Which of the following statements about pterygium is false?
Silk retina is seen in ?
Pseudopapilledema with tigroid fundus appearance is seen in?
1mm change in axial length of the eyeball would change the refracting power of the eye by?
A 30 year old man presents to the clinic with pain in the eye, watering, redness, and photophobia. Examination of his eyes shows circumcorneal congestion and keratic precipitates. Assertion: Keratic precipitates (KPs) are proteinaceous deposits that can occur in various patterns on the corneal endothelium. Reason: Mutton fat KPs are seen in granulomatous iridocyclitis and are composed of epithelioid cells and macrophages.
What is regular astigmatism?
Which of the following is not a standard treatment for myopia?
Sudden loss of vision without pain - Which of the following is NOT a cause?
All are true regarding cornea except:
Aniseikonia is ?
NEET-PG 2015 - Ophthalmology NEET-PG Practice Questions and MCQs
Question 11: Which of the following statements about pterygium is false?
- A. Arise from any part of conjunctiva (Correct Answer)
- B. Can cause astigmatism
- C. Surgery is treatment of choice
- D. UV exposure is risk factor
Explanation: ***Arise from any part of conjunctiva*** **(FALSE - Correct Answer)** - This statement is **FALSE** and thus the correct answer. - Pterygium characteristically arises from the **nasal (interpalpebral) bulbar conjunctiva** in 90-95% of cases. - It does NOT arise from "any part" - it has a specific predilection for the medial (nasal) limbus in the palpebral fissure zone. - Temporal pterygium is much less common (~10% of cases). *Can cause astigmatism* **(TRUE)** - This statement is TRUE. - As a pterygium grows across the cornea, it can induce **corneal astigmatism** by altering the curvature of the cornea. - This irregular corneal surface can blur vision, especially as the pterygium progresses towards the central visual axis. *Surgery is treatment of choice* **(TRUE)** - This statement is TRUE. - **Surgical excision** is the primary treatment for pterygium when it is symptomatic, threatens vision, or causes significant cosmetic concerns. - Indications for surgery include: growth towards the visual axis, inducing high astigmatism, significant discomfort, or cosmetic desire. - Adjunctive measures (mitomycin C, conjunctival autograft) help reduce recurrence. *UV exposure is risk factor* **(TRUE)** - This statement is TRUE. - **Ultraviolet (UV) radiation exposure** is a well-established and significant risk factor for the development and progression of pterygium. - This explains its higher prevalence in individuals living in sunny climates (between 37° N and 37° S latitude - "pterygium belt") and those with outdoor occupations.
Question 12: Silk retina is seen in ?
- A. Retinal detachment (Correct Answer)
- B. Diabetic retinopathy
- C. Macular degeneration
- D. Hypertensive retinopathy
Explanation: ***Retinal detachment*** - **"Silk retina" or "silky sheen"** is a classic ophthalmoscopic finding in retinal detachment, describing the **smooth, glistening appearance** of the detached sensory retina. - The detached retina appears **elevated, gray, and translucent** with characteristic folds or undulations, exhibiting a **satiny or silky luster** when examined. - Patients typically present with **photopsias (flashes of light)**, **floaters**, and progressive **visual field defect** described as a "curtain" or "shadow." - This is a true **ophthalmic emergency** requiring urgent surgical intervention. *Diabetic retinopathy* - Characterized by **microaneurysms, dot-blot hemorrhages, hard exudates**, and **cotton-wool spots** in non-proliferative stages. - Proliferative diabetic retinopathy shows **neovascularization** and vitreous hemorrhage. - Does not produce the "silk retina" appearance. *Macular degeneration* - Age-related macular degeneration presents with **drusen, pigmentary changes**, and in advanced stages, **geographic atrophy** or **choroidal neovascularization**. - May show a **"beaten-bronze" appearance** in certain macular dystrophies (Best's disease), but not "silk retina." - Central vision loss is the predominant symptom. *Hypertensive retinopathy* - Features include **generalized arteriolar narrowing, AV nicking, flame-shaped hemorrhages**, and **cotton-wool spots**. - In severe cases (Grade IV), **optic disc edema** and macular star exudates may occur. - Vascular changes dominate the clinical picture, not a silky retinal appearance.
