FMGE 2018 - Ophthalmology Practice Questions

Q: Blow out fracture can be due to:

Tennis ball injury. ***Tennis ball injury*** - A tennis ball injury to the orbit can cause a **blowout fracture** due to either direct impact compressing the globe or hydraulic pressure from the ball transmission of force, leading to a fracture of the orbital floor or medial wall. - The impact forces the orbital contents posteriorly, increasing intraorbital pressure which in turn causes the weakest bony walls (usually the floor or medial wall) to fracture outwards into the maxillary or ethmoid sinuses, respectively. *Punch at the chin from below* - A punch to the chin from below typically results in fractures of the **mandible**, particularly the condyles or angle. - This mechanism does not directly transmit force to the orbital rim or globe in a way that would cause a classic blowout fracture. *Sudden fall* - A sudden fall can cause various types of fractures depending on the impact site, but it is not a specific or common mechanism for a **blowout fracture**. - Falls usually lead to fractures of the extremities, hips, or skull other than the orbit, depending on how the body impacts the ground. *Chisel and hammer injury* - A chisel and hammer injury would more likely cause a **localized, penetrating injury** or a focal fracture at the point of impact on the face or skull. - This type of injury does not typically generate the diffuse hydraulic pressure within the orbit needed to cause a **blowout fracture** of the orbital floor or medial wall.

Q: Which of the following is true about pterygium?

Conjunctival invasion making a flap over cornea. ***Conjunctival invasion making a flap over cornea*** - A **pterygium** is characterized by the growth of **fibrovascular tissue** from the conjunctiva onto the cornea. - This growth typically forms a **triangular flap**, with its apex extending towards the center of the corneal surface. *Fatty deposition of sclera* - This description is more indicative of **pinguecula**, which is a **yellowish, fatty deposit** on the conjunctiva, usually on the nasal side, but it does not invade the cornea. - Unlike pterygium, a **pinguecula** remains confined to the conjunctiva and does not grow across the limbus onto the cornea. *Inflammation of cornea* - While a pterygium can sometimes cause irritation or inflammation, its primary characteristic is a **degenerative growth of tissue**, not primarily an inflammatory condition of the cornea itself. - **Keratitis** refers to inflammation of the cornea, which can have various causes, but it is not the defining feature of pterygium. *Dead epithelial debris accumulation* - The accumulation of dead epithelial debris is not the principal histological feature of a pterygium. - Pterygium involves **hyperplasia of conjunctival epithelium** and **subepithelial fibrovascular tissue growth**, not merely dead cell accumulation.

Q: Average hypermetropia in a newborn is

+ 2.5 D. ***+ 2.5 D*** - Most **newborns** are **hypermetropic** (farsighted) due to a shorter axial length of the eye. - The average hypermetropic correction needed at birth is approximately **+2.5 diopters (D)**. *+ 10 D* - A hyperopia of **+10 D** would represent a very significant degree of **hypermetropia**, far exceeding the typical physiological range for a newborn. - Such high hyperopia in a newborn might suggest an **ocular anomaly** or a condition like **microphthalmia**. *+ 1 D* - A hyperopia of **+1 D** is a mild degree of hypermetropia, which is less than the average physiological hyperopia found in **newborns**. - While within a normal range for some infants, it does not represent the typical average for **newborns**. *+ 5 D* - A hyperopia of **+5 D** is a higher degree of hypermetropia than the average seen in **newborns**. - While possible, it is not the most common or average refractive error at birth, which is typically around **+2.5 D**.

Question 1

Blow out fracture can be due to:

Accepted Answer

Tennis ball injury

Answer

Punch at the chin from below

Answer

Sudden fall

Answer

Chisel and hammer injury

Question 2

Which of the following is true about pterygium?

Accepted Answer

Conjunctival invasion making a flap over cornea

Answer

Fatty deposition of sclera

Answer

Inflammation of cornea

Answer

Dead epithelial debris accumulation

Question 3

Average hypermetropia in a newborn is

Accepted Answer

+ 2.5 D

Answer

+ 10 D

Answer

+ 1 D

Answer

+ 5 D

FMGE 2018 — Ophthalmology