NEET-PG 2018 - Ophthalmology PYQs Practice Questions

Q: Blowout fracture of the orbit most commonly involves?

Floor. ***Floor*** - The **orbital floor** is the most commonly fractured site in a blowout fracture due to its thinness and location, often leading to herniation of orbital contents into the maxillary sinus. - This type of fracture often results from a **sudden increase in intraorbital pressure** by a blunt trauma, causing the weakest part of the orbit to give way. *Medial wall* - While less common than floor fractures, the **medial wall** can also be fractured in a blowout injury, leading to herniation into the ethmoid sinuses. - Involvement of the medial wall can sometimes damage the **lacrimal drainage system** or the medial rectus muscle. *Lateral wall* - The **lateral wall** of the orbit is significantly thicker and more robust than the floor or medial wall, making isolated lateral wall fractures extremely rare. - Fractures of the lateral wall are usually associated with more extensive **zygomaticomaxillary complex (ZMC)** fractures or high-impact trauma. *Roof* - The **orbital roof** is composed of the frontal bone and is considerably stronger and thicker than the floor, making roof fractures uncommon in isolated blowout injuries. - Fractures of the orbital roof typically occur with **severe trauma** and are often associated with intracranial injury or damage to the frontal sinus. [Practice more Ophthalmology PYQs on OnCourse]

Q: Which is an example of Simple Myopic Astigmatism?

plano -2.00 × 90°. ***plano -2.00 × 90°*** - This prescription indicates a **spherical equivalent of zero (plano)** in one meridian and **-2.00 diopters of myopia** in the meridian 90 degrees away. - This perfectly fits the definition of **simple myopic astigmatism**, where one principal meridian is emmetropic and the other is myopic. *+2.00 sphere* - This prescription represents **simple hyperopia**, meaning the eye is **farsighted** but without any astigmatism. - All light rays focus behind the retina, and there is no difference in refractive power between the principal meridians. *-2.00 sphere* - This represents **simple myopia**, where the eye is **nearsighted** but without any astigmatism. - All light rays focus in front of the retina, and there is no difference in refractive power between the principal meridians. *+1.00 -3.00 × 90°* - This prescription is an example of **mixed astigmatism**, where one principal meridian is hyperopic (+1.00 D) and the other is myopic (-2.00 D, calculated as +1.00 + [-3.00]). - This differs from simple myopic astigmatism where one meridian is emmetropic. [Practice more Ophthalmology PYQs on OnCourse]

Q: Patient with eye surgery done 2 days ago presents with pain and dimness of vision. Which of the following is not useful for management?

Topical antibiotics. ***Topical antibiotics*** - This patient presents with symptoms suggestive of **post-surgical endophthalmitis** (pain and dimness of vision after eye surgery), which is a severe infection of the intraocular fluids (vitreous and/or aqueous humor). - Topical antibiotics typically do not achieve sufficient intraocular concentrations to effectively treat a deep-seated infection like endophthalmitis. *Intravenous antibiotics* - **Intravenous antibiotics** can provide systemic coverage and may reach the posterior segment of the eye, although their penetration into the vitreous can be limited. - They are often used as an adjunct to more direct routes of administration in severe endophthalmitis. *Intravitreal antibiotics* - **Intravitreal antibiotics** are injected directly into the vitreous cavity, providing high local concentrations of medication directly at the site of infection. - This is considered a cornerstone of endophthalmitis management due to its immediate and potent antimicrobial effect. *Pars plana vitrectomy* - **Pars plana vitrectomy** involves surgical removal of the infected vitreous, which reduces the bacterial load and inflammatory mediators, and allows for direct sampling for microbiology. - It is particularly indicated in cases of severe endophthalmitis or when there is poor response to antibiotics, often improving visual outcomes. [Practice more Ophthalmology PYQs on OnCourse]

Question 1

Blowout fracture of the orbit most commonly involves?

Accepted Answer

Floor

Answer

Medial wall

Answer

Lateral wall

Answer

Roof

Question 2

Which is an example of Simple Myopic Astigmatism?

Accepted Answer

plano -2.00 × 90°

Answer

+2.00 sphere

Answer

+1.00 -3.00 × 90°

Answer

-2.00 sphere

Question 3

Patient with eye surgery done 2 days ago presents with pain and dimness of vision. Which of the following is not useful for management?

Accepted Answer

Topical antibiotics

Answer

Intravenous antibiotics

Answer

Intravitreal antibiotics

Answer

Pars plana vitrectomy

NEET-PG 2018 — Ophthalmology