NEET-PG 2013 — Ophthalmology

Q: Cataract is caused by all except:

MRI. ***MRI*** - Magnetic Resonance Imaging (MRI) uses powerful **magnetic fields** and radio waves to generate images, which are not known to cause cataracts. - The energy used in MRI is **non-ionizing** and does not directly damage lens proteins. *Ultraviolet radiation* - Prolonged exposure to **UV-B radiation** is a significant risk factor for the development of various types of cataracts, especially cortical and posterior subcapsular cataracts. - UV radiation can cause oxidative damage to lens proteins and lipids, leading to their aggregation and opacification. *Infrared radiation* - Chronic exposure to high levels of **infrared (IR) radiation**, such as that experienced by glassblowers or steelworkers, can lead to "glassblower's cataract" or "heat cataract." - IR radiation causes thermal damage to the lens, particularly the anterior capsule and subcapsular region. *Microwave radiation* - High-intensity **microwave radiation** has been implicated in the formation of cataracts, particularly in occupational exposure scenarios. - It causes thermal effects within the lens due to absorption of energy, leading to protein denaturation and opacification. [Practice more Ophthalmology PYQs on OnCourse]

Q: Large, white keratic precipitates (mutton-fat KPs) are characteristically seen in?

Granulomatous uveitis. ***Granulomatous uveitis*** - **Mutton-fat keratic precipitates (KPs)** are large, greasy-appearing white deposits on the corneal endothelium, characteristic of **granulomatous inflammation**. - These KPs are composed of macrophages and epithelioid cells, reflecting a **chronic, cell-mediated immune response** seen in granulomatous conditions. *Hemorrhagic uveitis* - This condition involves significant **intraocular bleeding**, which would manifest as hyphema or vitreous hemorrhage, not mutton-fat KPs. - While inflammation may be present, the defining feature is blood, which obscures vision differently than KPs. *Old healed uveitis* - After uveitis heals, KP morphology can change, often appearing smaller, more pigmented, or forming distinct patterns such as **Arlt's triangle**, but not typically actively large, white mutton-fat KPs. - Healed KPs often reflect a less active or resolved inflammatory process, unlike fresh mutton-fat KPs. *Acute anterior uveitis* - This typically presents with smaller, finer, and more numerous **non-granulomatous KPs** (sometimes called "stellate KPs"), in contrast to the large, greasy mutton-fat KPs. - The inflammation is usually acute and less focally organized compared to granulomatous forms. [Practice more Ophthalmology PYQs on OnCourse]

Q: Which of the following conditions is least likely to cause proptosis?

Myxoedema. ***Myxoedema*** - **Myxoedema** is associated with severe **hypothyroidism** and is characterized by non-pitting edema due to the accumulation of **glycosaminoglycans** in tissues. - While it can cause facial puffiness, it is **least likely** to cause **proptosis** as there is no direct mechanism for an increase in orbital contents to push the eye forward. *Grave's disease* - **Grave's disease** is the most common cause of **proptosis** due to **immune-mediated inflammation** and accumulation of **glycosaminoglycans** and fat in the orbital tissues, leading to expansion. - This condition specifically affects the **extraocular muscles** and fat, causing bulging of the eyes. *Sarcoidosis* - **Orbital sarcoidosis** can cause **proptosis** due to the formation of **granulomas** within the orbit, leading to mass effect and inflammation. - It can affect any part of the eye and orbit, leading to varied clinical presentations including axial or non-axial globe displacement. *Pituitary adenoma* - A **pituitary adenoma** itself does not directly cause proptosis as it is located in the **sella turcica**, posterior to the orbits. - However, **large adenomas** can cause proptosis indirectly if they invade the **cavernous sinus** and obstruct venous return from the orbit, or if they are associated with **acromegaly**, which can lead to bony overgrowth of the orbital structures and surrounding tissues. [Practice more Ophthalmology PYQs on OnCourse]

Q: What is the normal aqueous production rate in the human eye?

2 µl/min. ***2 µl/min*** - The ciliary body in the human eye continuously produces **aqueous humor** at a typical rate of approximately **2.0-3.0 µl/min**. - This rate is crucial for maintaining **intraocular pressure (IOP)** and providing nutrients to avascular eye structures like the **cornea** and **lens**. - This translates to approximately **3-4 ml per day** of aqueous humor production. *2 ml/min* - This rate is significantly **higher** than the actual production of aqueous humor, which is measured in microliters per minute. - Such a high production rate would lead to a rapid and severe increase in **intraocular pressure**, causing damage to the eye. *5 ml/min* - This value is an **excessively high** rate of fluid production and is not physiologically correct for aqueous humor. - It would result in unsustainable and damaging **intraocular pressure** levels. *5 µl/min* - While closer to the correct order of magnitude, **5 µl/min** is generally considered to be at the higher end or slightly above the average physiological range for aqueous humor production. - Most sources cite the normal range as being between **2-3 µl/min**. [Practice more Ophthalmology PYQs on OnCourse]

Q: Maximum correction of myopia can be done by?

