**, not a direct traumatic injury. *Diabetic retinopathy* - Involves various retinal changes due to diabetes, such as **microaneurysms**, hemorrhages, and **macular edema** from leaky vessels. - It is a **metabolic and vascular disease**, not a direct consequence of acute ocular trauma.
Question 54: All of the following are complications of traumatic hyphema except which of the following?
- A. Pupillary Block
- B. Posterior synechiae
- C. Rebleeding
- D. Corneal Ulcer (Correct Answer)
Explanation: ***Corneal Ulcer*** - A **corneal ulcer** is typically caused by infection, trauma, or exposure keratitis and is not a direct complication of blood in the anterior chamber from a **traumatic hyphema**. - While prolonged elevation of **intraocular pressure** from hyphema could theoretically impair corneal health, a direct ulcer is not a typical or primary complication. *Rebleeding* - **Rebleeding** is a common and serious complication of hyphema, usually occurring 2-7 days after the initial injury. - It often results in a more significant bleed and carries a higher risk of complications such as **elevated intraocular pressure** and **blood staining of the cornea**. *Pupillary Block* - **Pupillary block** can occur if the amount of blood from the hyphema prevents the flow of aqueous humor from the posterior to the anterior chamber. - This blockage leads to a buildup of **aqueous humor** in the posterior chamber, causing the iris to bow forward and potentially precipitating **acute angle-closure glaucoma**. *Posterior synechiae* - **Posterior synechiae** can develop due to inflammation (uveitis) associated with the hyphema, where the iris adheres to the anterior lens capsule. - This complication can lead to **irregular pupil shape**, **pupillary block glaucoma**, or other visual disturbances.
Question 55: What is the most common eye lesion in HIV?
- A. Kaposi Sarcoma of Lid
- B. Cotton wool spots (Correct Answer)
- C. CMV Retinitis
- D. Choroiditis
Explanation: ***Cotton wool spots*** - These are the most common ocular manifestation in HIV-positive individuals, resulting from **ischemic retinal nerve fiber layer damage**. - While not vision-threatening themselves, their presence indicates **microvascular damage** and can be a sign of systemic disease progression. *Kaposi Sarcoma of Lid* - While Kaposi sarcoma can affect the eyelids in HIV patients, it is **not the most common ocular lesion**. - It presents as a **reddish-purple nodule** or plaque and is an indicator of advanced immunosuppression. *CMV Retinitis* - Cytomegalovirus (CMV) retinitis is a significant and **vision-threatening opportunistic infection** in advanced HIV. - However, it occurs in patients with **severe immunosuppression** (low CD4 counts) and is less common overall than cotton wool spots. *Choroiditis* - Choroiditis, an inflammation of the choroid, can occur in HIV patients due to various opportunistic infections or directly from the virus. - It is **less prevalent** than cotton wool spots and typically requires specific etiologies beyond HIV itself.
Question 56: A patient sustained an eye injury leading to corneal opacification and complete vision loss in the affected eye. Following successful corneal grafting, the patient regained clear vision. According to injury severity classification, this injury would be categorized as:
- A. Non-serious
- B. Serious (Correct Answer)
- C. Critical
- D. Life-threatening
Explanation: ***Serious (Grievous Hurt)*** - According to **IPC Section 320**, an injury causing **permanent privation of sight of either eye** is classified as **grievous hurt** - At the time of injury, the patient had **complete vision loss** due to corneal opacification, which constitutes grievous hurt - In medico-legal classification, **injury severity is determined at the time of examination**, not after treatment outcomes - The fact that vision was later restored through corneal grafting does **not change the initial classification** of the injury - This principle is crucial in forensic medicine: **treatment success does not downgrade injury severity** *Non-serious (Simple Injury)* - Simple injuries are those that do **not fall under the definition of grievous hurt** - Complete vision loss clearly meets the criteria for **grievous hurt** (permanent privation of sight) - Even though vision was eventually restored, the initial injury severity was grievous, not simple *Critical* - Critical injuries typically refer to conditions requiring **immediate intensive care** with uncertain outcomes or multiple organ involvement - While the eye injury was severe, this term is not part of the standard **IPC Section 320 classification** - The correct legal classification for this injury is grievous hurt (serious), not critical *Life-threatening* - Life-threatening injuries pose **imminent danger to life** if untreated - Corneal injury with vision loss, while serious for visual function, does **not endanger life** - This injury falls under **grievous hurt** due to vision loss, not life-threatening category
Question 57: Which optical instrument utilizes the principle of total internal reflection?
