NEET-PG 2013 - Ophthalmology Practice Questions

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.

Q: Arcuate field defect akin to glaucoma is seen in?

Optic nerve lesion. ***Optic nerve lesion*** - An **arcuate field defect** is a specific pattern of visual field loss that follows the course of nerve fibers in the retina and is characteristic of **optic nerve damage**, similar to what is seen in glaucoma. - This type of defect is due to damage to the **bundle of retinal nerve fibers** that arch above or below the macula, often causing a scotoma (blind spot) that respects the horizontal meridian. - Common causes include **anterior ischemic optic neuropathy (AION)**, **optic neuritis**, and other optic nerve pathologies that affect the nerve fiber layer. *Pituitary adenoma* - A pituitary adenoma typically causes a **bitemporal hemianopsia** due to compression of the optic chiasm. - This visual field defect involves the lateral halves of both visual fields, which is different from an arcuate defect. *Posterior cerebral artery infarct* - An infarct in the posterior cerebral artery typically leads to a **homonymous hemianopsia** (loss of half of the visual field on the same side in both eyes) or a quadrantanopsia. - This type of defect results from damage to the **visual cortex** or optic radiations, not the optic nerve itself in a glaucoma-like pattern. *None of the options* - This is incorrect because **optic nerve lesion** is a valid and correct answer. - Optic nerve pathologies are well-established causes of arcuate field defects similar to those seen in glaucoma.

Q: Binocular single vision is tested by?

Synoptophore. ***Synoptophore*** - The **synoptophore** is an ophthalmic instrument used to diagnose and treat various binocular vision anomalies, including **strabismus** and suppression. - It allows for the precise measurement and assessment of the eyes' ability to **fuse images** from both eyes into a single perception, which is the essence of **binocular single vision**. *Amsler grid* - The **Amsler grid** is primarily used to detect central visual field defects, such as those caused by **macular degeneration** or other retinal pathologies. - It does not directly assess the brain's ability to fuse images from both eyes into a single vision. *Cardboard test* - The "cardboard test" is not a standard ophthalmic test for binocular single vision. - It may refer to various informal or rudimentary tests, but it lacks the precision and standardization required for accurate assessment of binocular functions. *Maddox rod* - The **Maddox rod** is used to detect and measure **heterophoria** (latent strabismus) or **heterotropia** (manifest strabismus). - It dissociates the images seen by each eye, preventing fusion and revealing the deviation of the eyes, rather than directly testing the ability to achieve binocular single vision.

Q: From which surface is the Purkinje IV image formed?

Posterior surface of lens. ***Posterior surface of lens*** - The **Purkinje IV image** is formed by reflection from the **posterior surface of the lens**, which is the most curved surface in the eye. - Due to the higher curvature and refractive index difference, this surface acts as a concave mirror, producing an **inverted, virtual image**. *Anterior surface of cornea* - The **Purkinje I image** is formed from the **anterior surface of the cornea**, which is the primary reflective surface of the eye. - This image is **bright, erect, and virtual**, serving as a basic reference for eye position. *Posterior surface of cornea* - The **Purkinje II image** originates from the **posterior surface of the cornea**, a much less curved and reflective surface than the anterior. - This image is typically **fainter** and less frequently used in clinical assessments due to its reduced visibility. *Anterior surface of lens* - The **Purkinje III image** is generated by reflection from the **anterior surface of the lens**. - This image is **inverted and virtual**, and its movement relative to Purkinje I can indicate lens accommodation changes.

Q: Stocker's line is seen in?