LASIK. ***LASIK*** - **LASIK (Laser-Assisted In Situ Keratomileusis)** allows for significant correction of high myopia by reshaping the cornea with an excimer laser. - It involves creating a **corneal flap** and then ablating tissue underneath, offering precise and stable vision correction for a wide range of refractive errors. - Among the given corneal refractive procedures, LASIK can correct myopia up to **-10 to -12 D**. *Radial keratotomy* - **Radial keratotomy (RK)** involves making radial incisions in the cornea to flatten it, primarily used for low to moderate myopia (up to -3 to -4 D). - It has a higher risk of **unpredictable outcomes**, induced astigmatism, and glare compared to modern laser procedures. *Photorefractive keratectomy* - **Photorefractive keratectomy (PRK)** involves direct ablation of the corneal surface without creating a flap, which is suitable for moderate myopia (up to -8 to -10 D). - While effective, PRK typically has a **longer recovery period** and more post-operative pain than LASIK. *Orthokeratology* - **Orthokeratology (Ortho-K)** uses specially designed rigid contact lenses worn overnight to temporarily reshape the cornea and correct myopia. - The effect is **temporary**, requiring continuous lens wear to maintain vision correction, and is generally limited to low to moderate myopia (up to -4 to -6 D). [Practice more Ophthalmology PYQs on OnCourse]

70 Previous Year Questions with Answers & Explanations

Questions

Cataract is caused by all except:

Large, white keratic precipitates (mutton-fat KPs) are characteristically seen in?

Which of the following conditions is least likely to cause proptosis?

What is the normal aqueous production rate in the human eye?

Maximum correction of myopia can be done by?

Which Goldmann type is considered the standard in perimetry?

During retinoscopy of a 30-year-old male, which cycloplegic is used routinely?

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

In specular microscopy endothelial density is measured by?

Q10

Normal level of visual acuity is attained at which age

NEET-PG 2013 - Ophthalmology NEET-PG Practice Questions and MCQs

Question 1: Cataract is caused by all except:

A. Ultraviolet radiation
B. Infrared radiation
C. Microwave radiation
D. MRI (Correct Answer)

Explanation: ***MRI*** - Magnetic Resonance Imaging (MRI) uses powerful **magnetic fields** and radio waves to generate images, which are not known to cause cataracts. - The energy used in MRI is **non-ionizing** and does not directly damage lens proteins. *Ultraviolet radiation* - Prolonged exposure to **UV-B radiation** is a significant risk factor for the development of various types of cataracts, especially cortical and posterior subcapsular cataracts. - UV radiation can cause oxidative damage to lens proteins and lipids, leading to their aggregation and opacification. *Infrared radiation* - Chronic exposure to high levels of **infrared (IR) radiation**, such as that experienced by glassblowers or steelworkers, can lead to "glassblower's cataract" or "heat cataract." - IR radiation causes thermal damage to the lens, particularly the anterior capsule and subcapsular region. *Microwave radiation* - High-intensity **microwave radiation** has been implicated in the formation of cataracts, particularly in occupational exposure scenarios. - It causes thermal effects within the lens due to absorption of energy, leading to protein denaturation and opacification.

Question 2: Large, white keratic precipitates (mutton-fat KPs) are characteristically seen in?

A. Hemorrhagic uveitis
B. Old healed uveitis
C. Granulomatous uveitis (Correct Answer)
D. Acute anterior uveitis

Explanation: ***Granulomatous uveitis*** - **Mutton-fat keratic precipitates (KPs)** are large, greasy-appearing white deposits on the corneal endothelium, characteristic of **granulomatous inflammation**. - These KPs are composed of macrophages and epithelioid cells, reflecting a **chronic, cell-mediated immune response** seen in granulomatous conditions. *Hemorrhagic uveitis* - This condition involves significant **intraocular bleeding**, which would manifest as hyphema or vitreous hemorrhage, not mutton-fat KPs. - While inflammation may be present, the defining feature is blood, which obscures vision differently than KPs. *Old healed uveitis* - After uveitis heals, KP morphology can change, often appearing smaller, more pigmented, or forming distinct patterns such as **Arlt's triangle**, but not typically actively large, white mutton-fat KPs. - Healed KPs often reflect a less active or resolved inflammatory process, unlike fresh mutton-fat KPs. *Acute anterior uveitis* - This typically presents with smaller, finer, and more numerous **non-granulomatous KPs** (sometimes called "stellate KPs"), in contrast to the large, greasy mutton-fat KPs. - The inflammation is usually acute and less focally organized compared to granulomatous forms.

