NEET-PG 2013 - Ophthalmology PYQs Practice Questions

Q: Cataract is caused by all except:

MRI. ***MRI*** - Magnetic Resonance Imaging (MRI) uses powerful **magnetic fields** and radio waves to generate images, which are not known to cause cataracts. - The energy used in MRI is **non-ionizing** and does not directly damage lens proteins. *Ultraviolet radiation* - Prolonged exposure to **UV-B radiation** is a significant risk factor for the development of various types of cataracts, especially cortical and posterior subcapsular cataracts. - UV radiation can cause oxidative damage to lens proteins and lipids, leading to their aggregation and opacification. *Infrared radiation* - Chronic exposure to high levels of **infrared (IR) radiation**, such as that experienced by glassblowers or steelworkers, can lead to "glassblower's cataract" or "heat cataract." - IR radiation causes thermal damage to the lens, particularly the anterior capsule and subcapsular region. *Microwave radiation* - High-intensity **microwave radiation** has been implicated in the formation of cataracts, particularly in occupational exposure scenarios. - It causes thermal effects within the lens due to absorption of energy, leading to protein denaturation and opacification. [Practice more Ophthalmology PYQs on OnCourse]

Q: Attachment of the vitreous is strongest at?

Across ora serrata. ***Across ora serrata*** - The **vitreous base** is a 3-4 mm wide circumferential band extending approximately 2 mm anterior and 2 mm posterior to the **ora serrata**, where the vitreous firmly adheres to the **non-pigmented ciliary epithelium** and the **peripheral retina**. - This strong adhesion makes the **vitreous base** the primary point of vitreous attachment, often remaining attached even during significant vitreous detachments. *Foveal region* - While there is some attachment, the vitreous is typically **less firmly adherent** to the foveal region compared to the vitreous base. - Vitreous detachment from the fovea is a common event, rarely leading to significant tearing or strong adherence. *Back of lens* - The vitreous has a weak attachment to the posterior capsule of the lens, known as the **Wieger's ligament** or **hyaloideocapsular ligament**. - This attachment typically **loses strength with age** and is not the strongest overall point of attachment. *Margin of optic disc* - The vitreous attaches to the margin of the optic disc, forming a circular adhesion called the **peripapillary ring**. - This attachment is **less strong** than the vitreous base and is often the first region from which the vitreous detaches during a **posterior vitreous detachment (PVD)**. [Practice more Ophthalmology PYQs on OnCourse]

Q: Large, white keratic precipitates (mutton-fat KPs) are characteristically seen in?

Granulomatous uveitis. ***Granulomatous uveitis*** - **Mutton-fat keratic precipitates (KPs)** are large, greasy-appearing white deposits on the corneal endothelium, characteristic of **granulomatous inflammation**. - These KPs are composed of macrophages and epithelioid cells, reflecting a **chronic, cell-mediated immune response** seen in granulomatous conditions. *Hemorrhagic uveitis* - This condition involves significant **intraocular bleeding**, which would manifest as hyphema or vitreous hemorrhage, not mutton-fat KPs. - While inflammation may be present, the defining feature is blood, which obscures vision differently than KPs. *Old healed uveitis* - After uveitis heals, KP morphology can change, often appearing smaller, more pigmented, or forming distinct patterns such as **Arlt's triangle**, but not typically actively large, white mutton-fat KPs. - Healed KPs often reflect a less active or resolved inflammatory process, unlike fresh mutton-fat KPs. *Acute anterior uveitis* - This typically presents with smaller, finer, and more numerous **non-granulomatous KPs** (sometimes called "stellate KPs"), in contrast to the large, greasy mutton-fat KPs. - The inflammation is usually acute and less focally organized compared to granulomatous forms. [Practice more Ophthalmology PYQs on OnCourse]

Q: What is the distance of the medial rectus from the limbus?