Pterygium. **Pterygium** - **Stocker's line** is a **ferrous deposit** that appears as a brown or yellow line at the leading edge of a **pterygium**. - Its presence signifies the progressive nature of the pterygium, indicating ongoing iron deposition due to chronic epithelial degeneration and remodeling. *Glaucoma* - Glaucoma is characterized by **optic nerve damage** and **visual field loss**, usually associated with elevated intraocular pressure. - It does not involve the formation of Stocker's line, which is a corneal or conjunctival finding. *Posterior scleritis* - Posterior scleritis is an **inflammation of the sclera** behind the equator of the globe, often presenting with pain, vision loss, or choroidal folds. - It does not involve the characteristic Stocker's line, which is specific to pterygium. *Diabetic retinopathy* - Diabetic retinopathy involves **microvascular damage** to the retina, leading to vision loss, and is characterized by microaneurysms, hemorrhages, and neovascularization. - It is a retinal disease and does not present with Stocker's line.

Q: Which of the following conditions is NOT diagnosed by fluorescein angiography?

Hypertensive retinopathy. ***Hypertensive retinopathy*** - This condition is primarily diagnosed by **clinical fundoscopic examination**, not fluorescein angiography - Diagnosis is based on characteristic clinical findings: **arteriovenous nicking, copper/silver wire arterioles, cotton-wool spots, flame-shaped hemorrhages, and papilledema** in severe cases - **Fluorescein angiography** is rarely needed and only used in research settings or to assess severe complications; it is **not a standard diagnostic tool** for hypertensive retinopathy *Diabetic retinopathy* - **Fluorescein angiography** is extensively used for diagnosing and staging diabetic retinopathy - It helps identify **microaneurysms, capillary non-perfusion areas, macular edema, and neovascularization** - Essential for detecting **proliferative diabetic retinopathy** and planning laser photocoagulation *Central serous retinopathy* - **Fluorescein angiography** shows characteristic **"smokestack" or "inkblot" pattern** of leakage at the RPE level - Demonstrates one or more **leakage points** with progressive pooling of dye in the subretinal space - While **OCT** is now preferred for initial diagnosis, FA remains valuable for identifying leakage sites and guiding treatment *Choroidal neovascularization* - **Fluorescein angiography** is the gold standard for diagnosing **choroidal neovascularization (CNV)** - Shows **early hyperfluorescence with progressive leakage** from abnormal vessels - Critical for determining the **type (classic vs occult), location, and extent** of CNV for treatment planning

Q: In photophthalmia, which part of the eye is primarily affected?

Cornea. ***Cornea*** - **Photophthalmia** (also known as **snow blindness** or **arc eye**) is caused by overexposure to **ultraviolet (UV) light**, which primarily damages the **corneal epithelium**. - This damage leads to **superficial punctate keratitis**, characterized by pain, foreign body sensation, photophobia, and blurred vision. - Symptoms typically appear **6-12 hours after exposure** and resolve within **24-48 hours** with supportive care. *Retina* - The **retina** can be damaged by certain types of light (e.g., solar retinopathy from looking at the sun), but **UV light** in photophthalmia is largely absorbed by the anterior structures of the eye, particularly the cornea. - Retinal damage would typically present with **central visual loss** or **scotomas**, differing from the acute pain and photophobia of photophthalmia. *Optic nerve* - The **optic nerve** transmits visual information from the retina to the brain and is generally not directly affected by **UV light exposure** causing photophthalmia. - Optic nerve issues would manifest as severe **vision loss**, **pupillary abnormalities**, or **pain with eye movement**, which are not typical for photophthalmia. *Lens* - While chronic **UV exposure** can contribute to **cataract formation** in the lens over time, this is a long-term effect, not the acute primary damage seen in photophthalmia. - The acute presentation of photophthalmia with severe pain, photophobia, and foreign body sensation is characteristic of **corneal epithelial damage**, not lens involvement.

Q: Phlyctenular conjunctivitis is primarily associated with hypersensitivity to which of the following?