- A. Gonioscope (Correct Answer)
- B. Pachymeter
- C. Ophthalmoscope
- D. Lensometer
Explanation: ***Gonioscope*** - A **gonioscope** uses mirrors or prisms to allow visualization of the **anterior chamber angle**, leveraging **total internal reflection** to bypass the normal optical limitations of the cornea. - The principle of total internal reflection occurs when light traveling from a denser medium (like the prism/mirror in the gonioscope) hits an interface with a less dense medium (like air or the aqueous humor) at an angle greater than the **critical angle**, causing all light to reflect back. *Pachymeter* - A **pachymeter** is used to measure the **thickness of the cornea**, typically employing ultrasound or optical methods. - It does not rely on total internal reflection but rather on the time-of-flight of sound waves or the reflection/scattering of light from corneal layers. *Ophthalmoscope* - An **ophthalmoscope** is used to examine the posterior segment of the eye, including the **fundus**, optic disc, and retina. - It works by directing a light source into the eye and viewing the reflected light, using lenses to focus the image, without utilizing total internal reflection. *Lensometer* - A **lensometer** (or focimeter) is an optician's instrument used to measure the prescription of eyeglasses or contact lenses, including **sphere, cylinder, and axis**. - Its operation is based on standard lens optics and does not involve the principle of total internal reflection.
Question 58: Which cells in the retina are primarily affected by methanol toxicity?
- A. Photoreceptor cells
- B. Bipolar cells
- C. Horizontal cells
- D. Ganglion cells of the retina (Correct Answer)
Explanation: ***Ganglion cells of the retina*** - Methanol toxicity, specifically its metabolite **formic acid**, selectively targets and damages **retinal ganglion cells**. - This damage leads to **optic neuropathy** and can cause permanent vision loss or blindness. *Photoreceptor cells* - These cells (rods and cones) are responsible for light detection but are generally **not primarily affected** by methanol toxicity. - While severe toxicity can lead to widespread retinal damage, initial and primary damage is to the ganglion cells. *Bipolar cells* - Bipolar cells transmit signals from photoreceptors to ganglion cells but are **not the primary target** of methanol's toxic effects. - Their damage would typically be secondary to severe, prolonged methanol poisoning. *Horizontal cells* - Horizontal cells are involved in lateral inhibition and signal processing within the retina but are **not selectively vulnerable** to methanol toxicity. - Damage to these cells is not a defining feature of methanol-induced vision loss.
Question 59: Which of the following methods is not used to measure refractive error?
- A. Keratometry
- B. Retinoscopy
- C. Refractometry
- D. Spectrometry (Correct Answer)
Explanation: ***Spectrometry*** - **Spectrometry** measures the absorption or emission of light by a substance at different wavelengths, primarily used for chemical analysis and material science. - It does not directly assess the **focal power** of the eye or its refractive state. *Keratometry* - **Keratometry** measures the curvature of the anterior surface of the cornea, which is essential for determining astigmatism and fitting contact lenses. - While it doesn't measure the entire refractive error, it provides crucial data used in **refractive error assessment**. *Retinoscopy* - **Retinoscopy** is an objective method for determining the eye's refractive error by observing the movement of reflected light in the patient's pupil as a light source is swept across the eye. - It helps determine the approximate sphere and cylinder power needed for proper vision correction, especially useful in **uncooperative patients** or children. *Refractometry* - **Refractometry** (often performed with an autorefractor) is an automated method that uses light reflections from the retina to estimate the eye's refractive error. - It provides an objective measurement of the **spherical, cylindrical, and axial components** of refractive error, serving as a starting point for subjective refraction.