5.5 mm. ***5.5 mm*** - The **medial rectus muscle** inserts into the sclera at an average distance of **5.5 mm** from the limbus [1]. - This distance is an important anatomical landmark in **ophthalmic surgery** and ocular motility studies. - The insertion distances follow the **Spiral of Tillaux** pattern. *4.5 mm* - This distance does **not correspond** to any of the standard rectus muscle insertion points. - The closest insertion is the **medial rectus at 5.5 mm**, followed by the **inferior rectus at 6.5 mm** [1]. *7.0 mm* - This distance corresponds to the insertion point of the **lateral rectus muscle** from the limbus [1]. - It is the **second farthest insertion point** among the recti muscles. *10 mm* - This distance is incorrect for any of the **rectus muscle insertions** from the limbus. - The rectus muscles insert at varying distances following the **Spiral of Tillaux**: medial (5.5 mm), inferior (6.5 mm), lateral (7.0 mm), and superior (7.7 mm). [Practice more Ophthalmology PYQs on OnCourse]

Q: Which of the following statements about the c-wave in electroretinogram (ERG) is most accurate?

The 'c' wave is a slow positive wave.. ***The 'c' wave is a slow positive wave.*** - The **c-wave** in an ERG is generated by the **retinal pigment epithelium (RPE)** and is characterized by its **slow, positive deflection**. - It reflects the **hyperpolarization** of the RPE cells in response to light stimulation. *The 'c' wave is a negative wave.* - This statement is incorrect because the **c-wave** is consistently observed as a **positive deflection** in the ERG tracing. - A negative wave like the **a-wave** is generated by photoreceptor hyperpolarization, which is a different component. *The 'b' wave arises primarily from photoreceptors.* - The **b-wave** primarily arises from the **Müller cells** and **bipolar cells**, not directly from photoreceptors. - Photoreceptor activity is primarily reflected in the **a-wave**. *The 'a' wave is a positive wave.* - The **a-wave** is a **negative deflection** in the ERG, representing the **hyperpolarization of photoreceptors** in response to light. - It is the earliest component of the ERG waveform. [Practice more Ophthalmology PYQs on OnCourse]

Question 1

Cataract is caused by all except:

Accepted Answer

MRI

Answer

Ultraviolet radiation

Answer

Infrared radiation

Answer

Microwave radiation

Question 2

Attachment of the vitreous is strongest at?

Accepted Answer

Across ora serrata

Answer

Foveal region

Answer

Back of lens

Answer

Margin of optic disc

Question 3

Large, white keratic precipitates (mutton-fat KPs) are characteristically seen in?

Accepted Answer

Granulomatous uveitis

Answer

Hemorrhagic uveitis

Answer

Old healed uveitis

Answer

Acute anterior uveitis

Question 4

What is the distance of the medial rectus from the limbus?

Accepted Answer

5.5 mm

Answer

4.5 mm

Answer

7.0 mm

Answer

10 mm

Question 5

Which of the following statements about the c-wave in electroretinogram (ERG) is most accurate?

Accepted Answer

The 'c' wave is a slow positive wave.

Answer

The 'c' wave is a negative wave.

Answer

The 'b' wave arises primarily from photoreceptors.

Answer

The 'a' wave is a positive wave.

Question 6

Which of the following is NOT a feature of CMV retinitis?

Accepted Answer

Cracked mud appearance

Answer

Perivasculitis

Answer

Brush-fire appearance

Answer

Immunosuppression

Question 7

All are parts of anterior segment of eye except?

Accepted Answer

Vitreous

Answer

Lens

Answer

Cornea

Answer

Aqueous humor

Question 8

Retinitis pigmentosa is characterized by ?

Accepted Answer

Loss of peripheral vision

Answer

Loss of central vision

Answer

Visual field constriction

Answer

Tubular vision

Question 9

What is the thinnest portion of the sclera?

Accepted Answer

Posterior to the rectus muscle insertion

Answer

Anterior to the rectus muscle insertion

Answer

At the posterior pole

Answer

At the limbus

Question 10

The most common cause of vitreous hemorrhage in adults is

Accepted Answer

Diabetes

Answer

Retinal hole

Answer

Trauma

Answer

Hypertension

NEET-PG 2013 — Ophthalmology