Staphylococcus. ***Staphylococcus*** - **Phlyctenular conjunctivitis** is characterized by delayed (Type IV) hypersensitivity reactions to bacterial antigens, most commonly from **Staphylococcus aureus**. - This condition often presents with small, nodular lesions (phlyctenules) on the conjunctiva or cornea, which are essentially collections of inflammatory cells responding to bacterial proteins. - **Important note**: **Mycobacterium tuberculosis** is another well-documented cause of phlyctenular conjunctivitis, particularly in TB-endemic regions, and should be considered in the differential diagnosis. - Other triggers include protein antigens from organisms colonizing the ocular surface. *Chlamydia* - While **Chlamydia trachomatis** can cause chronic conjunctivitis (e.g., trachoma, adult inclusion conjunctivitis), it does not typically lead to the distinct nodular lesions seen in phlyctenular conjunctivitis. - Ocular chlamydial infections are primarily characterized by follicular conjunctivitis and pannus formation. *Pneumococcus* - **Streptococcus pneumoniae** (Pneumococcus) is a common cause of acute bacterial conjunctivitis, characterized by purulent discharge and redness. - However, it is not associated with the specific delayed hypersensitivity reaction that defines phlyctenular conjunctivitis. *Aspergillus* - **Aspergillus** species are fungi and are more commonly implicated in fungal keratitis or allergic bronchopulmonary aspergillosis, particularly in immunocompromised individuals. - Fungal infections of the conjunctiva are rare and do not typically manifest as phlyctenular conjunctivitis.

Q: Normal level of visual acuity is attained at which age

6 years. ***6 years*** - **Normal adult visual acuity (20/20 or 6/6)** is typically achieved around the age of **6 years** as the visual system fully matures. - This age allows for the complete development of **foveal vision** and **binocular functions**. *6 months* - At 6 months of age, an infant's visual acuity is still developing and is typically around **20/200 to 20/400**. - While significant visual development occurs by this age, including **face recognition and tracking objects**, it is not yet at adult levels. *1 year* - By one year, visual acuity improves to approximately **20/50 to 20/100**. - Infants at this age are able to **distinguish fine details** and have improved **depth perception**, but full maturity is still some years away. *3 years* - At 3 years of age, visual acuity is generally around **20/30 to 20/40**. - Children at this stage are able to perform **visual tasks** like drawing and recognizing letters, but subtle refinements are still ongoing.

Question 1

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 2

Arcuate field defect akin to glaucoma is seen in?

Accepted Answer

Optic nerve lesion

Answer

Pituitary adenoma

Answer

Posterior cerebral artery infarct

Answer

None of the options

Question 3

Binocular single vision is tested by?

Accepted Answer

Synoptophore

Answer

Amsler grid

Answer

Cardboard test

Answer

Maddox rod

Question 4

From which surface is the Purkinje IV image formed?

Accepted Answer

Posterior surface of lens

Answer

Anterior surface of cornea

Answer

Posterior surface of cornea

Answer

Anterior surface of lens

Question 5

Stocker's line is seen in?

Accepted Answer

Pterygium

Answer

Glaucoma

Answer

Posterior scleritis

Answer

Diabetic retinopathy

Question 6

Which of the following conditions is NOT diagnosed by fluorescein angiography?

Accepted Answer

Hypertensive retinopathy

Answer

Diabetes retinopathy

Answer

Central serous retinopathy

Answer

Choroidal neovascularization

Question 7

All statements are true about trachoma except:

Accepted Answer

Marked papillary hyperplasia with limbal follicles are seen in stage III

Answer

Strains mainly responsible are A, B, Ba and C

Answer

Trachoma is caused by bedsonian organism of psittacosis - lymphogranuloma - trachoma (PLT) group.

Answer

Corneal ulceration is a complication

Question 8

In photophthalmia, which part of the eye is primarily affected?

Accepted Answer

Cornea

Answer

Lens

Answer

Retina

Answer

Optic nerve

Question 9

Phlyctenular conjunctivitis is primarily associated with hypersensitivity to which of the following?

Accepted Answer

Staphylococcus

Answer

Chlamydia

Answer

Pneumococcus

Answer

Aspergillus

Question 10

Normal level of visual acuity is attained at which age

Accepted Answer

6 years

Answer

6 months

Answer

1 year

Answer

3 years

NEET-PG 2013 — Ophthalmology