Question 3: Which of the following conditions is least likely to cause proptosis?

A. Sarcoidosis
B. Myxoedema (Correct Answer)
C. Grave's disease
D. Pituitary adenoma

Explanation: ***Myxoedema*** - **Myxoedema** is associated with severe **hypothyroidism** and is characterized by non-pitting edema due to the accumulation of **glycosaminoglycans** in tissues. - While it can cause facial puffiness, it is **least likely** to cause **proptosis** as there is no direct mechanism for an increase in orbital contents to push the eye forward. *Grave's disease* - **Grave's disease** is the most common cause of **proptosis** due to **immune-mediated inflammation** and accumulation of **glycosaminoglycans** and fat in the orbital tissues, leading to expansion. - This condition specifically affects the **extraocular muscles** and fat, causing bulging of the eyes. *Sarcoidosis* - **Orbital sarcoidosis** can cause **proptosis** due to the formation of **granulomas** within the orbit, leading to mass effect and inflammation. - It can affect any part of the eye and orbit, leading to varied clinical presentations including axial or non-axial globe displacement. *Pituitary adenoma* - A **pituitary adenoma** itself does not directly cause proptosis as it is located in the **sella turcica**, posterior to the orbits. - However, **large adenomas** can cause proptosis indirectly if they invade the **cavernous sinus** and obstruct venous return from the orbit, or if they are associated with **acromegaly**, which can lead to bony overgrowth of the orbital structures and surrounding tissues.

Question 4: What is the normal aqueous production rate in the human eye?

A. 2 µl/min (Correct Answer)
B. 2 ml/min
C. 5 ml/min
D. 5 µl/min

Explanation: ***2 µl/min*** - The ciliary body in the human eye continuously produces **aqueous humor** at a typical rate of approximately **2.0-3.0 µl/min**. - This rate is crucial for maintaining **intraocular pressure (IOP)** and providing nutrients to avascular eye structures like the **cornea** and **lens**. - This translates to approximately **3-4 ml per day** of aqueous humor production. *2 ml/min* - This rate is significantly **higher** than the actual production of aqueous humor, which is measured in microliters per minute. - Such a high production rate would lead to a rapid and severe increase in **intraocular pressure**, causing damage to the eye. *5 ml/min* - This value is an **excessively high** rate of fluid production and is not physiologically correct for aqueous humor. - It would result in unsustainable and damaging **intraocular pressure** levels. *5 µl/min* - While closer to the correct order of magnitude, **5 µl/min** is generally considered to be at the higher end or slightly above the average physiological range for aqueous humor production. - Most sources cite the normal range as being between **2-3 µl/min**.

Question 5: Maximum correction of myopia can be done by?

A. Radial keratotomy
B. LASIK (Correct Answer)
C. Photorefractive keratectomy
D. Orthokeratology

Explanation: ***LASIK*** - **LASIK (Laser-Assisted In Situ Keratomileusis)** allows for significant correction of high myopia by reshaping the cornea with an excimer laser. - It involves creating a **corneal flap** and then ablating tissue underneath, offering precise and stable vision correction for a wide range of refractive errors. - Among the given corneal refractive procedures, LASIK can correct myopia up to **-10 to -12 D**. *Radial keratotomy* - **Radial keratotomy (RK)** involves making radial incisions in the cornea to flatten it, primarily used for low to moderate myopia (up to -3 to -4 D). - It has a higher risk of **unpredictable outcomes**, induced astigmatism, and glare compared to modern laser procedures. *Photorefractive keratectomy* - **Photorefractive keratectomy (PRK)** involves direct ablation of the corneal surface without creating a flap, which is suitable for moderate myopia (up to -8 to -10 D). - While effective, PRK typically has a **longer recovery period** and more post-operative pain than LASIK. *Orthokeratology* - **Orthokeratology (Ortho-K)** uses specially designed rigid contact lenses worn overnight to temporarily reshape the cornea and correct myopia. - The effect is **temporary**, requiring continuous lens wear to maintain vision correction, and is generally limited to low to moderate myopia (up to -4 to -6 D).

Question 6: Which Goldmann type is considered the standard in perimetry?

