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: How is the angle of squint measured?

Prism. ***Prism*** - The **angle of squint**, which indicates the deviation of the eyes, is most accurately measured using **prisms** in conjunction with the **prism cover test** or **alternate prism cover test**. - Prisms quantify the degree of ocular deviation in **prism diopters** by neutralizing the misalignment so that the light falls correctly on the fovea. *Gonioscopy* - This technique is used to examine the **anterior chamber angle** of the eye, which is relevant for diagnosing conditions like **glaucoma**. - It does not involve measuring the angle of ocular deviation or misalignment of the eyes. *Retinoscopy* - Retinoscopy is an objective method to determine the **refractive error** of the eye (e.g., myopia, hyperopia, astigmatism). - While it assesses the eye's ability to focus light, it does not directly measure the angle of a squint. *Keratometry* - Keratometry measures the **curvature of the cornea**, primarily used for fitting contact lenses or calculating intraocular lens power for cataract surgery. - It does not assess the alignment of the eyes or the magnitude of a squint. [Practice more Ophthalmology PYQs on OnCourse]

Q: The 'headlight in fog' appearance is seen in which condition?

Toxoplasmosis. ***Toxoplasmosis*** - The "headlight in fog" appearance is a classic description of **chorioretinitis** caused by **congenital toxoplasmosis**. - It refers to an old, healed **retinal scar** (headlight) surrounded by active inflammation and **vitreous haze** (fog). *Syphilis* - Ocular syphilis can cause various presentations, including uveitis, retinitis, and optic neuropathy, but it does **not typically** present with the specific "headlight in fog" appearance. - Ocular lesions are often more diffuse or involve distinct **gummatous lesions**. *Toxocara* - Ocular toxocariasis often presents as a **granuloma** (either peripheral or macular) or as **endophthalmitis**, but not the characteristic "headlight in fog" pattern. - The lesions are usually a result of a direct larval migration and subsequent inflammatory reaction. *Herpes* - Herpes simplex virus (HSV) or varicella-zoster virus (VZV) can cause **acute retinal necrosis** (ARN) or progressive outer retinal necrosis (PORN), presenting with widespread retinal whitening and vascular occlusion. - These conditions have distinct appearances, generally **lacking the central scar** with surrounding active inflammation seen in "headlight in fog." [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

How is the angle of squint measured?

Accepted Answer

Prism

Answer

Gonioscopy

Answer

Retinoscopy

Answer

Keratometry

Question 5

The 'headlight in fog' appearance is seen in which condition?

Accepted Answer

Toxoplasmosis

Answer

Syphilis

Answer

Toxocara

Answer

Herpes

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

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

Question 8

What is the first sign of iridocyclitis?

Accepted Answer

Aqueous flare

Answer

KP

Answer

Congestion

Answer

Trichiasis

Question 9

Which of the following conditions is least likely to be associated with neovascular glaucoma?

Accepted Answer

Open angle glaucoma

Answer

Diabetes

Answer

CRVO

Answer

Eale's disease

Question 10

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

Accepted Answer

Myopia

Answer

Astigmatism

Answer

Hypermetropia

Answer

Presbyopia

NEET-PG 2012 — Ophthalmology