NEET-PG 2012 - Ophthalmology PYQs Practice Questions

Q: What is the MOST common cause of amblyopia?

Strabismus. ***Strabismus*** - **Strabismic amblyopia** is the **MOST common cause of amblyopia**, accounting for approximately **50% of cases**. - When the eyes are misaligned, the brain suppresses the image from the deviating eye to avoid **diplopia** (double vision). - The prolonged suppression during the critical period of visual development leads to poor visual acuity in the affected eye. - Early detection and treatment (occlusion therapy, correction of refractive errors, alignment surgery) are crucial. *Refractive errors* - **Refractive amblyopia**, particularly **anisometropia** (significant difference in refractive power between eyes), is the **second most common cause**. - The brain suppresses the blurry image from the eye with greater refractive error, leading to poor visual development. - **Bilateral high refractive errors** (isoametropic amblyopia) can also cause amblyopia, though less commonly than anisometropia. *Cataracts* - **Deprivation amblyopia** results from obstruction of the visual axis (congenital cataract, ptosis, corneal opacity). - This is a **less common but more severe** form of amblyopia requiring urgent treatment. - If untreated during the critical period, it can cause **irreversible vision loss**. *None of the options* - Incorrect, as strabismus is a well-established and the most common cause of amblyopia. [Practice more Ophthalmology PYQs on OnCourse]

Q: Features of vernal conjunctivitis are:

All of the options. ***All of the options*** - **Vernal conjunctivitis (VKC)** is a severe form of allergic conjunctivitis characterized by chronic inflammation of the conjunctiva, impacting the cornea in advanced stages. - **Shield ulcers**, **Horner-Trantas dots**, and **papillary hypertrophy** are all classic clinical features observed in VKC. *Shield ulcer* - This is a **corneal complication** of severe vernal conjunctivitis, characterized by epithelial defects that can lead to significant pain and vision impairment. - It develops due to corneal abrasion from the giant papillae on the upper tarsal conjunctiva and direct corneal toxicity from inflammatory mediators. *Horner-Trantas spots* - These are **gelatinous aggregations** of epithelial cells and eosinophils that appear as white dots at the limbus, particularly evident at the superior limbus. - They are one of the **pathognomonic signs** of vernal conjunctivitis, indicating significant allergic inflammation. *Papillary hypertrophy* - Characterized by the development of **large, flattened papillae** (often described as "cobblestone" papillae) on the upper tarsal conjunctiva. - This hypertrophy is a result of chronic inflammation and proliferation of mast cells, eosinophils, and lymphocytes in the conjunctival stroma. [Practice more Ophthalmology PYQs on OnCourse]

Q: Which of the following organisms can penetrate a normal intact cornea?

Gonococcus. ***Gonococcus*** - *Neisseria gonorrhoeae* is unique among bacteria in its ability to directly penetrate the **intact corneal epithelium**. - This characteristic makes it a highly virulent cause of **rapidly progressive corneal ulceration** and endophthalmitis, especially in neonates born to infected mothers. *Staphylococcus aureus* - *Staphylococcus aureus* typically requires some form of **corneal epithelial defect** (e.g., abrasion, foreign body) to invade and cause keratitis. - While it is a common cause of bacterial keratitis, it does not penetrate an **undamaged cornea**. *Streptococcus pneumoniae* - Similar to *S. aureus*, *Streptococcus pneumoniae* usually needs a **breach in the corneal epithelium** to establish an infection. - It is a frequent cause of **bacterial conjunctivitis** and keratitis but is not known for invading an intact cornea. *Listeria monocytogenes* - *Listeria monocytogenes* is an important human pathogen but is primarily known for causing **meningitis, sepsis, and perinatal infections**. - It is not a common cause of bacterial keratitis, and there is no evidence to suggest it can penetrate an **intact corneal surface**. [Practice more Ophthalmology PYQs on OnCourse]

Q: What type of refractive error is astigmatism, which is characterized by non-spherical curvature of the cornea or lens?