A. Goldmann type I (small stimulus size)
B. Goldmann type II (medium-small stimulus size)
C. Goldmann type IV (large stimulus size)
D. Goldmann type III (commonly used stimulus size) (Correct Answer)

Explanation: ***Goldmann type III (commonly used stimulus size)*** - This stimulus size is the **international standard** for kinetic perimetry and ensures comparability of visual field charts worldwide. - It provides a balance between **sensitivity** and minimizing the effects of **pupil size** and other ocular factors. *Goldmann type I (small stimulus size)* - While very small, this stimulus type is **not the standard** for general perimetry. - It is sometimes used for detecting **subtle defects** or for patients with very good visual acuity, but its small size can make it harder to detect. *Goldmann type II (medium-small stimulus size)* - This stimulus size is **smaller than the standard** and is not universally adopted for perimetry. - It offers slightly more sensitivity than the standard but can be more affected by **refractive errors** or media opacities. *Goldmann type IV (large stimulus size)* - This stimulus is **much larger than the standard** and is typically used for detecting **gross defects** or in patients with severely impaired vision. - Its large size makes it **less sensitive** to smaller visual field abnormalities.

Question 7: During retinoscopy of a 30-year-old male, which cycloplegic is used routinely?

A. Homatropine 2% drop
B. Cyclopentolate 1% drop (Correct Answer)
C. Atropine 1% ointment
D. None of the options

Explanation: ***Cyclopentolate 1% drop*** - When cycloplegia is required for retinoscopy, **cyclopentolate 1%** is the preferred agent in adults due to its **rapid onset** (30-60 minutes) and **intermediate duration** (6-24 hours). - It provides adequate **cycloplegia** (paralysis of accommodation) to reveal the full refractive error without the prolonged effects of atropine. - **Clinical note:** In routine practice, most adults aged 30 years undergo retinoscopy **without cycloplegia** as accommodation is usually not a significant factor. Cycloplegia in adults is reserved for specific indications like suspected latent hyperopia, accommodative spasm, or unreliable subjective refraction. *Homatropine 2% drop* - Homatropine has a **slower onset** (1 hour) and **longer duration** (1-3 days) compared to cyclopentolate, making it less practical for routine diagnostic use. - It is typically used for therapeutic purposes such as in **anterior uveitis** to provide cycloplegia and mydriasis. *Atropine 1% ointment* - Atropine is the **strongest** and **longest-acting** cycloplegic with effects lasting **7-14 days**, which is excessively long for diagnostic retinoscopy. - It is primarily used in **young children** (especially under 5 years) for accurate refraction and in therapeutic settings for **cycloplegic refraction in amblyopia** treatment. *None of the options* - While it's true that **routine retinoscopy in a healthy 30-year-old adult** typically does NOT require cycloplegia, this question asks which cycloplegic would be used **when indicated**. - Among the available cycloplegic options, **cyclopentolate** remains the appropriate choice for adults when cycloplegia is deemed necessary.

Question 8: Which of the following conditions is NOT diagnosed by fluorescein angiography?

A. Diabetes retinopathy
B. Hypertensive retinopathy (Correct Answer)
C. Central serous retinopathy
D. Choroidal neovascularization

Explanation: ***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

Question 9: In specular microscopy endothelial density is measured by?

A. None of the options
B. Optical doubling
C. Fixed frame analysis (Correct Answer)
D. Optical focusing

Explanation: ***Fixed frame analysis*** - This is the **standard method** used in specular microscopy to measure corneal endothelial cell density. - It involves analyzing a specific, fixed area of the **endothelial mosaic** and counting the number of cells within that defined frame. - The cell count from this fixed area is then **extrapolated** to calculate the overall endothelial cell density (cells/mm²). - This technique provides **quantitative assessment** of endothelial health, which is crucial for evaluating corneal function and pre-operative assessment for intraocular surgeries. *Optical doubling* - This is not a standard method for measuring endothelial density in specular microscopy. - Optical doubling relates to **refractive phenomena** or optical measurement techniques used in other contexts, not for endothelial cell counting. *Optical focusing* - While **essential for image acquisition**, optical focusing is merely a preliminary step to obtain a clear, sharp image of the endothelium. - It does not measure or count cells; it only ensures proper visualization before analysis. - The actual measurement requires subsequent **cell counting methods** like fixed frame analysis. *None of the options* - Incorrect because **fixed frame analysis** is indeed the recognized and widely used method for measuring endothelial density in specular microscopy.

Question 10: Normal level of visual acuity is attained at which age

A. 6 months
B. 1 year
C. 3 years
D. 6 years (Correct Answer)

Explanation: ***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.