Question 13: Pseudopapilledema with tigroid fundus appearance is seen in?
- A. Astigmatism
- B. Presbyopia
- C. Hypermetropia
- D. Myopia (Correct Answer)
Explanation: ***Myopia*** - **Pseudopapilledema** with a **tigroid fundus** (tessellated or salt-and-pepper appearance) is characteristically observed in high myopia due to the oblique entry of the **optic nerve** into the globe and thinning of the choroid and retinal pigment epithelium. - The pseudopapilledema is caused by the crowding of axons and glial tissue within the optic disc, giving a raised appearance, and is distinct from true papilledema which involves **optic disc edema** due to increased **intracranial pressure**. - The tigroid fundus results from the visibility of underlying **choroidal vessels** through the attenuated retinal pigment epithelium in the stretched, elongated myopic eye. *Hypermetropia* - **Hypermetropia** (farsightedness) typically presents with a small, compact optic disc, but does not exhibit the specific findings of **pseudopapilledema** or tigroid fundus. - This condition is characterized by the eye being too short or the lens having insufficient power, causing light to focus behind the retina. *Astigmatism* - **Astigmatism** is characterized by an **irregularly shaped cornea** or lens, leading to blurred vision at all distances. - While it can cause some distortion, it is not associated with the specific optic disc appearance of **pseudopapilledema** or the fundus changes seen in high myopia. *Presbyopia* - **Presbyopia** is an age-related condition where the eye's natural lens loses its flexibility, making it difficult to focus on **near objects**. - It affects the **accommodative ability** of the eye and does not manifest with any characteristic changes in the optic disc morphology such as **pseudopapilledema** or retinal/choroidal changes.
Question 14: 1mm change in axial length of the eyeball would change the refracting power of the eye by?
- A. 1D
- B. 2D
- C. 3D (Correct Answer)
- D. 4D
Explanation: ***3D*** - A 1mm change in the **axial length** of the eyeball leads to an approximate **3 diopter (D) change** in the refractive power of the eye. - This relationship is crucial for understanding **refractive errors** like myopia (if the eyeball is too long) or hyperopia (if it's too short). *1D* - A 1D change in refractive power corresponds to a much larger change in the **focal length** of the eye, not typically 1mm in axial length. - This value is too small to reflect the significant impact of a 1mm axial length alteration on the eye's focusing ability. *2D* - While a direct relationship exists, 2D is an **underestimation** of the actual refractive change caused by a 1mm alteration in axial length. - This value would imply a less sensitive optical system than the human eye. *4D* - A 4D change would represent an **overestimation** of the refractive power change for a 1mm alteration in axial length. - Such a high value is generally seen with more substantial anatomical variations or surgical interventions.
Question 15: A 30 year old man presents to the clinic with pain in the eye, watering, redness, and photophobia. Examination of his eyes shows circumcorneal congestion and keratic precipitates. Assertion: Keratic precipitates (KPs) are proteinaceous deposits that can occur in various patterns on the corneal endothelium. Reason: Mutton fat KPs are seen in granulomatous iridocyclitis and are composed of epithelioid cells and macrophages.