Curvatural ametropia. ***Curvatural ametropia*** - Astigmatism, due to its **irregular corneal or lenticular curvature**, falls under the category of curvatural ametropia. - This type of ametropia occurs when the **optical power of the eye varies in different meridians**, leading to light focusing at multiple points rather than a single focal point. *Spherical aberration* - **Spherical aberration** is an optical error where light rays passing through the periphery of a lens focus at a different point than those passing through the center. - It results in a **loss of image clarity** but is distinct from astigmatism's power variation across meridians. *Axial ametropia* - **Axial ametropia** refers to refractive errors caused by an abnormal **length of the eyeball** (either too long or too short). - **Myopia** and **hyperopia** are primary examples of axial ametropia, where the eyeball length dictates whether light focuses in front of or behind the retina, respectively. *Index ametropia* - **Index ametropia** arises from variations in the **refractive index of the ocular media**, such as the cornea, lens, or vitreous humor. - Changes in the refractive index can alter how light bends, but astigmatism is primarily due to surface curvature, not changes in media refractive index. [Practice more Ophthalmology PYQs on OnCourse]

Q: Foster's Fuchs spots are specifically associated with which condition?

Myopia. ***Myopia*** - **Foster's-Fuchs spots** are a pathognomonic finding in **pathologic myopia**, characterized by subretinal neovascularization and hemorrhage at the macula. - This condition is associated with high degrees of **myopia** (nearsightedness), leading to thinning and stretching of the retina and choroid. - The spots represent **pigmented scars** from resolved choroidal neovascular membrane hemorrhages. *Hypermetropia* - **Hypermetropia** (farsightedness) does not typically lead to Foster's-Fuchs spots; these spots are specific to the degenerative changes seen in high myopia. - Ocular complications in hypermetropia are different and may include **angle-closure glaucoma** or **accommodative esotropia**. *Astigmatism* - **Astigmatism** is an optical defect where the eye fails to focus light equally on the entire retina, causing blurred vision at any distance. - It is not associated with the development of **Foster's-Fuchs spots**, which are a specific macular degeneration seen in myopia. *Presbyopia* - **Presbyopia** is the age-related loss of accommodation due to decreased lens elasticity. - It is a physiological change and is not associated with **Foster's-Fuchs spots** or the structural changes seen in pathologic myopia. [Practice more Ophthalmology PYQs on OnCourse]

Question 1

What is the MOST common cause of amblyopia?

Accepted Answer

Strabismus

Answer

Cataracts

Answer

Refractive errors

Answer

None of the options

Question 2

Features of vernal conjunctivitis are:

Accepted Answer

All of the options

Answer

Papillary hypertrophy

Answer

Horner-Trantas spots

Answer

Shield ulcer

Question 3

Which of the following organisms can penetrate a normal intact cornea?

Accepted Answer

Gonococcus

Answer

Staphylococcus aureus

Answer

Streptococcus pneumoniae

Answer

Listeria monocytogenes

Question 4

What type of refractive error is astigmatism, which is characterized by non-spherical curvature of the cornea or lens?

Accepted Answer

Curvatural ametropia

Answer

Spherical aberration

Answer

Index ametropia

Answer

Axial ametropia

Question 5

Foster's Fuchs spots are specifically associated with which condition?

Accepted Answer

Myopia

Answer

Astigmatism

Answer

Hypermetropia

Answer

Presbyopia

Question 6

How is dioptric power related to focal length?

Accepted Answer

Inversely to focal length

Answer

Directly to square of focal length

Answer

Directly to focal length

Answer

Inversely to square of focal length

Question 7

Which of the following is a known complication of vernal keratoconjunctivitis?

Accepted Answer

Keratoconus

Answer

Retinal detachment

Answer

Vitreous hemorrhage

Answer

Cataract

Question 8

What is the definition of the visual axis in relation to the eye?

Accepted Answer

Line from the object to the fovea

Answer

Line from the center of the lens to the cornea

Answer

Line from the center of the cornea to the center of the lens

Answer

None of the options

Question 9

Satellite nodules are typically associated with which of the following conditions?

Accepted Answer

Fungal corneal ulcer

Answer

Tuberculosis

Answer

Sarcoidosis

Answer

Viral ulcer

Question 10

The reduced effect of low astigmatism in dim light is primarily due to:

Accepted Answer

Pupil constriction

Answer

Pupil dilatation

Answer

Increased curvature of lens

Answer

Decreased curvature of lens

NEET-PG 2012 — Ophthalmology