- A. Both Assertion and Reason are true, and Reason is the correct explanation for Assertion
- B. Both Assertion and Reason are true, and Reason is not the correct explanation for Assertion (Correct Answer)
- C. Assertion is true, but Reason is false
- D. Assertion is false but reason is true
Explanation: ***Both Assertion and Reason are true, and Reason is not the correct explanation for Assertion*** **Why both statements are true:** - The **Assertion** is correct: Keratic precipitates (KPs) are inflammatory cell and protein deposits that adhere to the **corneal endothelium** and can present in various patterns including fine dusty KPs, medium-sized KPs, and large mutton fat KPs. - The **Reason** is also correct: **Mutton fat KPs** are characteristic of **granulomatous anterior uveitis** (granulomatous iridocyclitis) and consist of aggregations of **epithelioid cells and macrophages**, appearing as large, greasy, white deposits. **Why Reason does NOT explain Assertion:** - The Reason describes a **specific type** of KP (mutton fat) and its cellular composition in one particular form of inflammation (granulomatous). - The Assertion makes a **general statement** about KPs occurring in various patterns. - The Reason does not explain **why** KPs can occur in various patterns or what determines these different patterns - it only describes one specific pattern. *Incorrect: Both true with Reason explaining Assertion* - The Reason is too specific and only describes one type of KP, not the general mechanism of pattern variation. *Incorrect: Assertion true, Reason false* - Both statements are medically accurate and well-established in ophthalmology literature. *Incorrect: Assertion false, Reason true* - KPs are well-documented deposits on the corneal endothelium in various forms of uveitis, making the Assertion true.
Question 16: What is regular astigmatism?
- A. Astigmatism in which the principal meridians are parallel
- B. Asymptomatic astigmatism
- C. Astigmatism as a result of cataract surgery
- D. Astigmatism where the principal meridians are at a 90-degree angle to each other (Correct Answer)
Explanation: ***Astigmatism where the principal meridians are at a 90-degree angle to each other.*** - In **regular astigmatism**, the two principal meridians of the eye's refractive power are **perpendicular** (90 degrees apart), meaning they are not random. - This perpendicularity allows for correction with **sphero-cylindrical lenses**, as the different focal powers are along well-defined axes. *Astigmatism in which the principal meridians are parallel* - This statement is incorrect as it describes a non-existent or mischaracterized form of astigmatism; for astigmatism to occur, there must be a **difference in curvature** and thus power between two meridians, which cannot be parallel and distinct. - While meridians are typically measured, the concept of **parallel principal meridians** does not align with the definition of astigmatism. *Asymptomatic astigmatism* - This describes the **presence of astigmatism without noticeable symptoms**, not the type of astigmatism itself. - Astigmatism can be asymptomatic, particularly if it is of a **low magnitude**, but this term does not define its optical characteristics. *Astigmatism as a result of cataract surgery* - This refers to **induced astigmatism**, often post-surgical, which can be regular or irregular. - **Surgically induced astigmatism** is a cause, not a classification of astigmatism based on the orientation of its principal meridians.
Question 17: Which of the following is not a standard treatment for myopia?
- A. Phakic intraocular lens
- B. Radial Keratotomy
- C. Holmium laser thermoplasty (Correct Answer)
- D. LASIK
Explanation: ***Holmium laser thermoplasty*** - This procedure was explored for the treatment of **hyperopia**, not myopia, as it aims to steepen the cornea to increase its refractive power. - It involves using a holmium laser to apply heat to the peripheral cornea, causing **collagen shrinkage** and steepening, which is the opposite of what is needed for myopia correction. *LASIK* - **LASIK (Laser-Assisted in Situ Keratomileusis)** is a common and effective surgical procedure for correcting myopia by reshaping the cornea to reduce its refractive power. - It involves creating a **corneal flap** and using an excimer laser to remove tissue from the underlying stromal bed. *Phakic intraocular lens* - **Phakic intraocular lenses (IOLs)** are implanted into the eye without removing the natural lens and are a standard treatment for moderate to high myopia, especially in patients not suitable for LASIK. - They work by adding refractive power to the eye, allowing light to focus correctly on the retina. *Radial Keratotomy* - **Radial Keratotomy (RK)** was an early surgical procedure for myopia, involving making radial incisions in the cornea to flatten it and reduce its refractive power. - Although largely replaced by LASIK due to its unpredictable outcomes and potential for glare and night vision problems, it was historically a standard treatment for myopia.
Question 18: Sudden loss of vision without pain - Which of the following is NOT a cause?
- A. CRAO
- B. CSR
- C. Acute congestive glaucoma (Correct Answer)
- D. Vitreous Hemorrhage
Explanation: ***Acute congestive glaucoma*** - This condition is characterized by **sudden, severe eye pain** along with blurred vision, redness, and a fixed, mid-dilated pupil. - The pain arises from abrupt elevation of **intraocular pressure**, which differentiates it from painless vision loss. *CRAO* - **Central Retinal Artery Occlusion** (CRAO) typically presents as **sudden, profound, painless monocular vision loss**. - Funduscopic examination often reveals a **cherry-red spot** in the fovea with generalized retinal whitening. *CSR* - **Central Serous Retinopathy** (CSR) causes **sudden, painless blurred vision** or a scotoma, often described as a "watery" or "shimmering" effect. - It involves leakage of fluid under the retina, typically in the macula. *Vitreous Hemorrhage* - Presents as **sudden, painless loss of vision** or a shower of floaters, often described as cobwebs or clouds. - It results from bleeding into the **vitreous cavity**, which can obscure the retina.
Question 19: All are true regarding cornea except:
- A. The cornea is richly vascular. (Correct Answer)
- B. Endothelium help in maintaining dehydrated state
- C. Oxygen is mostly derived by epithelium directly from the air through tear film
- D. Corneal thickness is greater at periphery than center
Explanation: ***The cornea is richly vascular.*** - The cornea is an **avascular** tissue, meaning it lacks blood vessels, which is crucial for its transparency. - This avascularity helps prevent light scatter and maintains clear vision. - The cornea receives nutrition from the **aqueous humor**, **tear film**, and **limbal blood vessels** through diffusion. *Endothelium help in maintaining dehydrated state* - The **corneal endothelium** actively pumps fluid out of the corneal stroma via **Na-K-ATPase pumps**, preventing swelling and maintaining its relative state of dehydration. - This **deturgescence** is essential for the cornea's transparency and optimal refractive power. *Oxygen is mostly derived by epithelium directly from the air through tear film* - The corneal **epithelium** primarily obtains oxygen directly from the atmosphere via the **tear film** when the eyes are open. - During sleep, oxygen is primarily supplied by the **palpebral conjunctival vessels**. *Corneal thickness is greater at periphery than center* - The cornea is **thinner at the center** (around 520-540 µm) and gradually **thicker towards the periphery** (around 600-640 µm). - This structural difference contributes to its optical properties and mechanical stability.
Question 20: Aniseikonia is ?
- A. Projection of different colored images into the visual cortex of one eye
- B. Change in the perception of object size due to distance
- C. Temporary visual disturbances affecting one eye
- D. Projection of different sized images into visual cortex of two retinae (Correct Answer)
Explanation: ***Projection of different sized images into visual cortex of two retinae*** - **Aniseikonia** is a condition where the **magnification of images** projected onto the retinas of each eye differs, leading to a difference in perceived image size. - This difference can cause diplopia, spatial distortion, and other visual discomforts, often due to **refractive error differences** between the eyes. *Projection of different colored images into the visual cortex of one eye* - This describes a form of **dyschromatopsia** or color vision deficiency, specifically if restricted to one eye, but it is not aniseikonia. - Aniseikonia concerns the **size** of an image, not its color. *Change in the perception of object size due to distance* - This is a normal phenomenon related to **perspective** and the brain's interpretation of visual cues, not a pathological condition like aniseikonia. - Aniseikonia involves an actual difference in retinal image size, independent of observer-object distance. *Temporary visual disturbances affecting one eye* - This description is too general and could refer to various conditions such as a **migraine aura** or a transient monocular vision loss (**amaurosis fugax**). - Aniseikonia is a persistent discrepancy in image size between the eyes, not necessarily temporary and not limited to affecting only one eye's function in isolation.